[Construction of genetic linkage map and QTL detection of chromosome 3 in sheep]

Based on the reference family of Sichuan liangshan semi-fine sheep, the genetic linkage map was constructed by Crimap 2.4 software, which was used to detect the QTLs for growth traits by QTLExpress with nine microsatellite markers located on chromosome 3 in sheep. The results indicated that: (1) the mean of the polymorphic information content was 0.606 (0.378-0.738), and the mean heterozygosity was 0.650 (0.404-0.766); (2) the length of the linkage map was 339.8 cM, which was longer than the length of map built by the international major drawing organization for sheep with the average distance of markers of 42.5 cM; (3) The QTLs for weaning weight, weaning daily gain, and 2.5 year weight were detected at 99 cM, 219 cM, 273 cM, respectively. The effect of QTLs on weaning daily gain trait and 2.5 year weight trait were significant, except for weaning weight trait.