A novel undifferentiated spermatogonia-specific surface protein 1 (USSP1) in neonatal mice

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2019,（8）
• 页码范围: 524-533
• 页数: 10页
• 语种: 英文

摘要

Mammalian spermatogenesis is maintained by a rare population of spermatogonial stem cells (SSCs), which are important for male fertility. SSCs remain a subset of undifferentiated spermatogonia, which can be isolated by a combination of surface markers. Specific markers to identify and isolate undifferentiated spermatogonia are lacking. Ussp1, a transcript previously annotated as long noncoding RNA (RIKEN cDNA 4933427D06, Gene ID: 232217), virtually encodes a membrane protein, USSP1, in a highly testisspecific manner in mouse. We demonstrate its expression on the membrane of undifferentiated spermatogonia by a homemade polyclonal rabbit antibody against the protein. In vivo, USSP1+ clusters consist mainly of As, Apr (GFRa1+) and Aal (PLZF+) cells. USSP1+ cells exhibit enrichment of undifferentiated spermatogonia, as shown by increased expression of SSC self-renewal molecular markers and the potential to form SSC clones in vitro and in vivo. However, Ussp1 knockout did not affect the number of SSCs or spermatogenesis in mice. Thy1+ cells from Ussp1 null mice did not show any defect in the SSC colony formation capacity, indicating that USSP1 is not essential for SSC self-renewal. Our data demonstrate that Ussp1 is specifically expressed in undifferentiated murine spermatogonia, indicating the potential to sort undifferentiated spermatogonia with USSP1 antibodies. Ussp1 might be a good maker for SSC enrichment in neonatal mice.