QTL Mapping for Meat Color Traits Using the F₂ Intercross between the Oh-Shamo (Japanese Large Game) and White Leghorn Chickens

摘要

Meat color traits have economic importance and are regulated by multiple genetic loci (quantitative trait loci: QTLs), environmental factors, and their interactions. Using an F₂ intercross population between the Oh-Shamo (Japanese Large Game) and White Leghorn chickens, QTL analysis based on the Bayesian model was performed for meat color traits. A total of 280 F₂ individuals at 20 weeks of age were genotyped for 88 microsatellite markers covering 21 autosomes. As a result, nine QTLs (two on chromosome 1, two on chromosome 2, and one each on chromosomes 3, 7, 9, 17, and 24) were detected for L* (lightness), a* (redness), and b* (yellowness) values in the breast and thigh muscles. Some QTLs had a single genetic effect only on a meat color trait, however some QTLs exhibited plural genetic effects on the same and/or different traits. For example, the chromosome 3 QTL for the b* value in the raw breast muscle had main, sex-specific, and epistatic-interaction effects on the same trait, and furthermore it had an epistatic effect on a different trait (L* value in the minced thigh muscle). The chromosome 7 QTL had a sex-specific effect on the a* value in raw breast muscle and also had an epistatic effect on a different trait (b* value in the minced thigh muscle). These results clearly indicated that the genetic control of meat color is complex. In addition, this is the first report of QTL mapping focused on the epistatic interaction for meat color traits in chickens.