Uterotubal Junction of the Bovine (Bos taurus) vs. the Dromedary Camel (Camelus dromedarius): Histological and Histomorphometry Analysis

Uterotubal Junction of the Bovine (Bos taurus) vs. the Dromedary Camel (Camelus dromedarius): Histological and Histomorphometry Analysis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Uterotubal Junction of the Bovine (Bos taurus) vs. the Dromedary Camel (Camelus dromedarius): Histological and Histomorphometry Analysis Ahmed Sabry Abdoon, Seham S. Soliman, Ahmed N. Mohamed This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-2999187/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract This study compares the histomorphology differences of cattle uterotubal junction (CUTJ) and dromedary camels uterotubal junction papilla (CUTJP). UTJ were dissected from eight cows and twelve camels with dominant follicles, and processed for H&E staining for morphology, histology, and histomorphometry examination. The results showed that the CUTJP existed only in camels and was completely absent in cattle. Histologically, CUTJ appears with a star-shaped lumen, and the mucosa lined by a simple columnar epithelium containing ciliated and non-ciliated cells, superficial (SG), and deep glands (D G) were abundant in the submucosa. CUTJP is a fibrous conical structure, it has a pale yellowish color and 0.5 ± 0.2 cm height and 0.3 ± 0.1 cm width. C UTJP, the lumen is wider, and the mucosa showed large multiple folds lined with ciliated and non-ciliated pseudostratified columnar epithelium. The submucosa showed no endometrial glands. Lumen area, lumen epithelial height, luminal epithelial density, the thickness of the muscular layer, number of folds, folds height, epithelial height, fold area, and epithelial perimeter were higher in CUTJP (P < 0.001) than CUTJ. While the total endometrial area and glandular epithelial density were lower in UTJP (P < 0.001) than in CUTJ. In conclusion, the epithelial lining, absence of glands, and the thick layer of tunica muscularis might indicate that camel CUTJP could play a mechanical role in selecting spermatozoa and assisting the hatching of blastocysts during their passage through it. Biological sciences/Biochemistry Biological sciences/Evolution Biological sciences/Physiology Cattle Dromedary camel Uterotubal junction Papilla Histomorphometry Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Background Camels have anatomical, physiological, behavioral, and reproductive peculiarities that make them differ from other mammals. Female dromedary camels present unique reproductive peculiarities compared with other domestic livestock, including induced ovulation 1 , spontaneous parthenogenetic development of oocytes 2 , 3 , the two uterine horns showed distinct luteolytic activity, resulting in the establishment of left horn pregnancies 4 . Early maternal recognition of pregnancy by Day 10, embryo migration from the right to left uterine horns for implantation 5 . In camelids, between 6- and 6.5-days post ovulation, the embryo reaches the uterus at the early hatched blastocyst stage, while cleavage and embryo development before the hatched blastocyst stage take place in the oviduct and hatches before it descends to the uterus is mandatory for the embryo to continue to develop 6 . Information on the mechanisms of the mechanical hatching of blastocyst before descending to the uterus is unknown in camels. A functioning oviduct is required for gamete storage, maturation, fertilization, and early embryonic development 7 . The oviduct is a fibromuscular structure that connects the ovary to the uterus, it is elongated, and tubular 8 . The uterotubal junction (UTJ), which connects the uterine tube to the uterine horn, is the uterine part of the isthmus and/or the last few millimeters of the extramural isthmus, and the cranial tip of the uterine horn 9 . In mammals, the structure of both the oviduct and uterus showed great diversity in morphological and functional features 10 . There have been reports of species differences in the interface between the uterine tube (isthmus) and the uterine horn 11 . In the cow and sheep, the uterine tube simply opens into the uterine horn 11 . Whereas, in camelids, at the uterotubal junction, the isthmus opened into the uterine horn with a distinct papilla (UTJP) toward the uterine side 5,12−14 . The basic role, morphology, and description of UTJP are still unidentified in the camel. A microscopic papilla is present at the UTJ in cheetahs 9 . In the mare, the uterine tube opens into the uterine horn with the ostium forming a barrier against ascending infection 15 . The isthmus opens in dog and mouse by a slit-like ostium on a mound that projects into the uterine lumen 11 . The UTJ has been proven to be a major barrier to the passage of sperm in dogs 16 , cats 17 , and pigs 18 . Changes in the uterotubal junction microstructure are required to facilitate specific functions for this region. Knowledge of these differences could provide scientific bases for the development of reproductive biotechnology, especially in a species like camel. Therefore, understanding the reproductive biology of the camel is essential, including an in-depth description of the anatomy and histology of the UTJP. This is the first study to investigate the histological and morphometric analysis of UTJP in dromedary camels to enhance our understanding of the role of this region in camels. Materials and methods Ethical approval This experiment was approved by the Institutional Medical Research Ethical Committee, National Research Centre, Egypt (Project ID: 13050416). The work was conducted under the provision of relevant Egyptian laws, World Health Organization (WHO), and Good Medical and Laboratory Practice (GCP and GLP) guidelines. The experimental work was conducted during the period from Feb 2023 to April 2023. The whole work was conducted on slaughterhouse materials only. Collection of the reproductive tract In the present study reproductive tract of eight cows at the proestrus phase (the presence of regressed CL and at least one dominant follicle) and the reproductive tract of twelve mature nonpregnant dromedary camels at the mature follicular phase (in which the ovary showed at least one dominant follicle with 1.3–1.7 cm in diameter 1 . All samples were collected after the slaughter at a local abattoir (El Bassatein slaughterhouse, Cairo, Egypt). Immediately after collection, an incision was made along the dorsal surfaces of the left and right uterine horns of the reproductive tract of cows and dromedary camels, and the cow's uterotubal junction (UTJ) and camel uterotubal junction papilla (UTJP) were separated from uterine tissue and the length and width of the UTJP were recorded. All measurements were made using a vernier caliper to the nearest mm. Histological examination For 48 h, cows UTJ and camel’s UTJP were fixed in 10% neutral buffered formalin at room temperature, then dehydrated in ascending grades of alcohol, cleared in xylene, and embedded in paraffin wax. Tissue blocks were cut using a rotatory microtome into 5-µm sections and placed on glass slides. Sections were rehydrated through a series of decreasing concentrations of ethanol and stained with hematoxylin and eosin stains 19 . A light microscope was used to examine the slides, and photomicrographs from the selected tissues were taken using a digital camera. Morphometric analysis The sections cows UTJ and camels UTJP stained with H&E were examined using an Olympus research microscope CX41 (Olympus, Japan), and the digital photomicrographs sections were photographed at different magnifying powers with an Olympus SC100 digital CCD camera (Olympus, Japan). Fifteen captured images for the representative areas from cows UTJ and camel’s UTJP were exported and analyzed using Image J analysis software (ImageJ 1. x version) 20 . The threshold of the signals was set to identify the selected parameters and subtract the background noise (Figure 1). Different morphometric analysis parameters of uterine sections at the level of the uterotubal junction of camel and cow including luminal epithelium height (µm) from the base of the membrane to the tip of luminal epithelial cells, luminal area (µm) (Figure 1A). In addition, total endometrial area (mm 2 ) was measured, letting calculation of stromal density, luminal epithelium density, and glandular epithelium density as a percentage of the total endometrium (Figure 