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.

哺乳动物睾丸中的曲细精管 (ST) 通过支持阀 (SV) 连接到睾丸网 (RT)。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 中。然而，RT 和 SV 的生理功能仍不清楚。在这里，我们确定了Sox17在 RT 上皮细胞中的表达。在 RT 特异性Sox17条件性敲除 ( Sox17- cKO ) 雄性小鼠的青春期前，SV 阀被破坏。这导致 RT 液体回流到 ST，导致未成熟精子细胞异常脱离。Sox17-cKO小鼠的 RT降低了各种生长因子基因的表达水平，这可能支持 SV 的形成。移植到旁边时Sox17 ⁺ RT，Sox17-cKO 小鼠的支持细胞重建SV 并支持 ST 中的正确精子发生。这项研究强调了 RT 在小鼠睾丸 SV 瓣膜形成和精子发生中的新颖和意想不到的调节作用，作为Sox17的下游作用。