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.
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.
基金
supported by the National Key Research and Development Program of China (2017YFA0102801 and 2017YFC1001901)
the Science and Technology Planning Project of Guangdong Province (2015B020228002)
the National Natural Science Foundation of China (31671540)
the Natural Science Foundation of Guangdong Province (2015A020212005 and 2014A030312011)
the Guangzhou Science and Technology Project (201803010020)
