Tmem203 deficient male mice are infertile
Tmem203 null male and female mice were born at normal Mendelian frequency and showed no gross morphologic alterations, except for a ~10% reduction in weight. While heterozygotes were fully fertile, homozygous mating pairs produced no offspring despite the presence of copulatory plugs. Uninterrupted mating between mice of different genotypes were followed for over a period of 17 weeks (Table 1) to determine if one or both sexes were infertile. The Tmem203 null male mice failed to produce any litter during the duration of the experiments. Female Tmem203 null mice were fertile although the total numbers of litters (12 litters) were lower than that produced by WT or heterozygous females (which produced 22 and 23 litters, respectively).
10.1371/journal.pone.0127480.t001 Table 1  Tmem203 null male mice are sterile.     Uninterrupted mating was performed between sexually mature (aged 8 weeks old) Tmem203 null (tmem203 -/-), heterozygous (tmem203 -/+) and wild type (tmem203 +/+) mice for 17 weeks. All litters and litter sizes were recorded for each mating pair. Tmem203 expression, determined by quantitative real-time PCR from various tissue RNAs, was most abundant in testes (S6 Fig), consistent with a role for Tmem203 in male germ cell development or function. Absolute weight of testes, and mean testes/brain weight ratios at 24-weeks of age were significantly reduced in Tmem203 mutant mice compared to WT littermates (S7 Fig). The prostate gland, seminal vesicles and epididymides appeared normal in Tmem203 null mice by light microscopy (data not shown). Further, the serum levels of Testosterone, follicle stimulating hormone and luteinizing hormone (LH) in wild type and Tmem203 null mice were comparable (data not shown).