Species: mouse
Mutation name: None
type: null mutation
fertility: infertile - ovarian defect
Comment: Soyal SM, et al 2000 reported that FIG alpha, a germ cell-specific transcription factor, is required for ovarian follicle formation. Primordial follicles are formed perinatally in mammalian ovaries and at birth represent the lifetime complement of germ cells. FIG alpha, a transcription factor implicated in postnatal oocyte-specific gene expression, is detected as early as embryonic day 13, Mouse lines lacking FIG alpha were established by targeted mutagenesis in embryonic stem cells. Although embryonic gonadogenesis appeared normal, primordial follicles were not formed at birth, and massive depletion of oocytes resulted in shrunken ovaries and female sterility. Fig alpha (the gene for FIG alpha) null males have normal fertility. The additional observation that null females do not express Zp1, Zp2 or Zp3 indicates that FIG alpha plays a key regulatory role in the expression of multiple oocyte-specific genes, including those that initiate folliculogenesis and those that encode the zona pellucida required for fertilization and early embryonic survival. The persistence of FIG alpha in adult females suggests that it may regulate additional pathways that are essential for normal ovarian development.