Location: Warmwater Aquaculture Research UnitTitle: A standardized microsatellite marker panel for parentage and kinship analyses in channel catfish, Ictalurus punctatus Author
Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/29/2012
Publication Date: 8/1/2013
Citation: Waldbieser, G.C., Bosworth, B.G. 2013. A standardized microsatellite marker panel for parentage and kinship analyses in channel catfish, Ictalurus punctatus. Animal Genetics. 44:476-479. Interpretive Summary: The development of pedigreed catfish populations for genetic selection and the analysis of individual and family differences in performance is hindered by the similar physical characteristics of all catfish. Therefore methods are needed to efficiently identify catfish. We produced a standardized set of molecular markers for DNA fingerprinting and tested them on outbred and closely-bred populations. The markers allowed us to identify the parents for 694 of 697 spawns collected from earthen ponds over three years. The markers also allowed us to classify all but one of 374 individuals from ten families that had been co-cultured in a pond for one year. The standardized markers enable the development of pedigreed catfish populations and large scale performance evaluations in common environments to support the genetic improvement of cultured catfish through selective breeding.
Technical Abstract: This research was designed to produce a standardized set of microsatellite loci for parentage and kinship analyses in channel catfish, the leading species in U.S. aquaculture. Three panels of 5 to 6 markers each were developed that contained a total of 2 dinucleotide, 8 trinucleotide, and 7 tetranucleotide microsatellite loci. The loci contained a range of 9 to 31 alleles per locus in an outbred population. Based on allele frequencies measured in commercial randomly-bred broodstock, the combined probability of non-exclusion of an unrelated candidate parent pair was 5.36e-18. The combined probability of non-exclusion of unrelated identical genotypes was 2.58e-08. The microsatellite panels were validated by parentage and kinship evaluation in three populations. A total of 697 spawns were collected from matings of outbred broodstock over three spawning seasons and parents were determined unambiguously for all but three spawns. Genotype analysis also enabled the identification of half-sibling and full-sibling families produced by pond spawning. In a second experiment, parentage was unambiguously determined in nine spawns from a population consisting of broodstock derived from only four families. A third experiment demonstrated that all but 1 of 374 individuals from ten full-sibling families could be assigned to a family after co-culture in an earthen pond for one year. The standardized microsatellite panels enable the development of pedigreed catfish populations and large scale performance evaluations in common environments to support the genetic improvement of cultured catfish through selective breeding.