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.
Hu
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College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, P. R. China.
Wang
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SZ
Wang
Z P
ZP
Li
Y M
YM
Li
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H
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