Identification of a promoter polymorphism affecting gene expression that is likely related to intramuscular fat content in pigs.

The intramuscular fat content (IMF) is an economically important trait in pigs and the Laiwu pig is famous for its excessively extremely high level of IMF. Our previous transcriptome study revealed that the dynamic expression of glycerol-phosphate acyltransferase 3 () is consistent with changes in the IMF of Laiwu pigs. In this study, we further analyzed the expression and polymorphism of in its promoter region. The results indicated that the expression of increased dramatically from 120 to 240 days and is consistent with changes in IMF deposition, and at both mRNA and protein levels, expression was markedly higher in the LD muscle of Laiwu pigs than that of Duroc × Landrace × Yorkshire pigs. Deletion from -1695 to -1187 of porcine greatly increased its transcription. Of the two SNPs identified, the transition from to at -1526 site increased the transcription of porcine and allele mainly distributed in Laiwu pig population. These results collectively suggest that the SNP at -1526 site of may contribute to IMF deposition by affecting its expression in pigs.