Identification of quantitative trait loci associated with weight and percentage of internal organs on chromosome 1 in Japanese quail

The purpose of this study was to identify genomic regions affecting weight and percentage of internal organs on chromosome 1 in an F2 population of Japanese quail. A three-generation resource population was developed by using two distinct Japanese quail strains, wild (meat type) and white (layer type). Eight pairs of white and wild birds were crossed reciprocally and 34 F1 birds were produced. The F1 birds were intercrossed to generate 422 F2 offspring. Phenotypic data including weight of organs were collected on F2 birds. All of the animals from three generations (472 birds) were genotyped for eight microsatellite markers on chromosome 1. QTL analysis was performed with least square regression interval mapping method fitting three various statistical models. Significant QTL were identified for pre-stomach weight, uropygial gland weight, bursa of fabricius weight, gizzard weight, percentage of pre-stomach, percentage of intestine, percentage of uropygial gland and percentage of bursa of fabricius. The proportion of the F2 phenotypic variation explained by the significant additive, dominance and imprinted QTL effects ranged from 4.06 to 7.29%, 1.96 to 4.65% and 2.7 to 6.25%, respectively. The results of this study show that there are quantitative trait loci associated with weight and percentage of internal organs on chromosome 1 in Japanese quail, but more studies are needed to better understand genetic structure of these traits.