Genomic and physiological approaches are being used to investigate muscle growth and adaptation in teleost fish. Skeletal muscle fibres are produced during the embryonic, larval and adult stages of the lifecycle. The genetic mechanisms controlling the production of muscle fibres and their subsequent hypertrophy are being studied. Several novel myogenic genes have been discovered and their functions characterised using in vivo and in vitro using primary muscle cultures. Using various models involving body size evolution and temperature adaptation I have shown strong selection for fibre size optimization, with consequences for the life-time production of muscle fibres. Universal scaling laws affecting muscle dimensions and energy metabolism can therefore successfully explain variations in fibre number and fine scale evolutionary patterns of myogenesis between populations and species. Salmonid fish have undergone two whole genome duplications relative to their common ancestor with tetrapods resulting in up to 8 copies (paralogues) of some genes. The role of gene paralogues in the signaling pathways regulating growth is being studied. Other research interests include the molecular mechanisms underlying seasonal temperature acclimation in fish and the consequences for muscle power output and swimming performance. Embryonic stress in zebrafish was shown to have persistent affects on thermal acclimation and myogenesis that persisted to adulthood, even after fish were raised from hatching at a common temperature. The mechanisms are currently under investigation at the genomic, tissue and whole animal levels.

• Comparative genomics
• Muscle physiology
• Animal evolution
• Development
• Aquaculture

Previous research has shown how muscle growth patterns influence flesh quality, particularly texture and processing characteristics in a wide range of fish of commercial importance (salmon, cod, halibut). Current research involves the identification of molecular biomarkers of growth with particular reference to the IGF-mTor-Akt signaling pathway. We are also investigating genetic polymorphisms in genes responsible for flesh quality traits in farmed fish. The research has applications in fish nutrition and in breeding and is being carried out in collaboration with leading companies in the aquaculture industry.