Quantitative trait loci x maternal cytoplasmic environment interaction for development rate in Oncorhynchus myhiss

Effects of maternal cytoplasmic environment (MCE) on development rate in rainbow trout were evaluated within a quantitative trait loci (QTL) analysis framework. Previous research had identified QTL for development rate in doubled haploid (DH) progeny produced from a cross between the Oregon State University (OSU) and the Swanson (SW) River rainbow trout clonal lines. In this study, progeny for QTL mapping were produced from a cross between the OSU and Clearwater (CW) River clonal lines. Doubled haploids were produced from the OSU X CW F(1)by androgenesis rising eggs from different females (or MCEs); with androgenesis, the maternal nuclear genome was destroyed by irradiation and diploidy was restored by blocking the first embryonic cleavage by heat shock. All embryos were incubated at the same temperature and development rate quantified as time to batch. Using a linkage map constructed primarily with AFLP markers, QTL mapping was performed, including MCE covariates and QTL X NICE effects in models for testing. The major QTL for development rate in the OSU X SW cross overlaps with the major QTL found in this OSU X CW cross; effects at this locus were the same across MCEs. Both MCE and QTL X MCE effects contribute to variability in development rate, but QTL X MCE were minor and detected only at small effect QTL.