Plant & Animal Genome VII Conference

W8

FINDING THE GENES THAT COUNT: THE SEARCH FOR QTL REGIONS IN RAINBOW TROUT

Department of Zoology, University of Guelph, Guelph, ON Canada N1G 2W1

We are integrating molecular genetic technologies into salmonid aquaculture to help solve some of the major genetic problems that hinder the development of the trout-farming industry. Our long term goal is to use genetic markers to increase the efficiency of artificial selection in rainbow trout stock development and improvement. To do this, we are constructing a linkage map of over 300 loci that is being used to locate quantitative trait loci (QTL) for upper temperature tolerance, spawning date, growth, and age of maturation in reference families produced by crossing strains that differ for these economically important traits. We focus on microsatellite loci because their high variability and codominant expression allow increased precision in tracking specific alleles and their association with QTL in different progeny groups. In addition, we are determining whether the QTL identified in the reference families are showing detectable effects in trout at commercial breeding facilities. Subsequently, fish with a particular marker genotype that is associated with a desirable phenotype due to linkage with a QTL will be used for breeding (marker assisted selection, MAS). Knowledge of family structure is expected to lead to higher rates of genetic improvement while minimizing inbreeding.