Quantification of the delay of the first wave of spermatogenesis. A
, For each mouse, we analysed 300 seminiferous tubules in 15 testis sections. We classified each tubule according to the most differentiated germ cells that it contained (ZS, Zygotene Spermatocyte; PS, Pachytene Spermatocyte; RS, Round Spermatid; ES, Elongated Spermatid; Spz, Spermatozoa). Next, we calculated for each mouse the percentage of seminiferous tubules of each class, and we plotted the percentage of seminiferous tubules of the most advanced class against the age. Blue diamonds and orange squares correspond to individual Celf1+/+ and Celf1−/− mice respectively. B, We quantified by real-time RT-PCR the relative amounts of the indicated mRNAs (Mouse Vasa Homolog, Ddx4; Proacrosine, Acr; Heat Shock Protein 70.2, Hspa2; Lactate Dehydrogenase 3, Ldhc; Miwi, Piwil1) for +/+ and −/− testes of similar stages of spermatogenesis but different ages: lower panels and inserts, 17 dpp +/+ (blue bars) and 24 dpp −/− (orange bars) testes with 20% of seminiferous tubules of the PS class; upper panels, 24 dpp +/+ (blue bars) and 42 dpp −/− (orange bars) testes with 60% of seminiferous tubules of the RS class. Results are expressed as the means of 3–5 animals for each genotype. Error bars are standard deviations. We used a Student’s t-test to statistically compare the +/+ and the −/− genotypes, and the p-values below 0.1 are given on the right of the corresponding bars.