ARS | Publication request: SCREENING FOR HIGHLY HETEROZYGOUS CHICKENS IN OUTBRED COMMERCIAL BROILER LINES TO INCREASE DETECTION POWER FOR MAPPING QUANTITATIVE TRAIT LOCI

Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: December 1, 1999
Publication Date: N/A

Technical Abstract: Two commercial broiler lines were used in an experiment to map quantitative trait loci (QTL) affecting disease resistance, growth, and reproduction traits. Chickens from these lines were genotyped with 27 microsatellite markers to estimate heterozygosity and polymorphism information contest (PIC). Heterozygosity estimated from allelic frequencies was 0.53 and 0.51 1for the two lines; however, heterozygosity calculated from actual counts o heterozygous loci (0.37 and 0.35, respectively) were much lower than the estimated heterozygosity. The PIC was less than 0.5 in both lines, and average allele number per marker locus was about 3.5. Twenty-five males produced from a cross between these two lines were screened with the DNA marker to select birds with high heterozygosity at marker loci. Mating simulation showed that non-informative matings can be reduced by about 5% if 12 pairs of the males and females with the highest heterozygosity at marker loci were selected. However, the percentage of non-informative matings was not reduced further if eight pairs were selected. This experiment demonstrated that the heterozygosity and PIC in commercial broiler lines were low and selection on the birds with high heterozygosity at marker loci can increase informative content in QTL mapping, thus increasing detection power.