Ovarian gene expression in the absence of FIGLA, an oocyte-specific transcription factor

Ovarian folliculogenesis in mammals is a complex process involving interactions between germ and somatic cells. Carefully orchestrated expression of transcription factors, cell adhesion molecules and growth factors are required for success. We have identified a germ-cell specific, basic helix-loop-helix transcription factor, FIGLA (Factor In the GermLine, Alpha) and demonstrated its involvement in two independent developmental processes: formation of the primordial follicle and coordinate expression of zona pellucida genes.

Taking advantage of Figla null mouse lines, we have used a combined approach of microarray and Serial Analysis of Gene Expression (SAGE) to identify potential downstream target genes. Using high stringent cutoffs, we find that FIGLA functions as a key regulatory molecule in coordinating expression of the NALP family of genes, genes of known oocyte-specific expression and a set of functionally un-annotated genes. FIGLA also inhibits expression of male germ cell specific genes that might otherwise disrupt normal oogenesis.

These data implicate FIGLA as a central regulator of oocyte-specific genes that play roles in folliculogenesis, fertilization and early development.