Fig. 4.
GnrhrE90K homozygous males exhibit normal testis histology despite reduced testis size. A and B, Wild-type (A) and E90K/+ (B) testes were indistinguishable in size, abundance of eosin-stained Leydig cells (arrows), and presence of spermatozoa in the seminiferous tubules (arrowheads). C, Testes from E90K homozygotes were smaller but still displayed abundant Leydig cells (arrow) and spermatozoa (arrowhead), indicating normal function. D, For comparison, L117P homozygotes exhibit extremely small testes, lack of eosin-stained Leydig cells (arrow), and spermatogenic arrest at the round spermatid stage (arrowhead). On the left are stereomicroscope images. Scale bar, 2 mm. Center and right columns show hematoxylin- and eosin-stained sections. Scale bar, 0.1 mm. E, Differences in testis weight between genotypes were quantitated by weighing them as a pair. No difference was found between wild-type and E90K heterozygotes, whereas the testes of E90K homozygotes were smaller. L117P homozygotes, which cannot complete spermatogenesis, exhibited the lowest testis weight of any genotype. Significant differences are denoted by the lowercase letters above each bar. Equivalent means have the same letter; different letters indicate statistically significant differences (P < 0.05). Error bars represent sem.