Magnetic activated cell sorting allows isolation of spermatogonia from adult primate testes and reveals distinct GFRa1‐positive subpopulations in men

BACKGROUND: Isolation of spermatogonial stem cells (SSCs) could enable in vitro approaches for exploration of spermatogonial physiology and therapeutic approaches for fertility preservation. SSC isolation from adult testes is difficult due to low cell numbers and lacking cell surface markers. Glial cell-derived neurotrophic factor family receptor alpha-1 (GFRalpha1) plays a crucial role for the maintenance of SSCs in rodents and is expressed in monkey spermatogonia. METHODS: Magnetic activated cell sorting was employed for the enrichment of GFRalpha1+ spermatogonia from adult primate testes. RESULTS: Magnetic activated cell sorting of monkey cells enriched GFRalpha1+ cells threefold. 11.4% of GFRalpha1+ cells were recovered. 42.9% of GFRalpha1+ cells were recovered in sorted fractions of human testicular cells, representing a fivefold enrichment. Interestingly, a high degree of morphological heterogeneity among the GFRalpha1+ cells from human testes was observed. CONCLUSIONS: Magnetic activated cell sorting using anti-GFRalpha1 antibodies provides an enrichment strategy for spermatogonia from monkey and human testes.