title: Genome-wide association study for intramuscular fat deposition and composition in Nellore cattle.
abstract: BACKGROUND
  Meat from Bos taurus and Bos indicus breeds are an important source of nutrients for humans and intramuscular fat (IMF) influences its flavor, nutritional value and impacts human health. Human consumption of fat that contains high levels of monounsaturated fatty acids (MUFA) can reduce the concentration of undesirable cholesterol (LDL) in circulating blood. Different feeding practices and genetic variation within and between breeds influences the amount of IMF and fatty acid (FA) composition in meat. However, it is difficult and costly to determine fatty acid composition, which has precluded beef cattle breeding programs from selecting for a healthier fatty acid profile. In this study, we employed a high-density single nucleotide polymorphism (SNP) chip to genotype 386 Nellore steers, a Bos indicus breed and, a Bayesian approach to identify genomic regions and putative candidate genes that could be involved with deposition and composition of IMF.
  
  
  RESULTS
  Twenty-three genomic regions (1-Mb SNP windows) associated with IMF deposition and FA composition that each explain ≥1% of the genetic variance were identified on chromosomes 2, 3, 6, 7, 8, 9, 10, 11, 12, 17, 26 and 27. Many of these regions were not previously detected in other breeds. The genes present in these regions were identified and some can help explain the genetic basis of deposition and composition of fat in cattle.
  
  
  CONCLUSIONS
  The genomic regions and genes identified contribute to a better understanding of the genetic control of fatty acid deposition and can lead to DNA-based selection strategies to improve meat quality for human consumption.
authors.forename: Aline S M
authors.initials: AS
authors.lastname: Cesar
authors.forename: Luciana C A
authors.initials: LC
authors.lastname: Regitano
authors.forename: Gerson B
authors.initials: GB
authors.lastname: Mourão
authors.forename: Rymer R
authors.initials: RR
authors.lastname: Tullio
authors.forename: Dante P D
authors.initials: DP
authors.lastname: Lanna
authors.forename: Renata T
authors.initials: RT
authors.lastname: Nassu
authors.forename: Maurício A
authors.initials: MA
authors.lastname: Mudado
authors.forename: Priscila S N
authors.initials: PS
authors.lastname: Oliveira
authors.forename: Michele L
authors.initials: ML
authors.lastname: do Nascimento
authors.forename: Amália S
authors.initials: AS
authors.lastname: Chaves
authors.forename: Maurício M
authors.initials: MM
authors.lastname: Alencar
authors.forename: Tad S
authors.initials: TS
authors.lastname: Sonstegard
authors.forename: Dorian J
authors.initials: DJ
authors.lastname: Garrick
authors.forename: James M
authors.initials: JM
authors.lastname: Reecy
authors.affiliation: Department of Animal Science, University of São Paulo, Piracicaba SP 13418-900, Brazil. llcoutinho@usp.br.
authors.forename: Luiz L
authors.initials: LL
authors.lastname: Coutinho
mesh_terms: D050154:Adiposity; D000818:Animals; D001499:Bayes Theorem; D001947:Breeding; D002417:Cattle / Q000235:genetics*; D005227:Fatty Acids / Q000737:chemistry; D056726:Genetic Association Studies; D008297:Male; D008460:Meat; D018482:Muscle, Skeletal / Q000737:chemistry*; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci
chemical_list: D005227:Fatty Acids