Effect of SNPs in the Promoter Region on the Expression of Cytochrome P450 2E1 (CYP2E1) in Pig Liver

Holly Archer; Riani A N Soares; Mohsen Jafarikia; Brandon N Lillie; Flavio Schenkel; E James Squires

doi:10.3390/ani14081163

Effect of SNPs in the Promoter Region on the Expression of Cytochrome P450 2E1 (CYP2E1) in Pig Liver

Animals (Basel). 2024 Apr 12;14(8):1163. doi: 10.3390/ani14081163.

Authors

Holly Archer¹, Riani A N Soares¹, Mohsen Jafarikia^{1

2}, Brandon N Lillie³, Flavio Schenkel¹, E James Squires¹

Affiliations

¹ Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
² Canadian Centre for Swine Improvement Inc., Ottawa, ON K1A 0C6, Canada.
³ Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada.

Abstract

Boar taint, an unfavorable odor in the meat of intact male pigs, is caused primarily by the accumulation of two compounds: androstenone and skatole. This multifactorial trait is regulated by numerous dietary, management and genetic factors. At the mechanistic level, there are many genes known to be involved in boar taint metabolism. Cytochrome P450 2E1 (CYP2E1) impacts boar taint through the phase I metabolism of skatole. The aim of this study was to identify single-nucleotide polymorphisms (SNPs) within the CYP2E1 gene promoter and explore their relationship with the expression of CYP2E1 mRNA and protein. Sequencing of the promoter region using pools of genomic DNA identified seven promoter region SNPs at -159, -586, -1693, -1806, -2322, -2369 and -2514 bp upstream of the ATG start site. Genomic DNA was obtained from 65 boars from the three major swine breeds: Duroc, Landrace and Yorkshire, and individual animals were genotyped for the identified SNPs. RNA was isolated from liver tissue and quantitative PCR was performed to measure CYP2E1 gene expression, while levels of CYP2E1 protein in liver were measured by Western blotting. Significant within-breed variation in CYP2E1 protein and mRNA expression was observed, indicating significant differences in gene expression among individuals. However, levels of CYP2E1 mRNA and protein were not significantly correlated. Two SNPs within the promoter were significantly associated with CYP2E1 mRNA expression, but not with protein expression. This study provides evidence of additional mutations affecting the gene expression of CYP2E1 and suggests that factors that affect the differences in translation of CYP2E1 mRNA may also be important in affecting skatole metabolism.

Keywords: gene expression; promoter region; single-nucleotide polymorphism.

Grants and funding

Funding was provided by the Agricultural Adaptation Council in Ontario which manages the Canadian Agricultural Adaptation Program (CAAP) on behalf of Agriculture and Agri-Food Canada. Support was also provided by Swine Innovation Porc and the regional swine improvement centers across Canada, the Canadian Center for Swine Improvement, and participating Canadian breeders. Special thanks to the Ontario Swine Improvement for their financial contribution and the dedication of their staff time to sample fat tissues.