1B). Moreover, the thickness of the muscular layer was determined. Gland duct numbers, the height of the epithelial lining (µm), density, perimeters, and areas of superficial (SG) and deep glands (DG) were assessed in different endometrial compartments. For camel’s UTJP morphometric parameters were estimated including the total number, height of epithelial cells from the base of the membrane to the tip of the epithelial cell, length, density, and area. Ten random measurements of each parameter of the selected areas were estimated per sample. Statistical analysis All statistical tests were carried out using GraphPad Prism 9 (GraphPad Software, Inc., CA, and USA). Differences between parameters were analyzed by unpaired Student’s t-test. All data are presented as means ± SEM. Results Gross morphology The gross morphology of the cattle’s UTJ and camel’s UTJP is shown in Figure 2. The UTJP has existed only in camels and is completely absent in cows. In cattle, the oviduct opens directly into the uterine horn and the UTJ extends up to the first uterine caruncle (Fig. 2A, Arrow). While in dromedary camel the UTJP is a fibrous conical structure protruding from the base of the oviduct toward the tip of the uterine horn, it has a pale yellowish color and 0.5± 0.2 cm height and 0.3±0.1 cm width (Fig. 2B). Light microscopy Light microscopic examination revealed that the cattle’s UTJ and camel’s UTJP differ in structure, the size of the lumen, the shape of the mucosa, and the thickness of the tunica muscularis. In cross-section, the cattle’s UTJ appears with a star-shaped lumen that lies centrally and the mucosal layer forms low transversal ridges. Cattle’s UTJ consists of the three layers of mucosa, myometrium, and serosa. The mucosa consists of primary folds and the submucosa is enriched with simple tubular glands opening directly to the lumen (Fig. 3A). The openings of the uterine glands are mostly situated in the furrows separating the transversal ridges. In cattle TUJ, the mucosa is lined by a simple columnar epithelium containing ciliated and non-ciliated cells (Fig. 3C). Whereas in cross-section in camel’s UTJP consists of the three layers of mucosa, myometrium, and serosa. The lumen is wider, and the mucosa showed large numerous primary folds that branched forming secondary and sometimes tertiary folds (Fig. 3B). In camel’s UTJP the mucosa is lined with ciliated and non-ciliated pseudostratified columnar epithelium (Fig. 3D). The sub mucosa showed no endometrial glands. In addition, microscopic examination of cattle’s UTJ indicated that the tunica muscularis is thin and consists of inner circular and outer longitudinal muscles (Fig. 4A). While, in the dromedary camel, the tunica muscularis is double the thickness of that of cattle and consists of inner circular and outer longitudinal muscles (Fig. 4B). Morphometric analysis The morphometric analysis of camel’s UTJP and cattle’s UTJ showed significant differences between the two species (Table 1 and Figure 5). The morphometric analysis of camel UTJP and cattle UTJ showed significant differences in the lumen area which were higher in camel UTJP (P < 0.001) compared to cattle UTJ. Also, the thickness of the muscular layer was significantly (P < 0.001) higher in camel's UTJP than in cattle UTJ. The lumen epithelium density percentage was higher in camel’s UTJP (P < 0.001) compared to cattle’s UTJ. On the other hand, the total endometrial area and the glandular epithelial density was lower in camel UTJP (P < 0.001) compared to cattle UTJ. While there was no significant difference in stromal density percentage between camels and cattle. Data presented in Table 2 and Figure 6 indicated that the morphometric analysis of the UTJ folds significantly differ between camels UTJP and cattle UTJ, higher number of folds were recorded in camel UTJP (P = 0.0025) compared to cattle UTJ. Additionally, the length of folds and epithelium height of the camel UTJP were greater than those of cattle UTJ (P = 0.0023, P < 0.001), respectively. Moreover, the perimeter and area of the folds were also higher in camels UTJP (P = 0.0299, P = 0.0448, respectively) compared to cattle UTJ. The uterine glands were absent in camel’s UTJP, while in cattle, there were plenty of superficial (SG) and deep glands (DG), (Table 3 and Figure 7). The average number of uterine glands was 348.0 ± 8.643 per cross-section for both SG and DG. The epithelium height, perimeter, and area of SG were significantly (P < 0.001) higher than DG. However, the density of DG was higher (P < 0.001) than SG. Discussion There are species differences in the junction between the uterine tube (isthmus) and uterine horn, and the role played by the UTJ is affected by different factors, which greatly vary among mammals. In the present work, the cattle’s UTJ and camel’s UTJP were investigated by histological and histomorphometric examination as a fundamental knowledge for further biotechnological and clinical application. This study indicated that the morphology and histology within the cattle’s UTJ and camel’s UTJP differ depending on their functions. In the present work, the UTJP exists in camels and is completely absent in cattle. Similarly, UTJP was previously reported in dromedary camel 5,12-14 . However, the details regarding its morphology and morphometry are lacking. Dromedary camel’s UTJP has a conical shape directed from the base of the oviduct toward the uterine lumine, it has a pale yellowish color, 0.5± 0.2 cm height, and 0.3±0.1 cm width. The luminal area, luminal epithelial density, and the thickness of tunica muscularis is higher in camel UTJP than that of cattle UTJ. Moreover, camels UTJP possess a higher number of uterine folds, high folds height, higher epithelium height, and higher fold area compared to cattle UTJ. This unique feature is attributed to the formation of primary, secondary, and occasionally tertiary folds. This difference compared with other mammals could be related to the regional function. In the dromedary camel, the function of the uterotubal junction papilla is lacking. Furthermore, in cattle’s UTJ, the mucosa consists of primary folds lined with ciliated and non-ciliated simple columnar epithelium, and the submucosa enriched with simple tubular glands open directly into the lumen. These results are consistent with that previously reported in cattle 21 . Several species indicate increased ciliogenesis under the influence of estradiol 22 , and non-ciliated cells may have the ability to transform into ciliated cells following estradiol treatment 23 . Whereas, in the dromedary camel’s UTJP, the mucosa consists of primary, secondary, and tertiary folds lined with ciliated and non-ciliated pseudostratified columnar epithelium, and the submucosa showed no endometrial glands. Similarly, the uterotubal junction in camel is lined by ciliated and non-ciliated pseudostratified columnar epithelium 14 . In contrast, the oviduct of the camel is lined by ciliated and non-ciliated columnar epithelium 13 . This variation could be related to regional differences in the or the reproductive status of the camels. Camels are induced ovulatory and follicular waves continue to develop during the breeding season. The height of the lining epithelium increased during the follicular wave in response to the high serum concentrations of estradiol 1 . High estrogen levels caused an increase in cellular proliferation, uterine epithelial cell secretion, uterine blood flow, and endometrial vascular permeability 24 . In addition, in cattle’s UTJ, the tunica muscularis is thin and consists of inner circular and outer longitudinal muscles. While, in the dromedary camel, the tunica muscularis is nearly double the thickness of that of cattle and consists of inner circular and outer longitudinal muscles. The significance of the absence of uterine glands and the thick tunica muscularis of the camel’s UTJP is unknown. The varying thickness of the tunica muscularis between the two species suggests that it is related to the function of this region. Contractions of the tunica muscularis may cause stenosis of the utero-tubal junction resulting in restriction and regulation of the sperm passage towards the isthmus; or descent of oocyte and fertilized zygote to the uterus 25 . Furthermore, the thick tunica muscularis might serve to provide the peristaltic and anti-peristaltic waves in the isthmus. Peristaltic contractions of these thick muscles together with the