Inheritance of resistance to Ceratomyxa shasta in progeny from crosses between high- and low-susceptibility strains of rainbow trout (Oncorhynchus mykiss)

摘要

Susceptibility to Ceratomyxa shasta among a susceptible and resistant strain of rainbow trout (Oncorhynchus mykiss) and their reciprocal Fl progeny was measured as mortality following natural exposure to the parasite. Mortality from C. shasta among progeny of the susceptible parental line was 75 percent following a 3-d exposure, and reached 98 percent after a 5-d exposure. Mortality from C. shasta in all genetic groups with at least one parent of the resistant strain remained below 5 percent regardless of exposure duration. These data indicate that resistance is a dominant trait for the crosses tested. The identification of a rainbow trout model in which resistance to a pathogen is passed as a dominant trait will be valuable for studies mapping genes for disease resistance and in the identification of the physiological response that dictates the trait.