Department of Veterinary Anatomy, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
Bioresource Engineering Division, RIKEN BioResouce Research Center, Tsukuba, Ibaraki, Japan.
Nat Commun. 2022 Dec 21;13(1):7860. doi: 10.1038/s41467-022-35465-1.
Seminiferous tubules (STs) in the mammalian testes are connected to the rete testis (RT) via a Sertoli valve (SV). Spermatozoa produced in the STs are released into the tubular luminal fluid and passively transported through the SV into the RT. However, the physiological functions of the RT and SV remain unclear. Here, we identified the expression of Sox17 in RT epithelia. The SV valve was disrupted before puberty in RT-specific Sox17 conditional knockout (Sox17-cKO) male mice. This induced a backflow of RT fluid into the STs, which caused aberrant detachment of immature spermatids. RT of Sox17-cKO mice had reduced expression levels of various growth factor genes, which presumably support SV formation. When transplanted next to the Sox17 RT, Sertoli cells of Sox17-cKO mice reconstructed the SV and supported proper spermiogenesis in the STs. This study highlights the novel and unexpected modulatory roles of the RT in SV valve formation and spermatogenesis in mouse testes, as a downstream action of Sox17.
哺乳动物睾丸的生精小管(STs)通过支持细胞管腔连接(SV)与睾丸网(RT)相连。在 ST 中产生的精子被释放到管腔液中,并通过 SV 被动运输到 RT。然而,RT 和 SV 的生理功能仍不清楚。在这里,我们鉴定了 Sox17 在 RT 上皮中的表达。在青春期前,RT 特异性 Sox17 条件性敲除(Sox17-cKO)雄性小鼠的 SV 阀被破坏。这导致 RT 中的液体回流到 ST,导致未成熟精子细胞异常脱落。Sox17-cKO 小鼠的 RT 表达各种生长因子基因的水平降低,这些基因可能支持 SV 的形成。当与 Sox17 RT 相邻移植时,Sox17-cKO 小鼠的支持细胞重建了 SV,并在 ST 中支持适当的精子发生。这项研究强调了 Sox17 作为下游作用,在 SV 阀形成和小鼠睾丸精子发生中,RT 具有新的和意外的调节作用。