Preservation of genetic variation within aquaculture stocks of white sturgeon (Acipenser transmontanus)

Nine tetramer [GATA]_n microsatellite loci were developed for use in the white sturgeon, Acipenser transmontanus. We report inheritance patterns for these nine loci to range from disomy to tetrasomy and octosomy. Due to the complex modes of inheritance of these loci, we propose each allele be scored as its own dominant marker, similar to AFLPs or RAPDs. This method is validated by the observation that individual alleles within a microsatellite locus generally fit the expectation for independent transmission and fit the expected transmission frequency for single copy nuclear markers.; We tested the utility of these loci to estimating parentage and relatedness using algorithms developed for dominant markers. Microsatellite alleles were scored as independent dominant markers and likelihood ratio statistics were used to estimate parentage. We tested three parentage scenarios: assignment to parent pairs, assignment to sires and dams independently, and assignment to sires and dams when the true sires and dams were combined with 157 other fish. Assignment accuracy to parent pairs exceeded 99%. Assignment accuracy to sires and dams independently was lower but we present methods to improve this accuracy. Pairwise relatedness estimates were made for fish from known sib groups, and the use of the UPGMA clustering algorithm to identify sib groups from a matrix of relatedness values successfully identified full sib groups.; Heritabilities and genetic correlations were estimated for body conformation and caviar production traits. Traits and estimated heritabilities were six month body length (h2 = 0.17) and weight (0.14), body weight of females at harvest (0.42), caviar weight (0.05) and caviar yield (0.08). The low heritabilities of caviar weight and yield suggest there are large environmental influences on these traits. Caviar class was affected by spawn cycle, and caviar grade was affected by rearing location. A breeding plan for improving adult body weight should produce a genetic gain in adult body weight and positively correlated caviar weight. We recommend grading fish at six months post-hatch and an individual based selection program for caviar females using breeding values for adult body weight.