Figure 4. Transit amplifying A_undiff chain length and numbers are reduced in Lin28a mutant mice.

(A) Quantification of PLZF positive cells on histological cross sections of adult testis detected by immunofluorescence in epithelial stages VI and VII. PLZF positive cells were reduced in mutants when normalized by Sertoli cell number. (B) Images representative of the criteria for identifying GFRα1 positive A_s/A_pr spermatogonia in stages IX (post sperm release front, indicated with a black arrow) and the SOHLH1 positive A_al-4, A_al-8, and A_al-16 cells in stages VI and VII (pre-sperm release front) on whole mount seminiferous tubules isolated from adult mice. (C) Plot shows no change in number of GFRα1 positive A_s/A_pr spermatogonia in epithelial stages IX (as depicted in B) when comparing control and Lin28a mutant samples. (D) Plot shows significant changes in number of SOHLH1 positive chains in epithelial stages VII and VIII (as depicted in B) when comparing control and Lin28a mutant samples. (n=5). Values represent the mean ± SEM. * Indicates P≤0.01. Scale bar = 20 um.