Marine Ecological Genomics and Adaptation Group (MEGA)

photo: MEGA Lab Staff

The Marine Ecological Genomics and Adaptation (MEGA) group is part of the Molecular Genetics Laboratory (MGL) at the Pacific Biological Station. The MEGA group integrates molecular biology, immunogenetics, ecology and high throughput transcriptional profiling to enhance our understanding of adaptation at the molecular level.

For over 15 years, this group has been at the forefront of research on one of the premiere adaptive genes found in vertebrates, the major histocompatibility complex (MHC), having identified and characterized numerous novel MHC genes in salmon and Atlantic cod. We have accumulated the largest MHC databases for any non-human vertebrate, with over 40,000 coho, 50,000 sockeye, and xxx chinook salmon genotyped for MHC class I and II genes. This research has identified strong adaptive differentiation among populations and uncovered MHC associations with disease susceptibility, kin recognition systems, and environmental bacterial complexity. Furthermore, we have combined the power of adaptive MHC variation and neutral variation of microsatellite loci in the Genetic Stock Identification (GSI) program, a fundamental application of the MGL. GSI has enabled the implementation of real-time stock-based salmon management and has greatly enhanced our knowledge of stock-specific patterns of migration in the Pacific Ocean.

In 2004 the program expanded to include high throughput transcriptional profiling using the salmonid cDNA microarrays produced through the Genomic Research on Atlantic Salmon Project (GRASP) at the University of Victoria (Koop and Davidson). Through this expansion, we are building a better understanding of dynamic phenotypic adaptation of wild salmon populations. Specifically, we are applying microarrays to research adaptive responses to stress (temperature, fishing/handling, density) and disease (IHNV and others), and the physiology of migration. Moreover, we are conducting large scale ecological genomics studies on wild caught salmon in a multidisciplinary program that integrates GSI, radio-tagging, classical physiology and functional genomics to assess the links between physiological condition, migratory behaviour, and fate.

Shifting climate regimes have negatively impacted many aquatic species in the Pacific Northwest and hampered the ability of current management models to predict stock escapements. One major goal of the MEGA program is to better understand variation in the physiological condition, or health, of individuals within our wild stocks, and in turn, to discover how the conditional state of an individual affects its ability to thrive and adapt as the environment changes. We also seek to directly apply the knowledge and tools developed from this program toward sustainable management of aquatic resources through the development of a new generation of management models that integrate information on physiological condition, environmental parameters, and traditional stock assessment data. The program takes a multidisciplinary approach towards attainment of this goal, with close collaboration between molecular geneticists, field biologists, ecologists, physiologists, modellers, and fisheries managers. This program is co-funded by Genome BC, DFO, Pacific Salmon Commission and NSERC.