Project Update July 2008
Broodstock Development
The CGP has established family-based breeding programs in Newfoundland and New Brunswick / New Hampshire. The first three major spawning seasons have been completed. Between the fish being evaluated as part of the CGP and surplus cod, over 100,000 juvenile cod were placed in sea cages in the Atlantic region by November 2006. An estimated 94,000 more were available for transfer to sea cages by the end of 2007. At present juveniles from the third spawning season are being reared at the Ocean Sciences Centre, Memorial University of Newfoundland and at the newly constructed hatchery at the Huntsman Marine Science Centre in St. Andrews, NB.
Once CGP family fish reach an average weight of 15 grams, they are tagged and assessed. Throughout the spring and summer, staff at rearing facilities track family performance related to growth, survival and the overall health of the progeny. Significant variation in growth between the families has been observed, and the heritability estimates are high, indicating that the breeding programs will be successful at improving growth rates of cod for aquaculture.
Genomics
The CGP has dramatically improved the availability of genomic resources for this species. Within the first 18 months of project inception, 96% of publicly available DNA sequence information for cod was contributed by the CGP. To date, just over 158,000 sequences have been submitted to GenBank – a publicly accessible genetic sequence database.
Sequences are being used within the CGP for gene discovery and the development of gene linked markers. Marker identification has yielded >4,700 “predicted informative” SNPs (single nucleotide polymorphisms) and 150 microsatellite markers. The resources being developed by the CGP will be invaluable for analyzing quantitative trait loci (QTL), identifying genes of potential importance in Canadian cod aquaculture and enabling marker assisted selection (MAS) within cod breeding programs. MAS will enable rapid enhancement of cod broodstock in Canada, and is an approach that has been the cornerstone of recent advancements realized in other animal production systems including beef, pork and chicken production.
Other Project Activities
The CGP includes ongoing studies of the stress response in cod and performance differences between haemoglobin genotypes, as well as studies that examine the cod’s response to thermal challenges and immunogenic stimuli that simulate disease challenges. Results have shown that there is considerable variation among cod families with respect to their tolerance to elevated temperatures and stress; thus, there is great potential to select fish that will perform well under variable aquaculture conditions. The project has also identified many genes that have altered expression when cod are exposed to immunogenic stimuli. The majority of these genes will be represented on a ‘gene chip’ or microarray that is currently being generated.
The CGP also includes research on ethical, economic, environmental, legal and social issues associated with the science of genomics (GE3LS). The GE3LS research team is developing solution-oriented legal and policy options regarding: legal ownership of commercially valuable research results, the status of elite cod broodstock under Canadian environmental law and Canada’s international obligations, and ethical and legal options regarding benefit sharing and improved methods of consultation with the affected publics.