GNRH1 and Infertility: Because humans with GNRH1 mutations [17], hpg mutant mice [15], and Gnrh3 cell-ablated zebrafish [12] are all infertile individuals with arrested gonad development, we hypothesized that knocking out the gnrh3 gene in zebrafish would also lead to disrupted gametogenesis and the production of infertile fish.