Submitted to: World Aquaculture Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2004
Publication Date: 3/1/2004
Citation: Rexroad III, C.E. 2004. Applying genomics to salmonid aquaculture. World Aquaculture Society Meeting. p.497.
Technical Abstract: The genome of every species contains the blueprint that guides life's biological processes. Gaining an understanding of genomes, therefore, can give clues to understanding the mechanisms that drive these processes and provide knowledge to manipulate them for a desired outcome. In aquaculture, the tools and technologies associated with genomics are being utilized to facilitate selective breeding programs aimed at the genetic improvement of these species for production efficiency. Desired outcomes include the development of strains which are disease resistant, stress tolerant, fast and efficient growers, and reproductively manageable. Engaging in genome research by and large requires the development of species-specific resources. However, due to the recent evolutionary divergence of the salmonids, many of the tools that have been developed for one species are often useful for another. For instance, many of the genetic markers developed in Atlantic salmon also work for rainbow trout and Artic char, and vice versa. This 'comparative genome' approach is often exploited as genome tools and reagents are very expensive and time consuming to develop. For this reason, genome projects are typically undertaken by academic communities consisting of multiple laboratories (university, government, industry) and include international collaborations. Tools of the genome trade include DNA sequence information, chromosome maps, and large insert libraries. Sequence information is broadly available in GenBank, the national database for DNA sequence information, and there has been a dramatic increase in the amount of sequence information for salmonids. The majority of this information is for rainbow trout and Atlantic salmon and comes from projects aimed at gene discovery. There are many types of chromosome maps which fall into one of two categories, physical maps or genetic maps. Physical maps contain information about the physical structure of chromosomes; genetic maps contain information about how genetic markers are inherited. Chromosome maps have been created or are currently under construction for rainbow trout, Atlantic salmon, Artic char, and Chinook salmon. Large insert libraries are constructed by fragmenting DNA from a species of interest and retaining unique fragments in bacterial cells. The bacterial cells are utilized to replicate the DNA and lend themselves to manipulation in the laboratory. Large insert libraries have been created for many salmonids, including rainbow trout and Atlantic salmon. Many genome tools and technologies have recently become available to salmonid researchers who are interested in genetic improvement for aquaculture. The next steps will be (1) to use these tools to identify genes affecting important aquaculture traits, and (2) to implement that knowledge in selective breeding programs.