Fig. 2.

Functional distinction of ID4-EGFP⁺ spermatogonial subsets by transplantation. (A) Experimental scheme to assess regenerative capacity of ID4-EGFP^Bright and ID4-EGFP^Dim spermatogonial subsets by transplantation analyses. (B) Representative images of recipient testes transplanted with 1×10⁴ ID4-EGFP^Bright or ID4-EGFP^Dim cells. Each blue segment is a colony of spermatogenesis derived from an individual transplanted donor SSC. (C) Quantitative comparison of donor-derived spermatogenic colonies derived from transplantation of ID4-EGFP^Bright or ID4-EGFP^Dim spermatogonia (1×10⁴ cells transplanted/recipient testis). Data are mean±s.e.m. and n=3 different cell preparations and 29 recipient testes. *P<0.05. (D) Representative images of recipient testes transplanted with 1000, 100 or 10 ID4-EGFP^Bright spermatogonia.