Fig. 1: PARL deficiency leads to a reduction in testis weight and morphological degradation.
From: The mitochondrial protease PARL is required for spermatogenesis
a Testes of 8-week-old wild-type (WT) and PARL-deficient (Parl−/−) mice. b Average weight of both testes of 4-week- (4 W) and 8-week- (8 W) old mice with the indicated genotype. (4 W: WT: n = 3, Parl−/−: n = 5; 8 W: WT: n = 9, +/−: n = 5, −/−: n = 10; Error bars indicate standard deviation. Statistics: 4 W: Mann–Whitney U test: p = 0.0357, 8 W: Kolmogorov–Smirnov test p > 0.1000 for all groups, one-way ANOVA: p < 0.0001). c Average diameter of the seminiferous tubules of 8-week-old Parl−/− mice in comparison to their WT litter mates. The average diameter of 10 tubules was taken for 8 animals (n = 8). (Error bars indicate standard deviation. Statistics: Kolmogorov–Smirnov test: WT: p = 0.0893, Parl−/−: p > 0.1000, unpaired two-tailed t test: p < 0.0001). d Scanning electron microscopy (SEM) pictures of seminiferous tubules of 8-week-old WT and Parl−/− mice (scale bars; left: 50 µm, right: 10 µm). e Semi-thin sections of WT and Parl−/− testes stained with toluidine blue at the age of 4 weeks and 8 weeks (scale bar: 25 µm). f Higher magnification of multinucleated giant cells in semi-thin sections and in immunohistological fluorescence staining (SDHA, nuclei were counterstained with bisbenzimide (blue)) of Parl−/− mice at 4 and 8 weeks (scale bars: 10 µm). Arrows in (e) and (f) indicate lipid droplets within the seminiferous tubule and within the giant cells. g Transmission electron microscopy (TEM) pictures of spermatocytes of 4-week- and 8-week-old WT and Parl−/− mice. Asterisks indicate vacuoles, and the arrow indicates a lipid droplet (scale bar: 2 µm).