movement of the cilia could help in the passage of the early embryo toward the uterus 26 . Therefore, the thick tunica muscularis camel’s UTJP might play a role in regulating the passage of sperm from the uterus to the oviduct. In addition, it could play a role in the hatching of blastocyst before it descends from the isthmus into the uterine lumine. In Llama, the hatching of the blastocyst in the oviduct is mandatory before they descend to continue to develop in the uterus 6 . Therefore, the morphological, histological, and morphometric characteristics of the camel’s UTJP might play a significant role in selecting sperm before passage to the oviduct for fertilization, and hatching of the blastocyst might be a mechanical process that occurred during the passage of the blastocyst through the UTJP in dromedary camel. Furthermore, in this work, in cattle, there were plenty of superficial (SG) and deep uterine glands (DG). The epithelium height, perimeter, and area of SG were significantly higher than DG. However, the density of DG was higher than SG. This increase in superficial endometrial glands might occur due to the reduction in uterine edema of the subepithelial connective tissue layer. Similar results were recorded in buffalo 27 . In mammals, the UTJ acts as a reservoir for sperm storage in the preovulatory phase because it contains abundant uterine glands. After mating the sperm enters the uterus and aggregate at the terminals of the uterine horns, which clump together and adhere to the ciliated epithelium in the dog to conserve energy until ovulation and the ova entering the ampulla 28 . Passage of motile sperm through the UTJ is regulated by both the physical constraints of the UTJ opening, resulting in only a privileged population of sperm, and molecular screening of the sperm 28,29 . The ciliated epithelium of the UTJ has the capability of screening the proteins on the acrosome of the sperm and allowing the passage of selected sperm 29 . In contrast, the total number of superficial and deep endometrial glands in cows was unchanged between the estrous cycle, but the area of the subepithelial connective tissue layer enlarged at the follicular phase 30 . In our case, the samples were collected with unknown reproductive history, but it seems that it collected from cyclic animals during the follicular phase of the estrous cycle. In addition, the absence of uterine glands in camel’s UTJP requires further studies on the mechanism of sperm storage before ovulation and screening the different parts of the uterus to localize the area of sperm storage. In conclusion, this study revealed several interesting morphological and histological features of the camel’s UTJP such as the epithelial lining, absence of glands, and the presence of a thick layer of tunica muscularis might indicate that this part of the oviduct plays a mechanical process in selecting spermatozoa and assisting of blastocyst hatching during their passage through it. In Conclusion: Camel UTJP is a specialized structure found at the UTJ, several interesting morphological and histological features of the camel UTJP such as the epithelial lining, absence of uterine glands, and the thick tunica muscularis might indicate that this part of the oviduct plays mechanical process in selecting spermatozoa and assist of blastocyst hatching during their passage through it. Further research is needed to fully understand the molecular mechanisms underlying the papillae function, which could have important implications for improving reproduction in camels. Declarations Ethics approval and consent to participate. Not applicable. Consent for publication Not applicable. Availability of data and material The data are available upon reasonable request from the corresponding author. Competing interests The authors declare no conflict of interest. Authors’ contributions ASSA conceived the study design, ASSA, SSS, ANM performed the experiments, ANM analyzed data, and ASSA wrote the manuscript. All authors read and approved the final manuscript. Acknowledgments : This research was supported by the National Research Centre of Egypt through the research grant ID: 13050413. We are thankful to Prof Nabil A. Hemida, Faculty of Veterinary Medicine Cairo University for constructive criticism of the manuscript and careful English revision. References Skidmore, J.A. Reproductive physiology in female Old-World Camelids. Anim Reprod Sci.124(3–4),148 – 54 (2011). doi: 10.1016/j.anireprosci.2010.08.023 . Abdoon, A.S.S, Kandil, O.M., Zeng, S.M. & Cui, M. Mitochondrial distribution, ATP-GSH contents, calcium [Ca2+] oscillation during in vitro maturation of dromedary camel oocytes. Theriogenology 76, 1207–1214 (2011). Abdoon, A.S.S., Kandil, O.M. & Zeng, S.M. Intrafollicular spontaneous parthenogenetic development of dromedary camel oocytes. 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Reproduction 134(2), 365–371 (2007). doi: 10.1530/REP-06-0133 . Tables Table 1 Morphometric analysis of camel’s UTJP and cattle’s UTJ (Mean ± SEM). Parameters Camel’s UTJP Cattle’s UTJ Luminal area (µm) 48706 ± 400.5*** 23427 ± 385.1 Total endometrial area (density) (mm 2 ) 46.89 ± 2.31 73.223 ± 2.78*** Stroma density (% of total endometrium) 73.20 ± 1.03 72.89 ± 1.34 Luminal epith. density (% of total endometrium) 24.84 ± 0.69*** 6.02 ± 0.47 The thickness of the muscular layer 393.30 ± 30.24*** 178.30 ± 19.76 Glandular epith. density (% of total endometrium). 0.00 21.24 ± 0.8976*** *** Significantly differ between rows at P < 0.0001 Table 2 Mean ± SEM morphometric characteristics of the UTJ folds of cattle and camel. Parameters Camel UTJP folds Cattle UTJ folds Total number of folds 11.80 ± 1.594** 5.4 ± 1.140 Epithelium height (µm) 58.06 ± 4.033*** 24.968 ± 4.094 Length of folds (µm) 276.0 ± 24.66** 153 ± 12.263 The perimeter of folds (µm) 995.7 ± 141.6* 561.062 ± 172.511 Folds area (µm) 30989 ± 5866* 15238 ± 4908 * Significantly differ between rows at P < 0.05 ** Significantly differ between rows at P < 0.01 *** Significantly differ between rows at P < 0.001 Table 3 Mean ± SE morphometric measurements of endometrial glands in cattle’s UTJ. Parameters Superficial Glands Deep Glands Total number of uterine gland ducts 348.0 ± 8.643 Epithelium height (µm) 25.17 ± 2.007** 18.37 ± 0.8242 Gland duct density 24.43 ± 1.305 36.42 ± 1.233*** Gland duct perimeter (µm) 582.7 ± 20.96*** 303.3 ± 11.50 Gland duct area (µm) 12854 ± 573.0*** 4776 ± 275.8 ** Significantly differ between rows at P < 0.001 *** Significantly differ between rows at P < 0.0001 Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-2999187","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":206129046,"identity":"030f89ff-8844-4219-853e-97432ef862d2","order_by":0,"name":"Ahmed Sabry Abdoon","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3klEQVRIiWNgGAWjYJACZgY2IMneAOGxEa+F5wDJWiQSiHQUf/8Bxs8FZTZy5pJvj334wVAnz8fAfPgFPi0SNxKYpWecSzO2nJ2XPLOH4bBhGwNbmgVea24wMEjzth1O3HA7x5iZgeFAAhsDj5kBPh3y5w8w/wZruXkGpKUOqIX/G14tBkBjIbbc4AFpYQbZwvwAnxbDG4lt1iC/GJzJMWbsMQD6hZnNDK9X5M4fPnwbFGIGx88YM/yoqJOXb29+/AGvHgbGBmR3MoCjSQK/FiyAmYAto2AUjIJRMMIAAB56P2uKuTt7AAAAAElFTkSuQmCC","orcid":"","institution":"National Research Centre","correspondingAuthor":true,"prefix":"","firstName":"Ahmed","middleName":"Sabry","lastName":"Abdoon","suffix":""},{"id":206129047,"identity":"40de226c-9930-4ad5-9ead-081cf52e0679","order_by":1,"name":"Seham S. Soliman","email":"","orcid":"","institution":"National Research Centre","correspondingAuthor":false,"prefix":"","firstName":"Seham","middleName":"S.","lastName":"Soliman","suffix":""},{"id":206129048,"identity":"0dfaeb1e-5328-47c5-a5b3-c12ada0977ec","order_by":2,"name":"Ahmed N. Mohamed","email":"","orcid":"","institution":"National Research Centre","correspondingAuthor":false,"prefix":"","firstName":"Ahmed","middleName":"N.","lastName":"Mohamed","suffix":""}],"badges":[],"createdAt":"2023-05-30 09:14:13","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-2999187/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-2999187/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":38044699,"identity":"b2ac6a18-11d0-4d58-b047-b93a13472d01","added_by":"auto","created_at":"2023-06-05 17:37:22","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":662123,"visible":true,"origin":"","legend":"\u003cp\u003eThreshold ranges of the staining signal are set to identify the selected parameters and subtract the background noise of cross-sections at (A) bovine UTJ; (B) camel’s UTJP.