Genetic epistasis analysis of 10 peroxisome proliferator-activated receptor γ-correlated genes in broiler lines divergently selected for abdominal fat content.
Chicken peroxisome proliferator-activated receptor γ (PPARγ), which is highly expressed in adipose tissues, is a key factor in fat accumulation in the abdominal fat pad. In this study, association and pairwise epistasis analyses were performed for all the polymorphisms detected in PPARγ and for 9 genes from PPARγ-correlated lipid metabolic pathways for abdominal fat weight (AFW) in 10th-generation populations of Northeast Agricultural University broiler lines divergently selected for abdominal fat content. Epistatic networks were then reconstructed with the identified epistatic effects. Single-marker association analyses showed that 5 of the 20 screened polymorphisms were significantly associated with AFW (P < 0.05), and CCAAT/enhancer-binding protein α (C/EBPα) c.552G>A was 1 of the 5 significant loci. Pairwise interaction analyses showed that 15 pairs of polymorphisms reached a significance level of P < 2.64 × 10(-4) (adjusted by Bonferroni correction) in the lean line, 41 pairs reached significance in the fat line, and 7 pairs reached significance in both lines. Interestingly, many other loci interacted with C/EBPα c.552G>A in both lines. In epistatic network analyses, C/EBPα c.552G>A seemed to behave as a hub for the epistatic network in both lines. All these results revealed that the genetic architecture of C/EBPα c.552G>A for AFW seemed to be an apparent individual main-effect QTL but that it could be dissected into a genetic epistatic network. Our results suggest that C/EBPα c.552G>A might be the most important locus contributing to phenotypic variation in AFW among all the polymorphisms detected in this study.
College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, P. R. China.
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D020121:5' Untranslated Regions / Q000235:genetics; D000005:Abdomen / Q000033:anatomy & histology; D000273:Adipose Tissue / Q000033:anatomy & histology*; D000818:Animals; D002645:Chickens / Q000033:anatomy & histology / Q000235:genetics*; D017931:DNA Primers; D004843:Epistasis, Genetic / Q000235:genetics*; D050556:Fatty Acid-Binding Proteins / Q000235:genetics; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D007438:Introns / Q000235:genetics; D009154:Mutation; D047495:PPAR gamma / Q000235:genetics*; D011110:Polymorphism, Genetic
D020121:5' Untranslated Regions; D017931:DNA Primers; D050556:Fatty Acid-Binding Proteins; D047495:PPAR gamma