Exploring the role of endogenous retroviruses in seasonal reproductive cycles: a case study of the ERV-V envelope gene in mink.

Introduction: Endogenous retroviruses (ERVs), which originated from exogenous retroviral infections of germline cells millions of years ago and were inherited by subsequent generations as per Mendelian inheritance patterns, predominantly comprise non-protein-coding sequences due to the accumulation of mutations, insertions, deletions, and truncations. Nevertheless, recent studies have revealed that ERVs play a crucial role in diverse biological processes by encoding various proteins.

Methods: In this study, we successfully identified an ERV envelope ) gene in a mink species. A phylogenetic tree of mink ERV-V and reference sequences was constructed using Bayesian methods and maximum-likelihood inference.

Results: Phylogenetic analyses indicated a significant degree of sequence conservation and positive selection within the -surface open reading frame. Additionally, qRT-PCR revealed diverse patterns of mink ERV-V expression in various tissues. The expression of mink ERV-V gene in testicular tissue strongly correlated with the seasonal reproductive cycles of minks.

Discussion: Our study suggests that the ERV-V gene in mink may have been repurposed for host functions.