Plant, Animal & Microbe Genomes X Conference Plant, Animal & Microbe Genomes X ConferenceJanuary 12-16, 2002
Town & Country Convention Center
San Diego, CA
Workshop: Aquaculture
Muscle red-orange coloration due to accumulation of carotenoid pigments is a generalized characteristic in salmonid fishes, and it is also an important economic trait. There are evidences that salmon muscle coloration is a complex trait, and that individual differences of coloration are attributable to additive genetic differences among individuals. In coho salmon cultivated in Chile (IFOP-Coyhaique Hatchery) the heritability of visual and instrumental coloration variables fluctuates between 0.20 (red component, color space L*a*b*) and 0.26 (1-8 scale, Roche Colour Card). Although these heritability values may allow response to selection, muscle coloration in salmon cannot be deduced from its external morphology. This has prevented that this trait could be accessible to the traditional selection methods. Due to the significant economic value of muscle coloration, we initiated a search of molecular markers associated to genetic determinant of pigmentation of potential use to assist salmon breeding programs. The identification of RAPD polymorphisms associated to coloration has been carried out in 933 fishes from genealogized population, using the selective genotyping approach. Our approach has been to use the breeding value for each coloration variable to select the fish used to build the DNA pools from a restricted maximum likelihood algorithm (DFREML) using a mixed model. From 350 primer tested, two RAPD polymorphisms have been identified associated to coloration (UBC-206 and UBC249 primers). Both RAPD fragments have been cloned and sequenced to derive SCAR markers. We discuss the approach used in the search of markers associated to complex trait in fish outbreed populations. Supported by FONDECYT, Grant 2000-058.