A chromosome-wide QTL mapping on chromosome 2 to identify loci affecting live weight and carcass traits in F2 population of Japanese quail

The Japanese quail (Coturnix japonica) is a considerable species which is often used for animal modelling in breeding researches. This study aims to detect quantitative trait loci (QTL) underlying growth and carcass traits in Japanese quail. A three-generation resource population was developed using wild and white Japanese quail strains. The total mapping population consisted of 472 birds. Eight pairs of white and wild birds were mated reciprocally and 34 F1 birds were generated. The F1 birds were intercrossed to produce F2 offspring (422 birds). All of the animals from three generations were genotyped for four microsatellite markers on chromosome 2 in quail. QTL analysis was performed with the Least Squares interval mapping method. The results indicated significant QTL for breast weight, carcass weight, pre-stomach weight, pancreas percentage, head weight, intestine weight, spleen weight, and heart weight. There was also evidence for dominance QTL affecting pre-stomach weight, percentage of pre-stomach weight, and percentage of breast on chromosome 2. The proportion of F2 phenotypic variation explained by significant additive and dominance QTL effects ranged from 1.06 to 3.33% and 0.71 to 4.36%, respectively. There was no evidence for imprinting effect on the studied traits.