Figure 3.

Meiotic, not mitotic, activity of spermatogenesis declines rapidly in young adult male C. elegans. (a) Anatomy of the C. elegans male testis and germ cell nuclei morphology. Right panel, DIC image of an intact testis isolated from a D2 N2adult male worm. Left panel, nuclei visualized by Hoechst 33342 staining. Regions of the testis are indicated. (b) Left panel, EdU incorporation rate in testes of N2 adult male worms of different ages maintained at 22°C. More than 50 testes from each age‐group were examined for the presence of EdU signal after labeling for 24 hr. Right panel, fluorescent images of EdU‐labeled and Hoechst 333‐stained testes. Arrow indicates EdU‐labeled nuclei. (c) Right panel, meiotic division activity in the testes of N2 adult male worms of different ages maintained at 22°C. More than 50 testes from each age‐group were analyzed. Left panel, immunofluorescent staining of meiotic α‐tubulin in testes of D2 and D5 N2 adult males. Arrow indicates an α‐tubulin spindle