\u003c/p\u003e","description":"","filename":"1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2999187/v1/5d5d853e306dd897590e0bcf.jpeg"},{"id":38045732,"identity":"3243e242-8491-4ff0-8dff-c1d1dff6c738","added_by":"auto","created_at":"2023-06-05 17:45:22","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":331681,"visible":true,"origin":"","legend":"\u003cp\u003eGross morphology of (A) bovine UTJ; (B) camel’s UTJP (White arrow).\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-2999187/v1/2e041e21c8145bc2a3b6204e.jpg"},{"id":38045913,"identity":"8a974e6e-f21b-4476-bcc1-50b81ca5cae5","added_by":"auto","created_at":"2023-06-05 17:53:22","extension":"jpeg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":172221,"visible":true,"origin":"","legend":"\u003cp\u003ePhotomicrograph\u003cstrong\u003e \u003c/strong\u003eshowing the histological difference between cattle’s UTJ and camel’s UTJP; A) cross-section in cattle’s UTJ showing star-like lumen and abundance of the uterine gland (Black arrow) (40x); B) camel’s UTJP showing mucosal folds and muscular layer (40x); C) Ciliated (White arrow) and non-ciliated simple columnar epithelium lining mucosa of cattle’s UTJ; D) Ciliated (Black arrows) and non-ciliated pseudostratified columnar epithelial cells lining mucosa of camel’s UTJP (400x). H\u0026amp;E stain, scale bar A, B= 100 µm; and C, D= 25µm.\u003c/p\u003e","description":"","filename":"3.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2999187/v1/565f23b761a77073e9d08bbd.jpeg"},{"id":38044694,"identity":"146777e7-c05d-4b99-a66d-e2465a1c6dde","added_by":"auto","created_at":"2023-06-05 17:37:22","extension":"jpeg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":205201,"visible":true,"origin":"","legend":"\u003cp\u003ePhotomicrograph\u003cstrong\u003e \u003c/strong\u003eshowing the histological difference between cattle’s UTJ and camel’s UTJP A) muscular layer of cattle’s UTJ (400x); B) muscular layer in camel’s UTJP showed double the size of cattle’s UTJ (400x). H\u0026amp;E (Scale bar A, B= 50 µm)\u003cstrong\u003e.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"4.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2999187/v1/f6b50ac8cc9cf0d2d6cd4918.jpeg"},{"id":38044692,"identity":"62743265-1e53-45b0-a7fb-7f5b712a00ec","added_by":"auto","created_at":"2023-06-05 17:37:21","extension":"jpeg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":70304,"visible":true,"origin":"","legend":"\u003cp\u003eMorphometric analysis parameters of camel’s UTJP and cattle’s UTJ. a) Luminal epithelium height (µm); b) Luminal area (µm); c) Total endometrial area (mm\u003csup\u003e2\u003c/sup\u003e); d) Thickness of the muscular layer (µm); e) Stroma density (% of total endometrium); and f) Luminal epith. density (% of total endometrium).\u003c/p\u003e","description":"","filename":"5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2999187/v1/2e776f61ae8440ab8964e504.jpeg"},{"id":38044693,"identity":"372535cf-7a9e-4ff0-9471-636c83c161bd","added_by":"auto","created_at":"2023-06-05 17:37:22","extension":"jpeg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":56739,"visible":true,"origin":"","legend":"\u003cp\u003eMorphometric analysis uterine folds of camel and cattle UTJ. a) total number; b) epithelium height (µm); c) length (µm); d) Perimeter (µm); e) area (µm).\u003c/p\u003e","description":"","filename":"6.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2999187/v1/fc3cebbf3b7d7a924b10bbb3.jpeg"},{"id":38045730,"identity":"858cc874-1fcf-4d4d-a3a3-96514034d4fc","added_by":"auto","created_at":"2023-06-05 17:45:22","extension":"jpeg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":52625,"visible":true,"origin":"","legend":"\u003cp\u003eMorphometric measurements of endometrial glands in cattle’s UTJ. a) Epithelium height (µm); b) Gland duct density; c) Gland duct perimeter (µm); and d) Gland duct area (µm). ** Significantly differ between rows at P\u0026lt;0.01, *** Significantly differ between rows at P\u0026lt;0.001\u003c/p\u003e","description":"","filename":"7.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-2999187/v1/ed78e9724a020978de174967.jpeg"},{"id":42870462,"identity":"ee9b9783-f283-444a-a399-16127513317f","added_by":"auto","created_at":"2023-09-09 05:52:27","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":766844,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2999187/v1/30a3fb42-b6f4-4bd4-aa1b-da1e99e446a9.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Uterotubal Junction of the Bovine (Bos taurus) vs. the Dromedary Camel (Camelus dromedarius): Histological and Histomorphometry Analysis","fulltext":[{"header":"Background","content":"\u003cp\u003eCamels have anatomical, physiological, behavioral, and reproductive peculiarities that make them differ from other mammals. Female dromedary camels present unique reproductive peculiarities compared with other domestic livestock, including induced ovulation\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e, spontaneous parthenogenetic development of oocytes\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e,\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e, the two uterine horns showed distinct luteolytic activity, resulting in the establishment of left horn pregnancies\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e. Early maternal recognition of pregnancy by Day 10, embryo migration from the right to left uterine horns for implantation\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e. In camelids, between 6- and 6.5-days post ovulation, the embryo reaches the uterus at the early hatched blastocyst stage, while cleavage and embryo development before the hatched blastocyst stage take place in the oviduct and hatches before it descends to the uterus is mandatory for the embryo to continue to develop\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e. Information on the mechanisms of the mechanical hatching of blastocyst before descending to the uterus is unknown in camels.\u003c/p\u003e \u003cp\u003eA functioning oviduct is required for gamete storage, maturation, fertilization, and early embryonic development\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e. The oviduct is a fibromuscular structure that connects the ovary to the uterus, it is elongated, and tubular\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e. The uterotubal junction (UTJ), which connects the uterine tube to the uterine horn, is the uterine part of the isthmus and/or the last few millimeters of the extramural isthmus, and the cranial tip of the uterine horn\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e. In mammals, the structure of both the oviduct and uterus showed great diversity in morphological and functional features\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e. There have been reports of species differences in the interface between the uterine tube (isthmus) and the uterine horn\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e. In the cow and sheep, the uterine tube simply opens into the uterine horn\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e. Whereas, in camelids, at the uterotubal junction, the isthmus opened into the uterine horn with a distinct papilla (UTJP) toward the uterine side\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e5,12\u0026minus;14\u003c/span\u003e\u003c/sup\u003e. The basic role, morphology, and description of UTJP are still unidentified in the camel. A microscopic papilla is present at the UTJ in cheetahs\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e. In the mare, the uterine tube opens into the uterine horn with the ostium forming a barrier against ascending infection\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e. The isthmus opens in dog and mouse by a slit-like ostium on a mound that projects into the uterine lumen\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e. The UTJ has been proven to be a major barrier to the passage of sperm in dogs\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e, cats\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e, and pigs\u003csup\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eChanges in the uterotubal junction microstructure are required to facilitate specific functions for this region. Knowledge of these differences could provide scientific bases for the development of reproductive biotechnology, especially in a species like camel. Therefore, understanding the reproductive biology of the camel is essential, including an in-depth description of the anatomy and histology of the UTJP. This is the first study to investigate the histological and morphometric analysis of UTJP in dromedary camels to enhance our understanding of the role of this region in camels.