Date of Graduation
Davis College of Agriculture, Natural Resources and Design
Animal and Nutritional Sciences
Robert A Dailey
Implementation of modern fishing techniques and hatchery technologies necessitates use of genetics in management of fishery stocks. Genetic analysis of rainbow trout, Oncorhynchus mykiss, will assist development of superior strains of a valuable aquacultured species. This study was to (1) develop polymorphic microsatellite markers to examine for variation among rainbow trout strains and develop an identification panel of microsatellites to distinguish individual strains, and (2) to identify novel genes and estimate relative gene expression profiles (expressed sequence tags from rainbow trout liver, intestine, kidney, and ovary non-normalized libraries). Thirty-seven microsatellites were identified by screening 576 clones from TAGA and ATG-repeat enriched libraries. Allele frequencies were used to determine number of alleles per locus, percentage of variable loci, and mean heterozygosity, and calculation of F-statistics using GenePop and Bisosys software. Further analysis of ten individuals of ten strains with 13 markers was produced unique genotypes. Observed heterozygosity over all loci was less than the expected Hardy-Weinberg values. Mean FIS values were high in Wytheville and Ennis strains, suggestive of inbreeding. Between-strain heterogeneity tests were significant (p<0.001) for all pair-wise comparisons of strains, thus each strain is considered unique. Allele frequencies allowed correct assignment of 92% of individuals to strain of origin. Analysis of expressed sequence tags identified 90, 8, 19, 47 previously unknown genes in intestine, liver, kidney, and ovary, respectively. Overall, Wytheville trout appear to be least diverse. Many genes were in more than one tissue, suggesting potential use as positive-controls in PCR-based studies in these tissues.
Stewart, Amanda B., "Genetic analysis of rainbow trout (Oncorhynchus mykiss): Strain identification via microsatellites and analysis of expressed sequence tags in intestine, liver, kidney, and ovary" (2006). Graduate Theses, Dissertations, and Problem Reports. 4272.