NOBOX Oogenesis Homeobox Protein (NOBOX)

NOBOX is a homeobox gene that is preferentially expressed in oocytes. In mice, it is essential for folliculogenesis and regulation of oocyte-specific genes.The mouse and human proteins share 92% identity in the homeodomain region. RT-PCR and Northern blot analyses of mouse tissues detected Nobox expression only in testis and ovary. In situ hybridization of mouse ovaries revealed Nobox mRNA in primordial and growing oocytes.The deduced protein contains a homeodomain that includes a nuclear localization signal. Nested PCR detected NOBOX expression in ovary, testis, and pancreas. NOBOX was expressed from the primordial follicle stage through to the metaphase II oocytes. Expression was lower in preimplantation embryos and was not observed in granulosa cells.