UTILIZATION OF GENOMICS FOR IMPROVING PRODUCTION TRAITS IN COOL AND COLD WATER AQUACULTURE
Location: Cool and Cold Water Aquaculture Research
Title: A microsatellite linkage map of striped bass (Morone saxatilis) reveals conserved synteny with the hree-spined stickleback (Gasterosteus aculeatus)
Submitted to: Marine Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 2, 2011
Publication Date: October 4, 2011
Citation: Liu, S., Rexroad III, C.E., Couch, C.R., Cordes, J.R., Reece, K.S., Sullivan, C.V. 2011. A microsatellite linkage map of striped bass (Morone saxatilis) reveals conserved synteny with the hree-spined stickleback (Gasterosteus aculeatus). Marine Biotechnology. 14(2):237-244.
Interpretive Summary: Striped bass is of great importance to fisheries and aquaculture in the United States. Genetic improvement of this species through selective breeding will facilitate progress towards production efficiency. Genetic maps which reveal the relationships of markers and traits as they are inherited throughout generations are useful to develop modern approaches to improve the efficiency of animal breeding. To this end we constructed the first genetic map of the striped bass genome. This map can be used to identify regions associated with traits affecting striped bass production. A significant amount of similarity was identified by comparing the striped bass genetic map with the genome sequence of a model fish, the three-spined stickleback. Thus, the knowledge and information developed in this model fish can be used to speed up discovery and characterization of genes affecting striped bass production.
Background: The striped bass (Morone saxatilis) and its relatives (genus Morone) are of great importance to fisheries and aquaculture in North America. As part of a collaborative effort to employ molecular genetic technologies in striped bass breeding programs, nearly 500 microsatellite markers were previously developed from repeat-enriched libraries. We report on the utilization of these and other markers to construct a microsatellite linkage map of striped bass and to discover chromosome regions of conserved synteny between this species and a model teleost having a sequenced genome, the three-spined stickleback (Gasterosteus aculeatus).
Results: Of 480 microsatellite markers that were screened for polymorphism, 289 informative markers were identified and used to genotype two half-sib mapping families. Twenty-six linkage groups were assembled, and only two markers remain unlinked. The sex-averaged map spans 1696.7 cM with an average marker density of 5.97 cM per marker. The male genetic map length is 1960.6 cM, and the female genetic map length is 1609.8 cM; therefore, the overall female:male recombination ratio is 0.82:1. Among 285 striped bass microsatellite markers, 167 (58.6%) showed homology to sequences on stickleback chromosomes or scaffolds. Comparison between the stickleback genome and the striped bass linkage map revealed conserved synteny between these two species.
Conclusion: This is the first linkage map for any of the Morone species. This map will promote discovery and mapping of genes affecting biochemical processes underlying important phenotypic traits, and will facilitate utilization of marker-assisted selection in selective breeding programs. The conserved synteny between striped bass and stickleback will facilitate fine mapping of genome regions of interest and will provide a new resource for comparative mapping with other Perciformes fishes such as European sea bass (Dicentrarchus labrax), gilthead sea bream (Sparus aurata), and tilapia (Oreochromis ssp.).