Submitted to: Proceedings New Zealand Society of Animal Production
Publication Type: Proceedings
Publication Acceptance Date: February 1, 1997
Publication Date: N/A
Technical Abstract: Genetic linkage maps have been developed to identify the regions of the genome (loci) that are responsible for the genetic variation associated with a trait. Identification of trait loci allows selection of animals containing the more desirable alleles, with DNA markers (Marker Assisted Selection). Alternatively, the locus can be mapped to a very specific DNA sequence and diagnostic tests can be developed to determine which alleles are present in each animal. Mapping quantitative trait loci (QTL) is accomplished most efficiently in populations designed to accentuate the genetic variation associated with the trait of interest. A QTL study designed to map meat tenderness loci has been initiated with a F1 Brahman/Hereford and a Brahman/Angus sire because of the large breed substitution effect for tenderness between Brahman and Hereford or Angus. A second QTL study designed to map percent retail product loci utilized two paternal half-sib families from a F1 Belgium Blue/MARCIII (¬ Hereford, Angus, Pinzgaurer and Red Poll) and a F1 Piedmontese/Angus sire. The current USDA bovine linkage map contains 1,251 markers in 30 linkage groups representing the 29 autosomal chromosomes and the X chromosome. The resolution of this is map is sufficient to identify loci influencing traits of interest and map them to <3 cM region (<3 million bases).