title: A genome-wide association study reveals a quantitative trait locus for age at first calving in delta/notch-like EGF repeat containing on chromosome 2 in Japanese Black cattle.
abstract: Age at first calving (AFC) is an important trait for achieving earlier reproductive performance in cattle. To identify quantitative trait loci for AFC in Japanese Black cattle, we conducted a genome-wide association study using 866 animals with extreme AFC values selected from a larger group of 52, 009 animals. We identified single nucleotide polymorphisms (SNPs) on bovine chromosome 2 that were associated with AFC. These SNPs were located within 112.8-kbp intronic region of delta/notch-like EGF repeat containing (DNER) and proved to be in a state of high linkage disequilibrium. The association was replicated in an independent sample of 2963 animals. In the replicated population, the frequency of the reduced AFC allele (Q) was 0.463, and the allele accounts for 8% of the total genetic variance. The effect of allele substitution on AFC was a decrease of 11.54 days. The results suggest that the Q allele could serve as a useful marker in Japanese Black cattle to select animals with superior AFC performance.
authors.affiliation: Shirakawa Institute of Animal Genetics, Japan Livestock Technology Association, Odakura, Nishigo, Fukushima, 961-8061, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Sasaki
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ibi
authors.forename: Shogo
authors.initials: S
authors.lastname: Ikeda
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Sugimoto
mesh_terms: D000367:Age Factors; D000818:Animals; D002417:Cattle; D033481:Chromosomes, Mammalian; D056726:Genetic Association Studies; D005838:Genotype; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D011956:Receptors, Cell Surface / Q000235:genetics*; D012098:Reproduction / Q000235:genetics*
chemical_list: D011956:Receptors, Cell Surface
keywords: age at first calving (AFC); delta/notch-like EGF repeat containing (DNER); genome-wide association study (GWAS)