Abstract:

【Objective】 Extracellular signal-regulated kinase-2 (ERK2) gene plays important roles in regulating cell proliferation and differentiation, as well as starting the ovulation of ovary. It is an important candidate gene for porcine reproduction traits. In this study, the pig ERK2 gene was cloned and its genomic organization, tissue expression patterns, and gene polymorphism were investigated.【Method】 In this study, the pig ERK2 gene was cloned by RT-PCR and its mRNA distribution in different tissues was studied by real time PCR, moreover, the ERK2 gene structure and polymorphisms were analyzed. 【Result】 The cloned pig ERK2 cDNA was 1 888 bp long, and contained an open reading frame of 1 080 bp, which encoded a peptide of 359 amino acid residues. The encoded ERK2 was highly similar with predicted pig ERK2 and the human and mouse counterpart. The ERK2 gene was widely expressed in many porcine tissues. The highest expression was found in spleen, however almost no expression in adipose tissue, muscle tissues from front and back legs. The pig ERK2 gene was located at the 14th chromosome, and composed of 9 exons and 8 introns. Variation detection of exon 2-9 and intron-exon boundary sequences indicated that a total of 11 SNPs and 1 indel were identified, most of which were in introns and only one was in 3’ UTR. 【Conclusion】The obtained cDNA of pig ERK2 gene was 1 888 bp long and encoded a 359-amino acid peptide. The ERK2 gene was found to express in many tissues of pig with highest level in spleen. The ERK2 gene comprised 9 exons and 8 introns and showed high conservation. A total of 11 SNP and 1 indel were found, but none of them was in coding regions.

Key words: pig, ERK2 gene, cDNA cloning, tissue expression, SNP