Atlantic salmon expressing transgenic growth hormone experienced
numerous changes to their cardiorespiratory system.
Atlantic salmon (Salmo salar).
Growth hormone gene from chinook salmon (Oncorhynchus
tshawytscha). Gene expression was controlled using the antifreeze
protein promoter from ocean pout (Zoarces americanus).
Goal of These Studies:
Compare the growth and physiology of the transgenic salmon to non-GM
salmon from the same stock.
Results of These Studies:
The transgenic fish gained weight 2-3 times more quickly but had a lower
condition factor, meaning they were lighter than (older) non-GM fish of
The transgenic fish developed into smolt (which in the wild precedes
migration to the ocean) within their first year of life, whereas the
non-GM fish required two years to make this transition.
The transgenic fish consumed oxygen at a higher rate than size-matched
non-GM fish. Stevens et al. (1998) measured a 70% increase in respiration
for one strain, while Deitch et al. (2006) measured a 20% increase for
a different strain.
The GM fish had elevated levels of adrenaline and noradrenaline in their
blood (70% higher).
The hearts of the GM fish were 20% larger than size-matched non-GM fish,
and their resting heart rate was 84 beats per minute (GM) versus 73 beats
per minute (non-GM).
Stevens, E. D., A. Sutterlin, and T. Cook (1998). "Respiratory Metabolism
and Swimming Performance in Growth Hormone Transgenic Atlantic Salmon,"
Canadian Journal of Fisheries and Aquatic Sciences vol. 55,
Deitch, E. J., G. L. Fletcher, L. H. Petersen et al. (2006).
"Cardiorespiratory Modifications, and Limitations, in Post-Smolt Growth
Hormone Transgenic Atlantic Salmon Salmo salar," Journal of
Experimental Biology vol. 209, pp. 1310-25.
University of Guelph, Canada; AquaBounty Farms, Canada; Memorial
University of Newfoundland, Canada.
National Research Council of Canada; AquaBounty.
As of 2009, this product is being reviewed by the FDA for commercial use
in the U.S.
Copyright 2009 The Nature