Cloning and Identification of Porcine HSPC177 Gene Differentially Expressed in F1, Crossbreds and Their Parents

To investigate the molecular basis of porcine heterosis, suppression subtractive hybridization (SSH) was performed to detect the differences in gene expression between porcine longissirnus dorsi of Meishan × Large White (MS × LW) F, hybrids and their parents Meishan pigs. An expression sequence tag (EST) differentially expressed was found, designated as ML556, which was homologous to a hypothetical protein HSPC117, from human hematopoietic stedprogenitor cells (HSPCs), and the full-length cDNA of porcine HSPC117 was cloned using rapid amplification of cDNA ends (RACE) method. Translation of the mRNA transcript revealed an open reading frame (ORF) of 505 amino acid residues encoding a peroxisomal targeting signal (PTS) with theoretical molecular weight of 55 kDa. Alignment analysis revealed that the deduced protein sequence exhibit 98, 98, 98, 97, and 97% identity with that of cattle, human, dog, rat, and mouse, respectively. The tissue expression analysis indicated that the porcine HSPC117 gene is highly expressed in muscle, spleen, lung, kidney, uterus, ovary and testis, moderately expressed in fat, heart, and liver, and not expressed in stomach and small intestine. The possible role of porcine HSPC117 and its relationship with porcine heterosis were discussed.