FOXL2 is a female sex-determining gene in the goat

Remerciements aux membres de l'Unité Commune d’Expérimentation Animale, spécialement Céleste Le Bourhis, Valérie Hallé, Jean-Pierre Albert, Didier Mauchand, Jean-François Alkombre, Jean- Michel Bastard, et Aurélie Brun, for goat management (breeding, embryo transfers, euthanasia, surgery, anesthesia, and ultrasound scanning). Remerciements à Ikrame Naciri, Dominique Thépot, Sylvie Ruffini, Ludivine Laffont, Linda Maulny et Stephan Bouet for their helpful technical assistance. We also thank Alan Conley (University of California) for the anti-CYP17 anti- body.International audienceThe origin of sex reversal in XX goats homozygous for the polled intersex syndrome (PIS) mutation was unclear because of the complexity of the mutation that affects the transcription of both FOXL2 and several long noncoding RNAs (lncRNAs) [1, 2]. Accumulating evidence suggested that FOXL2 could be the sole gene of the PIS locus responsible for XX sex reversal, the lncRNAs being involved in transcriptional regulation of FOXL2 [2]. In this study, using zinc-finger nuclease-directed mutagenesis, we generated several fetuses, of which one XX individual bears biallelic mutations of FOXL2. Our analysis demonstrates that FOXL2 loss of function dissociated from loss of lncRNA expression is sufficient to cause an XX female-to-male sex reversal in the goat model and, as in the mouse model, an agenesis of eyelids. Both developmental defects were reproduced in two newborn animals cloned from the XX FOXL2(-/-) fibroblasts. These results therefore identify FOXL2 as a bona fide female sex-determining gene in the goat. They also highlight a stage-dependent role of FOXL2 in the ovary, different between goats and mice, being important for fetal development in the former but for postnatal maintenance in the latter