Bayesian Analysis for Genetic Architectures of Body Weights and Morphological Traits Using Distorted Markers in Japanese Flounder Paralichthys olivaceus

A doubled haploids (DH) population of 160 individuals is constructed by using mitotic gynogenetics for the study of genetic architectures of the body weight and morphological traits in Japanese flounder. Each DH individual is genotyped for 458 SSR markers, 222 of which segregate distortionally. By modifying conditional probabilities of quantitative trait locus (QTL) genotypes on the distorted flanking markers, Bayesian model selection is used to dissect genetic architectures for the traits. As a result, we identify 42 main-effect QTLs on chromosomes 5, 6, 7, 8, 9, 10, 15, 20, 21, 22, and 59 pairs of interacting QTLs. Among these detected QTLs, the largest interacting QTL is between chromosome 6 and chromosome 9 and accounts for 25.196 % of phenotypic variance for body weights and in a similar trend. Also, many QTLs show pleiotropic effects. The QTL on chromosome 9 simultaneously governs seven traits, BL, BH, FL, HL, PFL, HW, and CW. As compared to method using the uncorrected conditional probabilities of QTL genotypes, our method using corrected conditional probabilities can detect more interacting QTLs for the traits.