51 research outputs found
Microsatellite primers for red drum (Sciaenops ocellatus)
In this note, we document polymerase-chain-reaction (PCR) primer pairs for 101 nuclear-encoded microsatellites
designed and developed from a genomic library for red drum (Sciaenops ocellatus). Details of the genomic library construction, the sequencing of positive clones, primer design, and PCR protocols may be found in Karlsson et al. (2008). The 101 microsatellites (GENBA NK Accession Numbers
EU015882-EU015982) were amplified successfully and used to genotype 24 red drum obtained from Galveston Bay, Texas (Table 1). A total of 69 of the microsatellites had an uninterrupted (perfect) dinucleotide motif, and 30 had an imperfect dinucleotide motif; one microsatellite had an
imperfect tetranucleotide motif, and one had an imperfect and compound motif (Table 1 ). Sizes of the cloned alleles ranged from 84 to 252 base pairs. A ‘blast’ search of the GENBANK database indicated that all of the primers and the cloned alleles were unique (i.e., not duplicated)
Improving Production of the Eastern Oyster Crassostrea virginica through Coordination of Genetic Improvement Programs, Research, and Technology Transfer Activities
The East Coast Shellfish Growers Association has been actively advocating for continued improvement of breeding infrastructure to support a vibrant and ecologically crucial industry. This white paper acknowledges these efforts and is meant to serve as a paradigm for oyster breeding on the East Coast. The vision is relatively straightforward; however, its execution—like most things—will be fraught with detail and inertia. Yet describing simply the idea without articulating some detail and potential roadblocks would be misleading. Instead, we present a picture of a breeding paradigm as it might play out across the entire range of a species. At this particular time, when there is increasing interest in oyster aquaculture and the breeding that supports it, and with incipient programs emerging in the Northeast and Gulf, this ‘‘plea’’ for a common approach is meant to help unify shellfish breeding
Genomic structure and expression of uncoupling protein 2 genes in rainbow trout (Oncorhynchus mykiss)
Background
Uncoupling protein 2 (UCP2) belongs to the superfamily of mitochondrial anion carriers that dissociate the respiratory chain from ATP synthesis. It has been determined that UCP2 plays a role in several physiological processes such as energy expenditure, body weight control and fatty acid metabolism in several vertebrate species. We report the first characterization of UCP2 s in rainbow trout (Oncorhynchus mykiss). Results
Two UCP2 genes were identified in the rainbow trout genome, UCP2A and UCP2B. These genes are 93% similar in their predicted amino acid sequences and display the same genomic structure as other vertebrates (8 exons and 7 introns) spanning 4.2 kb and 3.2 kb, respectively. UCP2A and UCP2B were widely expressed in all tissues of the study with a predominant level in macrophage-rich tissues and reproductive organs. In fry muscle we observed an increase in UCP2B expression in response to fasting and a decrease after refeeding in agreement with previous studies in human, mouse, rat, and marsupials. The converse expression pattern was observed for UCP2A mRNA which decreased during fasting, suggesting different metabolic roles for UCP2A and UCP2B in rainbow trout muscle. Phylogenetic analysis including other genes from the UCP core family located rainbow trout UCP2A and UCP2B with their orthologs and suggested an early divergence of vertebrate UCPs from a common ancestor gene. Conclusion
We characterized two UCP2 genes in rainbow trout with similar genomic structures, amino acid sequences and distribution profiles. These genes appeared to be differentially regulated in response to fasting and refeeding in fry muscle. The genomic organization and phylogeny analysis support the hypothesis of a common ancestry between the vertebrate UCPs
A first generation integrated map of the rainbow trout genome
Background
Rainbow trout (Oncorhynchus mykiss) are the most-widely cultivated cold freshwater fish in the world and an important model species for many research areas. Coupling great interest in this species as a research model with the need for genetic improvement of aquaculture production efficiency traits justifies the continued development of genomics research resources. Many quantitative trait loci (QTL) have been identified for production and life-history traits in rainbow trout. An integrated physical and genetic map is needed to facilitate fine mapping of QTL and the selection of positional candidate genes for incorporation in marker-assisted selection (MAS) programs for improving rainbow trout aquaculture production. Results
The first generation integrated map of the rainbow trout genome is composed of 238 BAC contigs anchored to chromosomes of the genetic map. It covers more than 10% of the genome across segments from all 29 chromosomes. Anchoring of 203 contigs to chromosomes of the National Center for Cool and Cold Water Aquaculture (NCCCWA) genetic map was achieved through mapping of 288 genetic markers derived from BAC end sequences (BES), screening of the BAC library with previously mapped markers and matching of SNPs with BES reads. In addition, 35 contigs were anchored to linkage groups of the INRA (French National Institute of Agricultural Research) genetic map through markers that were not informative for linkage analysis in the NCCCWA mapping panel. The ratio of physical to genetic linkage distances varied substantially among chromosomes and BAC contigs with an average of 3,033 Kb/cM. Conclusions
