Sequencing, Polymorphism and Expression Profile Analysis of Porcine Hexokinase II (HK2) Gene

Hexokinase II has been demonstrated to play the role of a key enzyme member in the glycolysis reaction. It catalyzes the conversion of glucose to glucose-6-phosphate, thus committing glucose to the glycolytic pathway. In this paper, the partial exons and introns 10, 11, 13 and 14 of the porcine HK2 gene were cloned and sequenced by comparative genomics. Comparative sequencing of three pig breeds revealed ten putative single-nucleotide polymorphisms (SNPs), one of which in intron 10 with differing bases (G981A) is within the restriction site for enzyme Msp I. Distribution of Msp I -RFLP genotype and allele frequencies among different pig breeds were studied. By association analysis between Msp I PCR-RFLP polymorphism (AA, AB, BB genotypes of HK2 gene intron 10) and some meat quality and carcass traits in F2 group, which was constructed by our laboratory, a significant difference of pig average backfat at rump was found between AB and BB genotypes (P<0 05) in F2 group. In addition, the pattern of expression of HK2 in a variety of tissues in pig was also determined using semi-quantitative RT-PCR. The expression of HK2 mRNA was detected only in pig skeletal muscle.