PAILHOUX , Eric

In mammals, sex determination is a process through which the gonad is committed to differentiate into a testis or an ovary. This process relies on a delicate balance between genetic pathways that promote one fate and inhibit the other. Once the gonad is committed to the female pathway, ovarian differentiation begins and, depending on the...

International audience

In vertebrates, 2 main genetic pathways have been shown to regulate ovarian development. Indeed, a loss of function mutations in Rspo1 and Foxl2 promote partial female-to-male sex reversal. In mice, it has been shown that the secreted protein RSPO1 is involved in ovarian differentiation and the transcription factor FOXL2 is required for...

The gonad arises from the thickening of the coelomic epithelium and then commits into the sex determination process. Testis differentiation is activated by the expression of the Y-linked gene Sry, which promotes cell proliferation and differentiation of Sertoli cells, the supporting cells of the testis. In absence of Sry (XX individuals),...

In mammals, the timing of meiosis entry is regulated by signals from the gonadal environment. All-trans retinoic acid (ATRA) signaling is considered the key pathway that promotes Stra8 (stimulated by retinoic acid 8) expression and, in turn, meiosis entry. This model, however, is debated because it is based on analyzing the effects of exogenous...

RSPO1 is a newly discovered gene involved in sex differentiation. Two goat BAC clones encompassing the RSPO1 gene (gRSPO1) were injected into mouse oocytes and several transgenic lines derived. Both clones induced gRSPO1 over-expression in various tissues, including male and female gonads, with no obvious phenotype and normal sex-ratios....

R-spondin1 is a secreted regulator of WNT signaling, involved in both embryonic development and homeostasis of adult organs. It can have a dual role, acting either as a mitogen or as a tumor suppressor. During ovarian development, Rspo1 is a key factor required for sex determination and differentiation of the follicular cell progenitors, but is...