Molecular characterization and expression profile of a novel porcine gene differentially expressed in the muscle tissues from Meishan, Large White and their hybrids.

In order to detect the molecular mechanism of heterosis in pigs, the mRNA differential display technique was performed to investigate the differences in gene expression in the longissimus dorsi muscle tissues from Meishan, Meishan x Large White cross and Large White pigs. One novel gene that was differentially expressed was identified using semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and its full-length cDNA sequence was obtained using the rapid amplification of cDNA ends (RACE) method. The nucleotide sequence of the gene is not homologous to any of the known porcine genes. Sequence analysis revealed that open reading frame of this gene encoding a protein of 105 amid acids and this protein showed 100% homology to bovine and ovine CYCS, and therefore, this gene can be defined as the swine CYCS gene. The genomic sequence of swine CYCS gene was finally amplified and result revealed that the swine CYCS gene contains no introns. Tissue expression profile analysis revealed that swine CYCS gene was highly expressed in muscle, fat and lung, moderately expressed in ovary, kidney, and liver, and weekly expressed in heart, spleen and small intestine. Our results established the primary foundation for further research into the biological significance of swine CYCS gene.