Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 15, 2005
Publication Date: January 15, 2005
Citation: Zhou, H., Deeb, N., Evock-Clover, C., Ashwell, C.M., Lamont, S.J. Genome-wide linkage and QTL mapping of phenotypic traits in the chicken. Poultry Science. 2004. Abstract p. 209.
A genome scan was used to identify chromosomal regions and eventually quantitative trait loci (QTL) that affect quantitative traits of economic importance. Two informative chicken F2 populations generated from broiler, Leghorn, and Fayoumi lines have been used for genome-wide linkage and QTL analysis. A total of 417 and 325 F2 progeny were used for genome scans from broiler x Leghorn crosses and broiler X Fayoumi crosses, respectively. All F2 birds were phenotyped for a total of 42 traits in growth (8), body composition (12), skeletal integrity (12), and metabolic traits (10). Birds were genotyped for 269 microsatellite markers across 22 chromosomes and 2 linkage groups in chickens. There were 195 and 191 microsatellite markers used for linkage map and interval mapping with average spacing of markers of 21.6 and 19.8 cM in broiler x Leghorn crosses and broiler x Fayoumi crosses, respectively. The Crimap was used to compute marker linkage maps. The QTL Express was used for QTL detection. Significance thresholds were determined by permutation tests. For all four groups of traits in broiler x Leghorn crosses, 269 and 98 QTLs were significant at the 5% and 1% chromosome-wide level, respectively, while 210 and 89 QTLs were significant at the 5% and 1% chromosome-wide level in broiler x Fayoumi crosses, respectively. Closely correlated traits showed similar QTL profiles within each F2 cross. Different QTL positions and effects were observed between the two different F2 crosses. The interval mapping results in this study lay the foundation for the subsequent steps in further fine mapping and positional cloning of causative genes, and therefore is significant for animal improvement in the future.