QTL Mapping of Body Weight Traits on the Chromosome 1 in Japanese Quail

The aim of this study was to qtl mapping of body weight traits from hatch to 45 days on chromosome one in Japanese quail. For this purpose, a crossbred population from a four-generation crossbreeding pattern was used. The four strains A and M Texas, Wild, Italian Speckled and Tuxedo Japanese quail were crossed in diallel-cross, creating the first generation. Then, from the crossbreed of first generation, a mapping population including second, third and fourth generations was created. Blood samples were collected for DNA extraction and amplification of microsatellite markers on the chromosome 1 of the subcutaneous veins in tubes containing 0.5% EDTA. Observations included body weight traits from birth to 45 days with an interval of 5 days. The effects of markers and components of variance were performed with three models of additive, dominance and additive-dominance with AI-REML procedure of GVCBLUP software. Based on the estimated effects of markers, the point with the highest value of F statistic was reported as the QTL location. The results of QTL analysis in the additive model for hatch weight traits, 5 and 30 days indicate the presence of QTLs affecting body weight traits at the end, QTLs of 10, 15, 20, 25, 40 and 45 day body weight traits in the middle and for body weight trait 35 days, they were at the beginning of chromosome one. In the dominance model, QTLs affecting body weight traits including hatch, 5, 10, 15, 35, 40 and 45 in the middle and for body weight traits 20, 25 and 30 at the end of chromosome one were identified. The percentage of additive and dominance genetic variance due to markers in different models ranged from 0.17 to 9.4% and 3.3 to 23.3% of the total phenotypic variance, respectively. Therefore, the results of this study confirm the existence of at least two distinct gene loci with additive effects and dominance affecting body weight traits on chromosome one in Japanese quail.