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003e\u003cstrong\u003eEthical approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis experiment was approved by the Institutional Medical Research Ethical Committee, National Research Centre, Egypt (Project ID: 13050416). The work was conducted under the provision of relevant Egyptian laws, World Health Organization (WHO), and Good Medical and Laboratory Practice (GCP and GLP) guidelines. The experimental work was conducted during the period from Feb 2023 to April 2023. The whole work was conducted on slaughterhouse materials only.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCollection of the reproductive tract\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the present study reproductive tract of eight cows at the proestrus phase (the presence of regressed CL and at least one dominant follicle) and the reproductive tract of twelve mature nonpregnant dromedary camels at the mature follicular phase (in which the\u0026nbsp;ovary showed at least one dominant follicle with 1.3\u0026ndash;1.7 cm in diameter\u003cu\u003e\u003csup\u003e1\u003c/sup\u003e\u003c/u\u003e.\u0026nbsp;All samples were collected after the slaughter at a local abattoir (El Bassatein slaughterhouse, Cairo, Egypt).\u0026nbsp;Immediately after collection, an incision was made along the dorsal surfaces of the left and right uterine horns of the reproductive tract of cows and dromedary camels, and the cow\u0026apos;s uterotubal junction (UTJ) and camel uterotubal junction papilla (UTJP) were separated from uterine tissue and the length and width of the UTJP were recorded. All measurements were made using a vernier caliper to the nearest mm.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eHistological examination\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFor 48 h, cows UTJ and camel\u0026rsquo;s UTJP were fixed in 10% neutral buffered formalin at room temperature, then dehydrated in ascending grades of alcohol, cleared in xylene, and embedded in paraffin wax. Tissue blocks were cut\u0026nbsp;using a rotatory microtome\u0026nbsp;into 5-\u0026micro;m sections and placed on glass slides. Sections were rehydrated through a series of decreasing concentrations of ethanol and\u0026nbsp;stained with hematoxylin and eosin stains\u003cu\u003e\u003csup\u003e19\u003c/sup\u003e\u003c/u\u003e. A light microscope was used to examine the slides, and photomicrographs from the selected tissues were taken using a digital camera.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMorphometric analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe sections cows UTJ and camels UTJP stained with H\u0026amp;E were examined using an Olympus research microscope CX41 (Olympus, Japan), and the digital photomicrographs sections were photographed at different magnifying powers with an Olympus SC100 digital CCD camera (Olympus, Japan). Fifteen captured images for the representative areas from cows UTJ and camel\u0026rsquo;s UTJP were exported and analyzed using Image J analysis software (ImageJ 1. x version)\u003cu\u003e\u003csup\u003e20\u003c/sup\u003e\u003c/u\u003e. The threshold of the signals was set to identify the selected parameters and subtract the background noise (Figure 1). Different morphometric analysis parameters of uterine sections at the level of the uterotubal junction of camel and cow including luminal epithelium height (\u0026micro;m) from the base of the membrane to the tip of luminal epithelial cells, luminal area (\u0026micro;m) (Figure 1A). In addition, total endometrial area (mm\u003csup\u003e2\u003c/sup\u003e) was measured, letting calculation of stromal density, luminal epithelium density, and glandular epithelium density as a percentage of the total endometrium (Figure 1B). Moreover, the thickness of the muscular layer was determined. Gland duct numbers, the height of the epithelial lining (\u0026micro;m), density, perimeters, and areas of superficial (SG) and deep glands (DG) were assessed in different endometrial compartments. For camel\u0026rsquo;s UTJP morphometric parameters were estimated including the total number, height of epithelial cells from the base of the membrane to the tip of the epithelial cell, length, density, and area. Ten random measurements of each parameter of the selected areas were estimated per sample.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll statistical tests were carried out using GraphPad Prism 9 (GraphPad Software, Inc., CA, and USA). Differences between parameters were analyzed by unpaired Student\u0026rsquo;s t-test. All data are presented as means \u0026plusmn; SEM. \u0026nbsp;\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eGross morphology\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe gross morphology of the cattle\u0026rsquo;s UTJ and camel\u0026rsquo;s UTJP is shown in Figure 2. The UTJP has existed only in camels and is completely absent in cows. In cattle, the oviduct opens directly into the uterine horn and the UTJ extends up to the first uterine caruncle (Fig. 2A, Arrow). While in dromedary camel the UTJP is a fibrous conical structure protruding from the base of the oviduct toward the tip of the uterine horn, it has a pale yellowish color and 0.5\u0026plusmn; 0.2 cm height and 0.3\u0026plusmn;0.1 cm width (Fig. 2B).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLight microscopy\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLight microscopic examination revealed that the cattle\u0026rsquo;s UTJ and camel\u0026rsquo;s UTJP differ in structure, the size of the lumen, the shape of the mucosa, and the thickness of the tunica muscularis. \u0026nbsp; In cross-section, the cattle\u0026rsquo;s UTJ appears with a star-shaped lumen that lies centrally and the mucosal layer forms low transversal ridges. Cattle\u0026rsquo;s UTJ consists of the three layers of mucosa, myometrium, and serosa. The mucosa consists of primary folds and the submucosa is enriched with simple tubular glands opening directly to the lumen (Fig. 3A). The openings of the uterine glands are mostly situated in the furrows separating the transversal ridges. In cattle TUJ, the mucosa is lined by a simple columnar epithelium containing ciliated and non-ciliated cells (Fig. 3C). Whereas in cross-section in camel\u0026rsquo;s UTJP consists of the three layers of mucosa, myometrium, and serosa. The lumen is wider, and the mucosa showed large numerous primary folds that branched forming secondary and sometimes tertiary folds (Fig. 3B). In camel\u0026rsquo;s UTJP the mucosa is lined with ciliated and non-ciliated pseudostratified columnar epithelium (Fig. 3D). The sub mucosa showed no endometrial glands.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn addition, microscopic examination of cattle\u0026rsquo;s UTJ indicated that the tunica muscularis is thin and consists of inner circular and outer longitudinal muscles (Fig. 4A). While, in the dromedary camel, the tunica muscularis is double the thickness of that of cattle and consists of inner circular and outer longitudinal muscles (Fig. 4B).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMorphometric analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe morphometric analysis of camel\u0026rsquo;s UTJP and cattle\u0026rsquo;s UTJ showed significant differences between the two species (Table 1 and Figure 5).\u0026nbsp;The\u0026nbsp;morphometric\u0026nbsp;analysis\u0026nbsp;of\u0026nbsp;camel\u0026nbsp;UTJP\u0026nbsp;and\u0026nbsp;cattle\u0026nbsp;UTJ\u0026nbsp;showed\u0026nbsp;significant\u0026nbsp;differences\u0026nbsp;in the\u0026nbsp;lumen\u0026nbsp;area\u0026nbsp;which\u0026nbsp;were\u0026nbsp;higher\u0026nbsp;in\u0026nbsp;camel\u0026nbsp;UTJP\u0026nbsp;(P\u0026nbsp;\u0026lt;\u0026nbsp;0.001) compared\u0026nbsp;to\u0026nbsp;cattle\u0026nbsp;UTJ.\u0026nbsp;Also,\u0026nbsp;the thickness\u0026nbsp;of the\u0026nbsp;muscular\u0026nbsp;layer\u0026nbsp;was\u0026nbsp;significantly\u0026nbsp;(P\u0026nbsp;\u0026lt;\u0026nbsp;0.001)\u0026nbsp;higher\u0026nbsp;in\u0026nbsp;camel\u0026apos;s\u0026nbsp;UTJP\u0026nbsp;than\u0026nbsp;in\u0026nbsp;cattle\u0026nbsp;UTJ.