FIG. 4.

Effects of impaired STAT3 expression on re-establishment of spermatogenesis following spermatogonial transplantation. A) Schematic of the experimental strategy to examine the effects of impaired STAT3 expression on spermatogonial activity in vivo. B) Quantitative RT-PCR analysis of Stat3 gene expression in cultured THY1⁺ germ cells stably transduced with control or Stat3 shRNA lentivirus. C) Representative image of a recipient mouse seminiferous tubule transplanted with cultured THY1⁺ ROSA germ cells transduced with nontargeting control shRNA lentivirus. Densely blue-stained colonies (arrow) indicate complete spermatogenesis derived from an injected SSC. D–F) Representative images of recipient mouse seminiferous tubules transplanted with cultured THY1⁺ ROSA germ cells transduced with Stat3 shRNA lentivirus. Colonies ranging from a single cell (asterisks) to chains of spermatogonia (arrows) were observed, but no densely stained colonies were identified. Chains of spermatogonia no greater than 16 cells were observed. These observations indicate impaired differentiation of A_s and A_pr/A_al spermatogonia. Bars = 2 mm (C and D) and 0.5 mm (E and F).