Figure 1.

haGSC colonies were derived from enriched spermatogonia and share morphological similarities with early hESC colonies after passaging. Typical representative morphology of spermatogonia and haGSCs from the same patient (157) during culture. (a) Human testis dissociated cells during the first week of culture before selection of spermatogonia. ((b) and (c)) Single, pairs, chains, and groups of round cells with high nucleus/cytoplasm ratio typical of spermatogonia were observable after selection. (d) After 4–6 weeks, some aggregations of the first epithelial haGSCs were observed. (e) Examples of typical early haGSC, (f) early hESC colonies, and (g) typical fibroblasts from testis. Scale bar in ((a)–(c)) 20 μm and ((d)–(g)) 100 μm.