The Science Seminar Series: April 15, 2010
Life in the cold: adaptations in Antarctic fish.
Carl Whittington , Graduate Student
Department of Biology
Florida State University
Time: 4:00 -5:00pm
Animals in the Southern Ocean face a uniquely cold and stable environment. A group of Antarctic fish, the Notothenioids, has a suite of adaptations to deal with life in below freezing waters. Temperature affects an organism's physiology at all levels of biological organization. Marine ectotherms (fish) are especially sensitive to habitat temperature as their body temperatures are generally identical to the water they are breathing. Over evolutionary time, species adapt to a thermal environment through adjustments at the molecular level in order to maintain a certain level of performance. Research on enzymes has demonstrated that these adjustments in protein sequence, leading to thermal adaptation and conservation of function, typically are remote from the protein active site. Studies of parvalbumin may allow extension of the knowledge gained through research on enzymes to a non-catalytic protein. In muscle, parvalbumin acts as an intra-cellular calcium buffer allowing faster contraction/relaxation cycles. Optimal muscle performance at physiological temperature is critical to a fish's fitness. Conservation of function has previously been demonstrated in parvalbumins from polar and temperate fish. Parvalbumin from the Antarctic fish, Gobionotothen gibberifrons, provides a template structure to investigate the molecular and structural basis of cold-adaptation in parvalbumins from Notothenioids.