FIMP1 and Infertility: The infertile phenotype of Fimp KO males was fully rescued by the transgene (8.6 ± 3.0, 0.4 ± 0.9, and 7.1 ± 2.2 pups per plug in the wild-type [12 plugs], Fimp KO [15 plugs], and Tg rescued Fimp KO [23 plugs] males, respectively; P < 0.01; Fig. 4C).