Identification and sequence analysis of the B2L and F1L genes of the ORFV isolated in Yunnan: epidemiological and evolutionary insights

The primary focus of this investigation was the meticulous examination of the genetic composition and protein structure of the B2L and F1L genes. Notably, specimens were meticulously procured from the oral cavities of infected goats. Subsequent to verification through polymerase chain reaction (PCR), the virus was successfully cultured in goat testis cells. The designated ORFV strains were denoted as ORFV/goat/YNSLi/China/2021/Yunnan,ORFV/goat/YNSLi/China/2023/Yunnan,ORFV/goat/YNYLn/China/2022/Yunnan,and ORFV/goat/YNTJe/China/2023/Yunnan. The genetic data pertaining to the core genes (B2L, F1L) were meticulously scrutinized to elucidate their epidemiological and evolutionary attributes. Analysis of the B2L gene sequences revealed that all four strains were classified within cluster I of group I, with discernible variations in sequences across the temporal spectrum. Conversely, inspection of the F1L gene sequences unveiled that YNSLi/2023 and YNTJe/2023 were positioned in cluster I of group I, YNSLi/2021 resided in cluster III of group I, and YNYLn/2022 was allocated to cluster IV. The distinctive Yunnan ORFV strains exhibited noteworthy characteristics, including gene rearrangements during the outbreak. Examination of the protein structures showcased variances in hydrophobicity and stability in comparison to other strains. While similarities were noted in hydrophilic flexibility, antigenic index, and surface accessibility, discrepancies in amino acids were observed to influence protein structure. Projections derived from the analysis of the B2L and F1L genes suggested the absence of signal peptides and transmembrane domains. This comprehensive study contributes significantly to the comprehension of ORFV transmission and evolution, thereby furnishing invaluable insights for the formulation of preventive and control strategies within Yunnan Province.