Association of porcine <I>ATF4</I> gene polymorphism and pro-duction traits and analysis of gene expression

Abstract

In order to understand the function of gene ATF4 and identify new DNA markers involved in pig production traits, the cDNA fragment of porcine ATF4 was cloned and sequenced. Sequence comparison revealed an A159G substitution downstream of the initiation codon (ATG). We then carried out PCR-AluⅠ-RFLP analysis in Large white, Landrace, Tongcheng and Meishan pigs, followed by association analysis in F2 "Large white ×Meishan" resource family. In all the individuals tested, Large White and Landrace pigs possessed the AA genotype, while Meishan and Tongcheng pigs pos-sessed the GG genotype. Association analysis in F2 resource family showed that this site was highly associated with buttock fat thickness (BFT) (Pamp;0.01) and had significant effect on thorax-waist fat thickness (TFT), average backfat thickness (ABT), loin eye height (LEH), and loin eye area (LEA)(Pamp;0.05). Real-time PCR was used to analyze the expression patterns of porcine ATF4 gene in longissimus dorsi at different development stages of Large White and Meishan pigs. The results showed that the gene expression levels of ATF4 were low 65 days after conception and 3 days after birth, but no signifi-cant differences were observed in both breeds. Meanwhile, the expression levels of porcine ATF4 gene were up-regulated 60 days and 120 days after birth in both breeds and the expression level in Meishan pigs was obviously higher than that in Large White pigs. These data could lay the foundation for further study on the molecular mechanism of porcine ATF4 gene in lipid metabolism.