\u0026nbsp;The lumen epithelium density percentage was higher in camel\u0026rsquo;s UTJP (P \u0026lt; 0.001) compared to cattle\u0026rsquo;s UTJ.\u0026nbsp;On\u0026nbsp;the\u0026nbsp;other\u0026nbsp;hand,\u0026nbsp;the\u0026nbsp;total\u0026nbsp;endometrial\u0026nbsp;area and the\u0026nbsp;glandular epithelial density\u0026nbsp;was\u0026nbsp;lower in\u0026nbsp;camel\u0026nbsp;UTJP\u0026nbsp;(P\u0026nbsp;\u0026lt; 0.001) compared\u0026nbsp;to\u0026nbsp;cattle UTJ.\u0026nbsp;While\u0026nbsp;there\u0026nbsp;was\u0026nbsp;no significant\u0026nbsp;difference\u0026nbsp;in\u0026nbsp;stromal\u0026nbsp;density percentage\u0026nbsp;between camels\u0026nbsp;and\u0026nbsp;cattle.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eData presented in Table 2 and Figure 6 indicated that the morphometric analysis of the UTJ folds significantly differ between camels UTJP and cattle UTJ, higher number of folds were recorded in camel UTJP (P = 0.0025) compared to cattle UTJ. Additionally, the length of folds and epithelium height of the camel UTJP were greater than those of cattle UTJ (P = 0.0023, P \u0026lt; 0.001), respectively. Moreover, the perimeter and area of the folds were also higher in camels UTJP (P = 0.0299, P = 0.0448, respectively) compared to cattle UTJ.\u003c/p\u003e\n\u003cp\u003eThe uterine glands were absent in camel\u0026rsquo;s UTJP, while in cattle, there were plenty of superficial (SG) and deep glands (DG), (Table 3 and Figure 7). The average number of uterine glands was 348.0 \u0026plusmn; 8.643 per cross-section for both SG and DG. The epithelium height, perimeter, and area of SG were significantly (P \u0026lt; 0.001) higher than DG. However, the density of DG was higher (P \u0026lt; 0.001) than SG.\u0026nbsp;\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThere are species differences in the junction between the uterine tube (isthmus) and uterine horn, and the role played by the UTJ is affected by different factors, which greatly vary among mammals.\u0026nbsp;In the present work, the cattle\u0026rsquo;s UTJ and camel\u0026rsquo;s UTJP were investigated by histological and histomorphometric examination as a fundamental knowledge for further biotechnological and clinical application. This study indicated that the morphology and histology within the cattle\u0026rsquo;s UTJ and camel\u0026rsquo;s UTJP differ depending on their functions.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn the present work, the UTJP exists in camels and is completely absent in cattle. Similarly, UTJP was previously reported in dromedary camel\u003cu\u003e\u003csup\u003e5,12-14\u003c/sup\u003e\u003c/u\u003e. However, the\u0026nbsp;details regarding its morphology and morphometry are lacking. Dromedary camel\u0026rsquo;s UTJP\u0026nbsp;has a conical shape directed from the base of the oviduct toward the uterine lumine,\u0026nbsp;it has a pale yellowish color, 0.5\u0026plusmn; 0.2 cm height, and 0.3\u0026plusmn;0.1 cm width. The luminal area, luminal epithelial density, and the thickness of tunica muscularis is higher in camel UTJP than that of cattle UTJ.\u0026nbsp;Moreover, camels UTJP possess a higher number of uterine folds, high folds height, higher epithelium height, and higher fold area compared to cattle UTJ. This unique feature is attributed to the formation of primary, secondary, and occasionally tertiary folds. This difference compared with other mammals could be related to the regional function. In the dromedary camel, the function of the uterotubal junction papilla is lacking. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFurthermore, in cattle\u0026rsquo;s UTJ, the mucosa consists of primary folds lined with ciliated and non-ciliated simple columnar epithelium, and the submucosa enriched with simple tubular glands open directly into the lumen. These results are consistent with that previously reported in cattle\u003cu\u003e\u003csup\u003e21\u003c/sup\u003e\u003c/u\u003e.\u0026nbsp;Several species indicate increased ciliogenesis under the influence of estradiol\u003cu\u003e\u003csup\u003e22\u003c/sup\u003e\u003c/u\u003e, and non-ciliated cells may have the ability to transform into ciliated cells following estradiol treatment\u003cu\u003e\u003csup\u003e23\u003c/sup\u003e\u003c/u\u003e. Whereas, in the dromedary camel\u0026rsquo;s UTJP, the mucosa consists\u0026nbsp;of primary, secondary, and tertiary folds lined with ciliated and non-ciliated pseudostratified columnar epithelium, and the submucosa showed no endometrial glands. Similarly, the uterotubal junction in camel is lined by ciliated and non-ciliated pseudostratified columnar epithelium\u003cu\u003e\u003csup\u003e14\u003c/sup\u003e\u003c/u\u003e. In contrast, the oviduct of the camel is lined by ciliated and non-ciliated columnar epithelium\u003cu\u003e\u003csup\u003e13\u003c/sup\u003e\u003c/u\u003e. This\u0026nbsp;variation could be related to regional differences in the or the reproductive status of the camels. Camels are induced ovulatory and follicular waves continue to develop during the breeding season. The\u0026nbsp;height of the lining epithelium increased during the follicular wave in response to the high serum concentrations of estradiol\u003cu\u003e\u003csup\u003e1\u003c/sup\u003e\u003c/u\u003e.\u0026nbsp;High estrogen levels caused an increase in cellular proliferation, uterine epithelial cell secretion, uterine blood flow, and endometrial vascular permeability\u003cu\u003e\u003csup\u003e24\u003c/sup\u003e\u003c/u\u003e.\u003c/p\u003e\n\u003cp\u003eIn addition, in cattle\u0026rsquo;s UTJ, the tunica muscularis is thin and consists of inner circular and outer longitudinal muscles. While, in the dromedary camel, the tunica muscularis is nearly double the thickness of that of cattle and consists of inner circular and outer longitudinal muscles. The significance of the absence of uterine glands and the thick tunica muscularis of the camel\u0026rsquo;s UTJP is unknown.\u0026nbsp;The varying thickness of the tunica muscularis between the two species suggests that it is related to the function of this region. Contractions of the tunica muscularis may cause stenosis of the utero-tubal junction resulting in restriction and regulation of the sperm passage towards the isthmus; or descent of oocyte and fertilized zygote to the uterus\u003cu\u003e\u003csup\u003e25\u003c/sup\u003e\u003c/u\u003e.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eFurthermore, the thick tunica muscularis might serve to provide the peristaltic and anti-peristaltic waves in the isthmus. Peristaltic contractions of these thick muscles together with the movement of the cilia could help in the passage of the early embryo toward the uterus\u003cu\u003e\u003csup\u003e26\u003c/sup\u003e\u003c/u\u003e. Therefore, the thick tunica muscularis camel\u0026rsquo;s UTJP might play a role in regulating the passage of sperm from the uterus to the oviduct. In addition, it could play a role in the hatching of blastocyst before it descends from the isthmus into the uterine lumine. In Llama, the hatching of the blastocyst in the oviduct is mandatory before they descend to continue to develop in the uterus\u003cu\u003e\u003csup\u003e6\u003c/sup\u003e\u003c/u\u003e. Therefore, the morphological, histological, and morphometric characteristics of the camel\u0026rsquo;s UTJP might play a significant role in selecting sperm before passage to the oviduct for fertilization, and hatching of the blastocyst might be a mechanical process that occurred during the passage of the blastocyst through the UTJP in dromedary camel.