Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 14, 1997
Publication Date: N/A
Technical Abstract: Commercial production of channel catfish, Ictalurus punctatus, is the largest aquaculture enterprise in the United States, with 445 million pounds of fish processed annually. Domestic channel catfish exhibit significant phenotypic variation and positive response to selection for economic traits, providing potential for improved performance with selective breeding. Therefore, development and commercial use of improved germplasm should increase production efficiency in channel catfish as it has in many livestock species. To date, we have characterized 22 tri- and tetranucleotide loci in populations of wild and domesticated fish. The loci contain from 3 to 17 alleles each in the wild population, and average heterozygosity in the population was >0.7 for 14 of the loci and >0.6 for 20 of the loci. Populations of domestic, farm-raised catfish and a research strain displayed levels of heterozygosity similar to the wild population. We wish to develop a linkage map of the channel catfish genome, based on polymorphic microsatellites, to provide ordered loci useful for marker assisted selection of genetically superior broodstock. A large effective population size of random mating broodstock and lack of sustained selective breeding have allowed channel catfish strains to maintain high levels of allelic heterozygosity, so several resource families currently within our selective breeding program may be useful as reference families for construction of the linkage map. Progress toward a physical map is hindered by difficulties in catfish chromosome karyotyping. Marker assisted selection of genetically superior broodstock will lead to improved performance of farm-raised channel catfish populations.