The integrated map described here provides a framework for a robust composite genome map for rainbow trout. This resource is needed for genomic analyses in this research model and economically important species and will facilitate comparative genome mapping with other salmonids and with model fish species. This resource will also facilitate efforts to assemble a whole-genome reference sequence for rainbow trout
A Salmonid EST Genomic Study: Genes, Duplications, Phylogeny and Microarrays
Background: Salmonids are of interest because of their relatively recent genome duplication, and their extensive usein wild fisheries and aquaculture. A comprehensive gene list and a comparison of genes in some of the different speciesprovide valuable genomic information for one of the most widely studied groups of fish.Results: 298,304 expressed sequence tags (ESTs) from Atlantic salmon (69% of the total), 11,664 chinook, 10,813sockeye, 10,051 brook trout, 10,975 grayling, 8,630 lake whitefish, and 3,624 northern pike ESTs were obtained in thisstudy and have been deposited into the public databases. Contigs were built and putative full-length Atlantic salmonclones have been identified. A database containing ESTs, assemblies, consensus sequences, open reading frames, genepredictions and putative annotation is available. The overall similarity between Atlantic salmon ESTs and those of rainbowtrout, chinook, sockeye, brook trout, grayling, lake whitefish, northern pike and rainbow smelt is 93.4, 94.2, 94.6, 94.4,92.5, 91.7, 89.6, and 86.2% respectively. An analysis of 78 transcript sets show Salmo as a sister group to Oncorhynchusand Salvelinus within Salmoninae, and Thymallinae as a sister group to Salmoninae and Coregoninae within Salmonidae.Extensive gene duplication is consistent with a genome duplication in the common ancestor of salmonids. Using all of theavailable EST data, a new expanded salmonid cDNA microarray of 32,000 features was created. Cross-specieshybridizations to this cDNA microarray indicate that this resource will be useful for studies of all 68 salmonid species.Conclusion: An extensive collection and analysis of salmonid RNA putative transcripts indicate that Pacific salmon,Atlantic salmon and charr are 94–96% similar while the more distant whitefish, grayling, pike and smelt are 93, 92, 89 and86% similar to salmon. The salmonid transcriptome reveals a complex history of gene duplication that is consistent withan ancestral salmonid genome duplication hypothesis. Genome resources, including a new 32 K microarray, providevaluable new tools to study salmonids
Integration of molecular genetic information into the NCCCWA selective breeding program for rainbow trout
The USDA/ARS National Center for Cool and Cold Water Aquaculture (NCCCWA) in Leetown, West Virginia, is working to integrate molecular genetic technologies into a selective breeding program aimed at the genetic improvement of rainbow trout for aquaculture production efficien- cy. Our multidisciplinary approach aims to incorporate genome information with respect to dis- ease resistance and stress, growth, and reproductive physiology into our selective breeding pro- gram. Selective breeding is based on the hypothesis that sufficient genetic variation exists in broodstock to realize genetic improvement through contributions of superior performing germplasm to future generations. Our associated goal is to develop and transfer improved germplasm and technologies to the aquaculture industry. Our approach to implementing molec- ular information into our breeding program is outlined under three objectives: (a) development of a genetic map to reveal chromosomal locations affecting traits associated with aquaculture pro- duction, (b) use of a candidate gene approach to identify and characterize genes affecting impor- tant aquaculture production traits through functional genomic technologies, and (c) development of bioinformatic strategies to implement genetic mapping and functional genomic information into a selective breeding program
Genetics and genomics - integration of molecular genetics into a breeding program for rainbow trout
At the National Center for Cool and Cold Water Aquaculture (US Department of Agriculture, Ag. Research Service) in Leetown, WV, we have a broodstock development program now entering the second generation of family-based selective breeding using expected breeding values (EBVs). Our major breeding objectives are faster growth and resistance to Flavobacterium psy- chrophilum, the causative agent of bacterial coldwater disease. For these traits we have devel- oped assays to evaluate phenotypic performance. In addition to our breeding program, we are participating in an international collaboration to develop a microsatellite marker linkage map for the rainbow trout with the intent of identifying quantitative trait loci (QTL) and using them in mark- er (MAS) or gene-assisted (GAS) selection. There are several possible approaches with regard to the types and numbers of markers to develop and the strategies and methods for implement- ing the markers in a selective breeding program. This paper describes the choices we made con- cerning QTL identification for traits of high, low, and unknown degrees of heritability. These traits are plasma cortisol response to a crowding stress (h2 = 0.4), feed intake (h2 = 0.1) and resis- tance to F. psychrophilum (0.3<h2<0.4). In order to identify QTL in a relevant commercially important rainbow trout line, we are making crosses from within our resource population. The development of research family crosses, choice of markers for genome scanning, and planned steps to implementation of these results are described
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