The long range goal of the research is to gain an understanding of the genetic basis of evolutionary change in salmonid fishes (trout, salmon, grayling, char, and whitefish). Dr. North will continue his study of the phenotypic effects of differences in the liver-specific expression of a phosphoglucomutase gene in rainbow trout and on the developmental genetic basis of morphological variation. Two new studies will be initiated. The objective of the first study is to test the assumption that mitochondrial DNA genotypes do not have phenotypic effects, and therefore, are selectively neutral. Demonstration that mtDNA is subject to natural selection would have important implications for the widespread use of mtDNA as a marker for studies of genetic variation and population structure. The second new study will test if previously observed effects of multiple locus heterozygosity is caused by the loci examined or by closely linked chromosomal segments. The major significance of this work is increasing our understanding of the phenotypic effects and evolutionary importance of genetic variation in the regulation and expression of genes. Furthermore, the studies with multiple locus heterozygosity will provide an important test of the significance of genetic variation in natural populations. Results will be applied to the management of trout and salmon populations, as well as to the conservation of biological diversity.