\u003c/p\u003e\n\u003cp\u003eFurthermore, in this work, in cattle, there were plenty of superficial (SG) and deep uterine glands (DG). The epithelium height, perimeter, and area of SG were significantly higher than DG. However, the density of DG was higher than SG. This increase in\u0026nbsp;superficial endometrial glands might occur due to the reduction in uterine edema of the subepithelial connective tissue layer. Similar results were recorded in buffalo\u003cu\u003e\u003csup\u003e27\u003c/sup\u003e\u003c/u\u003e. In mammals, the UTJ acts as a reservoir for sperm storage in the preovulatory phase because it contains abundant uterine glands. After mating the sperm enters the uterus and aggregate at the terminals of the uterine horns, which clump together and adhere to the ciliated epithelium in the dog to conserve energy until ovulation and the ova entering the ampulla\u003cu\u003e\u003csup\u003e28\u003c/sup\u003e\u003c/u\u003e. Passage of motile sperm through the UTJ is regulated by both the physical constraints of the UTJ opening, resulting in only a privileged population of sperm, and molecular screening of the sperm\u003cu\u003e\u003csup\u003e28,29\u003c/sup\u003e\u003c/u\u003e. The ciliated epithelium of the UTJ has the capability of screening the proteins on the acrosome of the sperm and allowing the passage of selected sperm\u003cu\u003e\u003csup\u003e29\u003c/sup\u003e\u003c/u\u003e. In contrast, the total number of superficial and deep endometrial glands in cows was unchanged between the estrous cycle, but the area of the subepithelial connective tissue layer enlarged at the follicular phase\u003cu\u003e\u003csup\u003e30\u003c/sup\u003e\u003c/u\u003e. In our case, the samples were collected with unknown reproductive history, but it seems that it collected from cyclic animals during the follicular phase of the estrous cycle. In addition, the absence of uterine glands in camel\u0026rsquo;s UTJP requires further studies on the mechanism of sperm storage before ovulation and screening the different parts of the uterus to localize the area of sperm storage.\u003c/p\u003e\n\u003cp\u003eIn conclusion, this study revealed several interesting morphological and histological features of the camel\u0026rsquo;s UTJP such as the epithelial lining, absence of glands, and the presence of a thick layer of tunica muscularis might indicate that this part of the oviduct plays a mechanical process in selecting spermatozoa and assisting of blastocyst hatching during their passage through it.\u003c/p\u003e\n\u003cp\u003eIn Conclusion: Camel UTJP is a specialized structure found at the UTJ, several interesting morphological and histological features of the camel UTJP such as the epithelial lining, absence of uterine glands, and the thick tunica muscularis might indicate that this part of the oviduct plays mechanical process in selecting spermatozoa and assist of blastocyst hatching during their passage through it. \u0026nbsp;Further research is needed to fully understand the molecular mechanisms underlying the papillae function, which could have important implications for improving reproduction in camels.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data are available upon reasonable request from the corresponding author.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eASSA conceived the study design, ASSA, SSS, ANM performed the experiments, ANM analyzed data, and ASSA wrote the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e: This research was supported by the National Research Centre of Egypt through the research grant ID: 13050413. We are thankful to Prof Nabil A. Hemida, Faculty of Veterinary Medicine Cairo University for constructive criticism of the manuscript and careful English revision.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSkidmore, J.A. Reproductive physiology in female Old-World Camelids. 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Theory and Practice of Histological Techniques. 2nd Edn, 2010, Churchill Livingstone, New York.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchneider, C.A., Rasband, W.S. \u0026amp; Eliceiri, K.W. \"NIH Image to ImageJ: 25 years of image analysis\". \u003cem\u003eNature methods\u003c/em\u003e 9(7), 671\u0026ndash;675 (2012), PMID 22930834.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWrobel, K.H., Kujat, R. \u0026amp; Fehle, G. The bovine tubouterine junction: general organization and surface morphology. Cell Tissue Res 271, 227\u0026ndash;239(1993). doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/BF00318609\u003c/span\u003e\u003cspan address=\"10.1007/BF00318609\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDonnez,.J, Casanas-Roux, F., Caprasse, J., Ferin, J. \u0026amp; Thomas, K. Cyclic changes in ciliation, cell height, and mitotic activity in human tubal epithelium during reproductive life. Fertil Steril 43, 554\u0026ndash;559 (1985). doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/s0015-0282(16)48496-7\u003c/span\u003e\u003cspan address=\"10.1016/s0015-0282(16)48496-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBajpai, V.K., Pathak, R.K., Shipstone, A.C., Harper, M.J.K. \u0026amp; Herbert, D.C. Does interconversion occur in tubal epithelium? \u003cem\u003eAnat Rec\u003c/em\u003e 196, 12A-13A (1980).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarnes, F.L. The effects of the early uterine environment on the subsequent development of embryo and fetus. \u003cem\u003eTheriogenology\u003c/em\u003e 53(2), 649\u0026ndash;658 (2000). doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/s0093-691x(99)00264-2\u003c/span\u003e\u003cspan address=\"10.1016/s0093-691x(99)00264-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSuarez, SS. Sperm transport and motility in the mouse oviduct: Observations \u003cem\u003ein situ. Biol Reprod\u003c/em\u003e. 36 (1): 203\u0026ndash;210 (1987). doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1095/biolreprod36.1.203\u003c/span\u003e\u003cspan address=\"10.1095/biolreprod36.1.203\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAyen, E., Shahrooz, R. \u0026amp; Kazemie, S. Histological and histo-morphometrical changes of different regions of oviduct during follicular and luteal phases of estrus cycle in adult Azarbaijan buffalo. Iran J Vet Res. 13(1), 42\u0026ndash;48 (2012).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTienthai, P. \u0026amp; Sajjarengpong, K. Morphological aspects by light and scanning electron microscopic studies of swamp buffalo endometrium at follicular and mid-luteal phases. Thai J Vet Med. 43(1): 23\u0026ndash;32 (2013).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEngland, G.C.W., Burgess, C.M., Clutterbuck, A.L. \u0026amp; Freeman, S.L. Epithelial surface changes and spermatozoa storage in the reproductive tract of the bitch. Vet J 195, 185\u0026ndash;191 (2013). doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.tvjl.2012.12.003\u003c/span\u003e\u003cspan address=\"10.1016/j.tvjl.2012.12.003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSuarez, S.S. Mammalian sperm interactions with the female reproductive tract. Cell Tissue Res. 363, 185\u0026ndash;194 (2016). doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00441-015-2244-2\u003c/span\u003e\u003cspan address=\"10.1007/s00441-015-2244-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang, C.K., Robinson, R.S., Flint, A.P. \u0026amp; Mann, G.E. Quantitative analysis of changes in endometrial gland morphology during the bovine oestrous cycle and their association with progesterone levels. Reproduction 134(2), 365\u0026ndash;371 (2007). doi: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1530/REP-06-0133\u003c/span\u003e\u003cspan address=\"10.1530/REP-06-0133\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":" \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cdiv class=\"SimplePara\"\u003eMorphometric analysis of camel\u0026rsquo;s UTJP and cattle\u0026rsquo;s UTJ (Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SEM).\u003c/div\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eParameters\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eCamel\u0026rsquo;s UTJP\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eCattle\u0026rsquo;s UTJ\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eLuminal area (\u0026micro;m)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e48706\u0026thinsp;\u0026plusmn;\u0026thinsp;400.5***\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e23427\u0026thinsp;\u0026plusmn;\u0026thinsp;385.1\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eTotal endometrial area (density) (mm\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e46.89\u0026thinsp;\u0026plusmn;\u0026thinsp;2.31\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e73.223\u0026thinsp;\u0026plusmn;\u0026thinsp;2.78***\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eStroma density (% of total endometrium)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e73.20\u0026thinsp;\u0026plusmn;\u0026thinsp;1.03\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e72.89\u0026thinsp;\u0026plusmn;\u0026thinsp;1.34\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eLuminal epith. density (% of total endometrium)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e24.84\u0026thinsp;\u0026plusmn;\u0026thinsp;0.69***\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e6.02\u0026thinsp;\u0026plusmn;\u0026thinsp;0.47\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eThe thickness of the muscular layer\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e393.30\u0026thinsp;\u0026plusmn;\u0026thinsp;30.24***\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e178.30\u0026thinsp;\u0026plusmn;\u0026thinsp;19.76\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eGlandular epith. density (% of total endometrium).