Genome Scan for Selection in Structured Layer Chicken Populations Exploiting Linkage Disequilibrium Information

Area of Science:

• Population Genetics
• Genomics
• Animal Breeding

Background:

• Understanding genotype-phenotype relationships is crucial for animal breeding.
• Detecting signatures of selection in genomic regions aids in identifying genes targeted by artificial selection.
• Layer chicken breeds exhibit distinct genetic profiles due to selective breeding for production traits.

Purpose of the Study:

• To detect selective signatures in commercial layer chicken populations.
• To evaluate the efficacy of the hapFLK method in identifying selection signatures.
• To identify genes and quantitative trait loci (QTL) associated with production traits in layer chickens.

Main Methods:

• Analysis of 70 individuals from three commercial layer breeds (White Leghorn, White Rock, Rhode Island Red).
• Genotyping using approximately 1 million single nucleotide polymorphisms (SNPs).
• Application of the hapFLK method, which utilizes linkage disequilibrium and accounts for population structure, alongside its single SNP counterpart, FLK.

Main Results:

• Identified 41 regions with outstanding differentiation and 107 regions with similarity using hapFLK.
• Detected genes associated with growth, carcass traits (e.g., IGF-1R, AGRP, STAT5B), and feather color (SOX10).
• Demonstrated that hapFLK, by exploiting linkage disequilibrium and population structure, reduced the false detection rate compared to FST and FLK.

Conclusions:

• The hapFLK method is effective for detecting selection signatures in layer chickens.
• Identified genomic regions and genes provide insights into the genetic basis of production and phenotypic traits in layer breeds.
• Accounting for linkage disequilibrium and population structure improves the accuracy of selection signature detection.