Expression of Promyelocytic Leukemia (PML) Protein in the Mouse Developing Spermatogonia

Background: Promyelocytic leukemia (PML) as the main protein of PML nuclear bodies regulates various physiological processes such as transcription, DNA repair, apoptosis, senescence, and several signaling pathways in different cell types. It is well known that the PML protein is involved in the regulation of stem cell properties by maintaining an open chromatin conformation for the regulatory regions of the Oct4 gene. However, there is no experimental evidence for the presence and function of PML protein in the testis tissue. Results: : In this study, we show the presence of PML protein in the developing mouse testis and its co-expression with the OCT4 protein. Immunohistochemical analysis of testis mirror sections shows that PML is co-expressed with the OCT4 protein in the outermost cellular layer of seminiferous tubules, where the spermatogonial stem cells are located. Conclusions: : Our findings suggest that the PML protein might be involved in the stemness of spermatogonial stem cells at different stages of its development, even before earning the ability to produce mature sperm.