\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e0.00\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e21.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8976***\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e*** Significantly differ between rows at P\u0026thinsp;\u0026lt;\u0026thinsp;0.0001\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003cbr/\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cdiv class=\"SimplePara\"\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SEM morphometric characteristics of the UTJ folds of cattle and camel.\u003c/div\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eParameters\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eCamel UTJP folds\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eCattle UTJ folds\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eTotal number of folds\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e11.80\u0026thinsp;\u0026plusmn;\u0026thinsp;1.594**\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e5.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.140\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eEpithelium height (\u0026micro;m)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e58.06\u0026thinsp;\u0026plusmn;\u0026thinsp;4.033***\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e24.968\u0026thinsp;\u0026plusmn;\u0026thinsp;4.094\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eLength of folds (\u0026micro;m)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e276.0\u0026thinsp;\u0026plusmn;\u0026thinsp;24.66**\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e153\u0026thinsp;\u0026plusmn;\u0026thinsp;12.263\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eThe perimeter of folds (\u0026micro;m)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e995.7\u0026thinsp;\u0026plusmn;\u0026thinsp;141.6*\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e561.062\u0026thinsp;\u0026plusmn;\u0026thinsp;172.511\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eFolds area (\u0026micro;m)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e30989\u0026thinsp;\u0026plusmn;\u0026thinsp;5866*\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e15238\u0026thinsp;\u0026plusmn;\u0026thinsp;4908\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e* Significantly differ between rows at P\u0026thinsp;\u0026lt;\u0026thinsp;0.05\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e** Significantly differ between rows at P\u0026thinsp;\u0026lt;\u0026thinsp;0.01\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e*** Significantly differ between rows at P\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003cbr/\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cdiv class=\"SimplePara\"\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;SE morphometric measurements of endometrial glands in cattle\u0026rsquo;s UTJ.\u003c/div\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eParameters\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003eSuperficial Glands\u003c/div\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003eDeep Glands\u003c/div\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eTotal number of uterine gland ducts\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e348.0\u0026thinsp;\u0026plusmn;\u0026thinsp;8.643\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eEpithelium height (\u0026micro;m)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e25.17\u0026thinsp;\u0026plusmn;\u0026thinsp;2.007**\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e18.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8242\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eGland duct density\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e24.43\u0026thinsp;\u0026plusmn;\u0026thinsp;1.305\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e36.42\u0026thinsp;\u0026plusmn;\u0026thinsp;1.233***\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eGland duct perimeter (\u0026micro;m)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e582.7\u0026thinsp;\u0026plusmn;\u0026thinsp;20.96***\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e303.3\u0026thinsp;\u0026plusmn;\u0026thinsp;11.50\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cdiv class=\"SimplePara\"\u003eGland duct area (\u0026micro;m)\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cdiv class=\"SimplePara\"\u003e12854\u0026thinsp;\u0026plusmn;\u0026thinsp;573.0***\u003c/div\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cdiv class=\"SimplePara\"\u003e4776\u0026thinsp;\u0026plusmn;\u0026thinsp;275.8\u003c/div\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e** Significantly differ between rows at P\u0026thinsp;\u0026lt;\u0026thinsp;0.001\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e*** Significantly differ between rows at P\u0026thinsp;\u0026lt;\u0026thinsp;0.0001\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003cbr/\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Cattle, Dromedary camel, Uterotubal junction, Papilla, Histomorphometry","lastPublishedDoi":"10.21203/rs.3.rs-2999187/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-2999187/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study compares the histomorphology differences of cattle uterotubal junction (CUTJ) and dromedary camels uterotubal junction papilla (CUTJP). UTJ were dissected from eight cows and twelve camels with dominant follicles, and processed for H\u0026amp;E staining for morphology, histology, and histomorphometry examination. The results showed that the CUTJP existed only in camels and was completely absent in cattle. Histologically, CUTJ appears with a star-shaped lumen, and the mucosa lined by a simple columnar epithelium containing ciliated and non-ciliated cells, superficial (SG), and deep glands (D G) were abundant in the submucosa. CUTJP is a fibrous conical structure, it has a pale yellowish color and 0.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.2 cm height and 0.3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.1 cm width. C UTJP, the lumen is wider, and the mucosa showed large multiple folds lined with ciliated and non-ciliated pseudostratified columnar epithelium. The submucosa showed no endometrial glands. Lumen area, lumen epithelial height, luminal epithelial density, the thickness of the muscular layer, number of folds, folds height, epithelial height, fold area, and epithelial perimeter were higher in CUTJP (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) than CUTJ. While the total endometrial area and glandular epithelial density were lower in UTJP (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) than in CUTJ. In conclusion, the epithelial lining, absence of glands, and the thick layer of tunica muscularis might indicate that camel CUTJP could play a mechanical role in selecting spermatozoa and assisting the hatching of blastocysts during their passage through it.\u003c/p\u003e","manuscriptTitle":"Uterotubal Junction of the Bovine (Bos taurus) vs. the Dromedary Camel (Camelus dromedarius): Histological and Histomorphometry Analysis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-06-05 17:37:17","doi":"10.21203/rs.3.rs-2999187/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"b68e91c4-e62f-4dae-a15b-cfe27966d29c","owner":[],"postedDate":"June 5th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":22038322,"name":"Biological sciences/Biochemistry"},{"id":22038323,"name":"Biological sciences/Evolution"},{"id":22038324,"name":"Biological sciences/Physiology"}],"tags":[],"updatedAt":"2023-09-09T05:44:22+00:00","versionOfRecord":[],"versionCreatedAt":"2023-06-05 17:37:17","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-2999187","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-2999187","identity":"rs-2999187","version":["v1"]},"buildId":"_2-kVJe1T_tPrBINL-cwx","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}