SOX17-positive rete testis epithelium is required for Sertoli valve formation and normal spermiogenesis in the male mouse

• Published in: Nature communications Vol. 13; no. 1; p. 7860
• Main Authors: Uchida, Aya, Imaimatsu, Kenya, Suzuki, Honoka, Han, Xiao, Ushioda, Hiroki, Uemura, Mami, Imura-Kishi, Kasane, Hiramatsu, Ryuji, Takase, Hinako M., Hirate, Yoshikazu, Ogura, Atsuo, Kanai-Azuma, Masami, Kudo, Akihiko, Kanai, Yoshiakira
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 21-12-2022; Nature Publishing Group; Nature Portfolio
• Subjects: 13; 13/51; 14; 14/1; 14/19; 147/143; 38; 38/91; 631/136/1660; 631/443/494; 692/698/1864; Animals; Epithelium; Fluid dynamics; Fluid flow; Growth factors; HMGB Proteins - metabolism; Humanities and Social Sciences; Male; Males; Mammals; Mice; Mice, Knockout; multidisciplinary; Puberty; Rete Testis - metabolism; Science; Science (multidisciplinary); Sertoli cells; Sertoli Cells - metabolism; Sexual Maturation; SOXF Transcription Factors - genetics; SOXF Transcription Factors - metabolism; Spermatids; Spermatogenesis; Spermatogenesis - genetics; Spermatozoa; Spermiogenesis; Testes; Testis - metabolism; Tubules
• ISSN: 2041-1723; 2041-1723
• 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
.
A valve-like structure called this Sertoli valve (SV) supports spermatogenesis by modulating the directional fluid flow in mouse testis. The SV formation is supported by its neighboring SOX17 + rete testis (RT). This study highlights the essential roles of RT and SV in spermatogenesis.