Molecular characterization and chromosomal mapping of the porcine AMP-activated protein kinase α2 (PRKAA2) gene

Abstract

AMP-activated protein kinase alpha 2 (PRKAA2) plays a key role in regulation of fatty acid and cholesterol metabolism. This study investigated the porcine PRKAA2 gene as a positional candidate for intramuscular fat and backfat thickness traits in pig chromosome 6. A partial fragment of the porcine PRKAA2 gene, amplified by PCR, contained a putative intron 3 including a part of exon 3 and 4, comparable with that of human PRKAA2 gene. Within the fragment, several single nucleotide polymorphisms were identified using multiple sequence alignments. Of these, TaqI restriction enzyme polymorphism was used for genotyping various pig breeds including Korean reference family. Using linkage and physical mapping, the porcine PRKAA2 gene was mapped in the region between microsatellite markers SW1881 and SW1680 on chromosome 6. Allele frequencies were quite different among pig breeds. The full length cDNA of the porcine PRKAA2 (2,145 bp) obtained by RACE containing 1,656 bp open reading frame of deduced 552 amino acids, had sequence identities with PRKAA2 of human (98.2%), rat (97.8%), and mouse (97.5%). These results suggested that the porcine PRKAA2 is a positional candidate gene for fat deposition trait at near telomeric region of the long arm of SSC 6.