Genetic mapping of the QTL affecting body weight in chickens using a F-2 family

1. To identify the quantitative trait loci (QTL) affecting growth in chicke ns, we carried out QTL analysis on chicken growth traits using a population of 227 F-2 crosses between a Satsumadori (slow-growing, light-weight Japan ese native breed used as a meat chicken) male and a White Plymouth Rock (ea rly-maturing, heavy weight broiler). 2. We chose 78 microsatellite loci from 331 publicly available on 14 linkag e groups, with respect to their utility and location. 3. Two QTLs affecting body weight at 13 and 16 weeks were mapped at 220 cM on chromosome 1 (LOD scores, 2.8 and 4.5, respectively, at 13 and 16 weeks) , and at 60 cM on chromosome 2 (LOD scores, 6.2 and 8.1, respectively, at 1 3 and 16 weeks). 4. The closest loci to the QTLs were LEI71 on chromosome 1 and LMU13 and MC W184 on chromosome 2. 5. The sites of the QTLs agreed closely with those already reported. Theref ore, it seems likely that QTLs affecting growth of chickens are located at these sites.