Association of a lysine-232/alanine polymorphism in a bovine gene encoding acyl-CoA:diacylglycerol acyltransferase ( DGAT1 ) with variation at a quantitative trait locus for milk fat content

• DOI: 10.1073/pnas.142293799
• Publication Date: 2002-07-28T22:26:28Z
• Authors: Andreas Winter; Wolfgang Krämer; Fabian A. O. Werner; Sonja Kollers; Srinivas Kata; Gregor Durstewitz; Johannes Buitkamp; James E. Womack; Georg Thaller; Ruedi Fries
• Keywords: 0301 basic medicine; 2. Zero hunger; Polymorphism, Genetic; Base Sequence; Sequence Homology, Amino Acid; Molecular Sequence Data; Chromosome Mapping; Genetic Variation; DNA; Dietary Fats; 03 medical and health sciences; Milk; Quantitative Trait, Heritable; Haplotypes; Animals; Cattle; Female; Amino Acid Sequence; Diacylglycerol O-Acyltransferase; Acyltransferases; Alleles

DGAT1 encodes diacylglycerol O -acyltransferase (EC 2.3.1.20 ), a microsomal enzyme that catalyzes the final step of triglyceride synthesis. It became functional candidate gene for lactation traits after studies indicated mice lacking both copies are completely devoid milk secretion, most likely because deficient synthesis in mammary gland. Our mapping placed close to region quantitative trait locus (QTL) on bovine chromosome 14 variation fat content milk. Sequencing from pooled DNA revealed significant frequency shifts at several variable positions between groups animals with high and low breeding values different breeds (Holstein–Friesian, Fleckvieh, Braunvieh). Among variants was nonconservative substitution lysine by alanine (K232A), lysine-encoding allele being associated higher content. Haplotype analysis variant be ancestral. Two were typed heterozygous ( Qq ) QTL based marker-assisted QTL-genotyping K232A substitution, whereas qq homozygous alanine-encoding allele. An independent association study Fleckvieh confirmed positive effect We consider directly responsible variation, although our genetic cannot provide formal proof.