Fertility of wild-type (Sec46Ala−/−) and heterozygous Gpx4 knock-in mice (Sec46Ala-Gpx4+/−) and motility of sperm extracted from the epididymal cauda.
A, male and female individuals of different genotype were mated, and the sizes of the different litters (number of newborns) were quantified. Because of the early lethality of homozygous Gpx4 Sec46Ala knock-in embryos, the litter sizes (number of embryos) were corrected according to Mendelian genetics. Stars indicate significant (p < 0.05) differences between the experimental groups. Sec46Ala−/− × Sec46Ala−/−: 36 matings with 269 newborns; Sec46Ala+/−
x Sec46Ala+/−: 9 matings with 35 newborns, 47 (Mendel's law); Sec46Ala−/− (males) × Sec46Ala+/− (females): 18 matings with 115 newborns, Sec46Ala+/− (males) × Sec46Ala−/− (females): 50 matings, 257 newborns. B, sperm extracted from the epididymal cauda were analyzed for their motility characteristics using a computer-assisted system (see “Materials and Methods”). According to their motility, sperm were classified into 3 groups: I, motile sperm; II, sperm with progressive movement (slow and rapid forward movement, circular movement); III, sperm with rapid forward movement. For each genotype, five mice were included in the motility analyses. C, sperm were extracted from the epididymal cauda of male Sec46Ala-Gpx4+/− mice and were genotyped by allele specific genomic PCR as described under “Materials and Methods.” U46A represents Sec46Ala exchange. M, mass markers. o, outlier.