Cloning and characterization of porcine NOBOX gene

Newborn ovary homeobox gene (NOBOX) is an oocyte-specific homeobox gene that plays a critical role in early folliculogenesis and represents a candidate gene for nonsyndromic ovarian failure. We used in silico approach in combination with rapid amplification of cDNA ends (RACE) to clone the full-length cDNA of NOBOX (GenBank Accession No. FJ587509) from porcine oocytes. It contains 1768 bp nucleotides, with an open reading frame (ORF) of 1419 bp. The putative porcine NOBOX gene encodes 472 amino acids with the molecular weight of 51.08 kD and pI of 5.73. Bioinformatics prediction indicates that this protein contains a cd00086 homeodomain. Real-time PCR analysis showed that the NOBOX gene is expressed in various tissues, oocytes and embryos cells (4-cell, 8-cell, morula and blastocyst) at different expression levels. The expression levels of this gene in heart, kidney and oocytes are higher than that in other tissues, which suggested that the NOBOX protein might play an important role in those tissues. The expression of NOBOX in developmental stages is higher than that in GV-stage oocytes, which suggested that the expression of pNOBOX was enhanced in developmental stages.