Integration of association and computational methods reveals functional variants of LEPR gene for abdominal fat content in chickens

Leptin receptor(LEPR)plays a vital role in obesity in humans and animals.The objective of this study is to assess LEPR functional variants for chicken adipose deposition by integration of association and in-silico analysis using a unique chicken population,the Northeast Agricultural University broiler lines divergently selected for abdominal fat content(NEAUHLF).Five online bioinformatics tools were used to predict the functionality of the single nucleotide polymorphisms(SNPs)in coding region.Further,the possible structure–function relationship of high confidence SNPs was determined by bioinformatics analyses,including the conservation and stability analysis based on amino acid residues,prediction of protein ligand-binding sites,and the superposition of protein tertiary structure.Meanwhile,we analyzed the association between abdominal fat traits and 20 polymorphisms of chicken LEPR gene.The integrated results showed that rs731962924(N867I)and rs13684622(C1002R)could lead to striking changes in the structure and function of proteins,of which rs13684622(C1002R)was significantly associated with abdominal fat weight(AFW,P=0.0413)and abdominal fat percentage(AFP,P=0.0260)in chickens.Therefore,we are of the opinion that rs13684622(C1002R)may be an essential functional SNP affecting chicken abdominal fat deposition,and potentially applied to improvement of broiler abdominal fat in molecular marker-assisted selection(MAS)program.Additionally,the coupling of association with computer electronic predictive analysis provides a new avenue to identify important molecular markers for breeders.

Integration of genome-wide association study and selection signatures reveals genetic determinants for skeletal muscle production traits in an F2 chicken population

Improving the production of broiler chicken meat has been a goal of broiler breeding programs worldwide for many years. However, the genetic architectures of skeletal muscle production traits in chickens have not yet been fully elucidated. In the present study, a total of 519 F_(2) birds, derived from a cross of Arbor Acres broiler and Baier layer, were re-sequenced(26 F_(0) individuals were re-sequenced at a 10-fold depth;519 F_(2) individuals were re-sequenced at a 3-fold depth) and the coupling of genome-wide association study(GWAS) and selection signatures(FST(fixation index) and θπ(nucleotide diversity)) was carried out to pinpoint the associated loci and genes that contribute to pectoral muscle weight(PMW) and thigh muscle weight(TMW). A total of 7 890 258 single nucleotide polymorphisms(SNPs) remained to be analyzed after quality control and imputation. The integration of GWAS and selection signature analyses revealed that genetic determinants responsible for skeletal muscle production traits were mainly localized on chromosomes 1(168.95–172.43 Mb) and 4(74.37–75.23 Mb). A total of 17 positional candidate genes(PCGs)(LRCH1, CDADC1, CAB39 L, LOC112531568, LOC112531569, FAM124 A, FOXO1, NBEA, GPALPP1, RUBCNL, ARL11, KPNA3, LHFP, GBA3, LOC112532426, KCNIP4, and SLIT2) were identified in these regions. In particular, KPNA3 and FOXO1 were the most promising candidates for meat production in chickens. These findings will help enhance our understanding of the genetic architecture of chicken muscle production traits, and the significant SNPs identified could be promising candidates for integration into practical breeding programs such as genome-wide selection(GS) to improve the meat yield of chickens.