Positional candidate cloning of a QTL in dairy cattle: identification of a missense mutation in the bovine DGAT1 gene with major effect on milk yield and composition

Genome Res. 2002 Feb;12(2):222-31. doi: 10.1101/gr.224202.


We recently mapped a quantitative trait locus (QTL) with a major effect on milk composition--particularly fat content--to the centromeric end of bovine chromosome 14. We subsequently exploited linkage disequilibrium to refine the map position of this QTL to a 3-cM chromosome interval bounded by microsatellite markers BULGE13 and BULGE09. We herein report the positional candidate cloning of this QTL, involving (1) the construction of a BAC contig spanning the corresponding marker interval, (2) the demonstration that a very strong candidate gene, acylCoA:diacylglycerol acyltransferase (DGAT1), maps to that contig, and (3) the identification of a nonconservative K232A substitution in the DGAT1 gene with a major effect on milk fat content and other milk characteristics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyltransferases / genetics*
  • Alanine
  • Alleles
  • Amino Acid Sequence / genetics
  • Amino Acid Substitution / genetics
  • Animals
  • Cattle
  • Chromosomes, Artificial, Bacterial / genetics
  • Cloning, Molecular* / methods
  • Contig Mapping / veterinary
  • Diacylglycerol O-Acyltransferase
  • Female
  • Gene Expression Regulation, Enzymologic / genetics
  • Gene Order / genetics*
  • Genetic Markers / genetics
  • Humans
  • Lactation
  • Lysine
  • Male
  • Mice
  • Milk / chemistry
  • Milk / enzymology*
  • Milk / metabolism*
  • Molecular Sequence Data
  • Mutation, Missense / genetics*
  • Quantitative Trait, Heritable*
  • Rats
  • Sequence Alignment / veterinary


  • Genetic Markers
  • Acyltransferases
  • Diacylglycerol O-Acyltransferase
  • Lysine
  • Alanine

Associated data

  • GENBANK/AY065621