Insertion of 643bp Retrotransposon Upstream of <i>PPARγ</i> CDS Is Associated with Backfat of Large White Pigs

Abstract

PPARs are essential regulators of mammalian fatty acid and lipid metabolism. Although the effects of genetic variations, including single nucleotide polymorphisms (SNPs) in PPARs genes on the phenotype of domestic animals have been investigated, there is limited information on the impact of retrotransposon insertion polymorphisms (RIPs). In this study, a combined comparative genome and polymerase chain reaction (PCR) was used to excavate the RIPs in porcine PPARs. We also investigated the potential effects of retrotransposon insertion on phenotype and expression patterns. This study identified the two RIPs in PPARs genes, namely an ERV in intron 1 of PPARα and a combined retrotransposon in intron 2 of PPARγ, designated as PPARα-ERV-RIP and PPARγ-COM-RIP, respectively. These RIPs exhibited different distribution patterns among Chinese indigenous breeds and Western commercial breeds. Individuals with the PPARα-ERV-RIP+/+ genotype (+/+ indicated homozygous with insertion) among Large White pigs had significantly higher (p PPARγ-COM-RIP−/− genotype had significantly higher (p PPARγ gene expression in the backfat of those with the PPARγ-COM-RIP−/− genotype (−/− indicated homozygous without insertion) was significantly greater (p p PPARγ, making PPARγ-COM-RIP a valuable molecular marker for assisted selection of backfat thickness in pig breeding.

Keywords

• <i>PPARγ</i> gene
• RIPs
• repressor
• molecular marker