Expression and Genetic Effects of GLI Pathogenesis-Related 1 Gene on Backfat Thickness in Pigs

Backfat thickness (BFT) is an important carcass composition trait and regarded as a breeding focus. Our initial transcriptome analysis of pig BFT identified GLI pathogenesis-related 1 (GLIPR1) as one of the promising candidate genes. This study was conducted to identify the expression profiles, polymorphisms, and genetic effects of the GLIPR1 gene on BFT in pigs. The expression of the GLIPR1 gene existed in every detected tissue, and there was a significantly higher expression in spleen and adipose tissue than others (p < 0.05). At the different ages of pig, the expression of the GLIPR1 gene was low at an early age, increased with growth, and reached the highest level at 180 days. Genetic polymorphism analysis was detected in 553 individuals of the Large White × Minzhu F2 population. Four SNPs in the promoter significantly associated with 6−7 rib BFT (p < 0.05) were predicted to alter the transcription factor binding sites (TFBS), and the mutations of g.38758089 T>G and g.38758114 G>C were predicted to change the TFs associated with the regulation of adipogenesis. Haplotypes were formed by the detected SNPs, and one block showed a strong association with BFT (p < 0.05). In summary, our results indicate that the expression profiles and genetic variants of GLIPR1 affected the BFT of pigs. To our knowledge, this study is the first to demonstrate the biological function and genetic effects of the GLIPR1 gene on the BFT of pig and provide genetic markers to optimize breeding for BFT in pigs.