Fig. 2: Knockout of Tmem232 induces male infertility.
From: TMEM232 is required for the formation of sperm flagellum and male fertility in mice
A Schematic of the generation of Tmem232 KO mice using CRISPR-Cas9. Two sgRNAs, sgRNA-1 and sgRNA-2, were constructed to target sequences in introns 4 and 8, respectively. The lower panel shows the location of primers for mouse genotyping at the Tmem232 gene locus and the PCR product size. B Electrophoresis of PCR products amplified from total genomic DNA from the tails of mice with different genotypes (Tmem232+/+, Tmem232+/−, and Tmem232−/−) (left panel). The right panel shows Tmem232 levels in Tmem232+/+ and Tmem232−/− mouse testis. C No significant differences in appearance were observed between Tmem232−/− and wild-type mice. D The average litter size of Tmem232+/+ (n = 6), Tmem232−/− males (n = 6), and Tmem232−/− females (n = 6). Tmem232−/− male and Tmem232−/− female mice were bred with Tmem232+/+ mice, and the average litter size was noted. The Tmem232−/− males were sterile. Tmem232+/+ males (7.00 ± 0.52), Tmem232−/− males (0 ± 0), and Tmem232−/− females (6.50 ± 0.56). Data are presented as mean ± SEM. **** indicates P < 0.0001. NS indicates that the value is not significant. n = 6 for each genotype. E Testis sizes were comparable between Tmem232+/+ and Tmem232−/− mice at 8 weeks of age. F Ratio of testis weight/body weight in Tmem232+/+ and Tmem232−/− male mice at 8 weeks of age. Tmem232+/+ (3.40 ± 0.04 ×10−3), Tmem232−/− (3.33 ± 0.12 ×10−3). Data are presented as the mean ± SEM. NS indicates no significance. n = 6 for each genotype. Representative PAS staining images of testes (G) and caudal epididymis (H) of adult Tmem232+/+, Tmem232+/−, and Tmem232−/− mice. Histomorphology of seminiferous tubules and acrosome morphology in different steps of spermatid development were normal in Tmem232−/− mice. Sperm count in the Tmem232−/− caudal epididymis was lower compared with that of the Tmem232+/+ and Tmem232+/− caudal epididymis. Scale bar: 50 µm. I Fewer sperm were observed in the Tmem232−/− (4.23 ± 0.17) caudal epididymis than that in Tmem232+/+ (7.20 ± 0.13) caudal epididymis. Data are presented as the mean ± SEM. *** indicates P < 0.001. n = 3 for each genotype.
