Too making good knowledge about the SSCs I suggest you to read some articles about this toipic such as "Spermatogonial stem cells: unlimited potential, Dym et al., Reproduction, Fertility and Development, 2009 "
Thanks for your suggestion. I reviewed many article about this topic. Articles usually suggest a pool of markers to identify SSCs but I can't find a specific marker which is only express in SSCs.
While there is no specific marker for SSCs, there are a few that have been described in undifferentiated spermatogonia (As, Apr, and Aal) that can be useful when it comes to define presence of SSCs (Ngn3, PLZF, Oct4, nanog, GFRa1, Sox3). Also, absence of c-kit in SSC has also been described.
Similar to other tissue specific stem cells, a "true" maker is very hard to find. SSCs are defined by their ability to make regenerative colonies after transplantation or lineage tracing. It is known for years that SSC activities reside in the undifferentiated population, which can be marked by Plzf, Sall4, Lin28, Sox3. It is further proposed that SSCs are greatly enriched in As and Apr population, which can be identified by Id4 and likely Utf1. These are intracellular proteins. For surface markers, GFRa1 is expressed in As, Apr and short chains of Aal spermatogonia and it can be used to enrich SSCs. Another marker is Thy1. Thy1+ spermatogonia contain SSCs, although a Thy1+ testis cell population also contains somatic cells.