Cell adhesion function was altered during the seasonal regression of the seminiferous epithelium in the mink species Neovison vison

Abstract

Minks are seasonal breeders whose seminiferous epithelium undergoes regression through massive germ cell death, leaving only Sertoli cells and spermatogonial cells in the tubules. However, the molecular mechanisms that control this biological process remain largely unknown. This study describes a transcriptomic analysis of mink testes at various reproductive stages (active, regressing, and inactive). A comparison of seminiferous epithelium at different stages of reproduction shows that cell adhesion is altered during regression. In addition, genes and proteins involved in forming the blood-testis barrier (BTB) were examined in sexually active and inactive minks. The seminiferous epithelium in the testes of sexually inactive minks expressed occludin, but this expression was not discernibly observed in the testes of sexually active minks. There was no discernible expression of CX43 in the seminiferous epithelium in the testes of sexually inactive minks, but CX43 was expressed in the testes of sexually active minks. During the regression process, we observed a remarkable increase in the expression levels of Claudin-11, which is associated with Sertoli-germ cell junctions. In conclusion, these findings suggest a loss of Sertoli-germ cell adhesion, which may regulate postmeiotic cell shedding during testicular regression in mink.

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

“…The Institutional Animal Care and Use Committee of the Chinese Academy of Agricultural Sciences in Jilin Province, China, reviewed and approved the protocol for animal experiments (Approval number: 2020007) ( Zhang et al., 2023 ). The experiments were conducted in collaboration by the Institute of Special Animal and Plant Sciences, the Chinese Academy of Agricultural Sciences, and Inner Mongolia Agricultural University.…”

“…Male black minks ( Neovison vison ) that were eleven months old were obtained from the research facility at the Chinese Academy of Agricultural Sciences. Each mink was kept in its own cage, given a daily portion of commercial food, exposed to sunlight, and allowed to freely eat and drink ( Zhang and Xu, 2022 ; Zhang et al., 2023 ).…”

“…Black mink testes were collected in January (n = 6), February (n = 6), March (n = 6), April (n = 6), May (n = 6), June (n = 6), July (n = 6), August (n = 6), September (n = 6), October (n = 6), November (n = 6), and December (n = 6). The minks used in this experiment were identical to those in Zhang and Xu, 2022 and Zhang et al., 2023 .…”

“…The RT-PCR primers used were env -F (5’- TAGGAGAGCTCTTGGGCGTT-3’) and env -R (5’-TCCTGGCGGCTCTCTAAACT-3’). Relative expression of the selected genes was adjusted using GAPDH as an endogenous control ( Zhang et al., 2023 ). The study employed the comparative cycle threshold method to determine the amplification fold, with the cycle threshold (Ct) representing the number of PCR cycles needed to reach the fluorescence threshold.…”

“…Thus, they are valuable subjects for investigating the fundamental mechanisms governing spermatogenesis ( Blottner et al., 2006 ; Pelletier et al., 2015 ). The circannual cycle of minks encompasses three primary stages of testicular function—(i) reactivation of testicular activity in autumn (November), (ii) peak sexual activity (February to March), and (iii) sexual inactivity (May to October) ( Zhang et al., 2023 ).…”