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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 8/30/2007 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: We have initiated development of genetically defined yellow perch (Perca flavescens) broodstocks. For this, sixteen wild perch populations throughout the U.S. were sampled and analyzed using published (Leclerc et al. Molecular Ecology 2000, 9: 993-1011) and newly developed microsatellite loci. Genetic analysis shows two population clusters, one containing East Coast populations (North Carolina, and Maryland) and one from the Midwest (Wisconsin, North Dakota, and Lake Michigan). The average expected heterozygosity was similar for both clusters and ranged from 0.62-0.77 (mean=0.66) for Midwest samples and 0.65-0.78 (mean=0.72) for East Coast samples. The average number of alleles per locus ranged from 9.4 (Devils Lake, North Dakota) to 12.8 (Lac Du Flambeau, Wisconsin) (mean=11.3) in the Midwest Samples, and 10.5 (Choptank River, Maryland) to 12.9 (Perquimans River, North Carolina) (mean=11.7) for the East Coast samples. Based on this genetic analysis, 3 distinct populations (Perquimans River, North Carolina; Choptank River, Maryland; and Lake Winnebago, Wisconsin) were selected for generating F1 broodstock strains. Pre-spawn adults were collected from the wild and spawned by hand. Single pairwise crosses were made and fin clips were collected from each adult. Fertilized eggs were incubated with one family per aquarium at the Great Lakes WATER Institute (Milwaukee, WI). Upon hatching, equal numbers of progeny from 14 (Perquimans River) - 32 (Lake Winnebago) unique parental crosses were counted by hand into strain specific tanks. When fingerlings reached 1.5-2 g, 650 individuals were then randomly stocked into 6ft circular flow through tanks, with four replicates per strain (12 tanks total) for performance trials. To monitor growth, representative numbers of fish from each tank are sampled for length and weight every 15 days. After this initial performance trial, the top performers/strain will be crossed to produce an F2 generation that should exhibit enhanced growth. In addition to selecting for desired traits, maintaining genetic diversity and avoiding inbreeding are priorities. To address this, a subset of individuals within each strain was analyzed. At three months post hatch, fin clips were obtained from equal numbers of individuals representing four different size classes. Size classes were based on data collected while monitoring growth. Microsatellites used for the initial population genetics were amplified for each individual and analyzed. Parentage analysis was completed using PROBMAX to determine the parental contribution to different size classes. Arlequin was used to compare the genetic diversity between individuals in different size classes and their parents. Data on parentage analysis and genetic diversity will be presented. |
