spermatogonium adult stem cell type A spermatogonium 2020-03-29T16:33:37Z BTO:0006348 BrendaTissueOBO Germ stem cells of the seminiferous epithelium in the testis. A spermatogonium that does not differentiate into a spermatocyte, a precursor of sperm cells. Instead, they continue dividing into other spermatogonia or remain dormant to maintain a reserve of spermatogonia. Type B spermatogonia, on the other hand, differentiate into spermatocytes, which in turn undergo meiosis to eventually form mature sperm cells. Marion SSC cell spermatogonial stem cell