Participants
Bruce Sidell (20 March 1948 - 8 February 2011)
I am a physiologist/biochemist with longstanding interests in subcellular and biochemical mechanisms of adaptation to cold body temperature in Antarctic fishes. We are particularly interested in features that ensure delivery of oxygen to aerobically-poised tissues and that regulate the capacity of these tissues for oxidative metabolism. During the ICEFISH cruise, I will be engaged in a series of discrete but related activities:
- Heart tissues from as many species of notothenioid fishes as possiblewill be sampled. On board, we will perform tissue extractions andimmunochemical tests to determine whether the intracellularoxygen-binding protein, myoglobin, is produced in hearts of red-bloodedspecies. (Previous work has demonstrated variable expression ofthis protein in one notothenioid family, the white-blooded channichthyidicefishes.)
- In collaboration with Joe Eastman, we will perform perfusions(vascular fills) of the entire vascular system of a subset of capturedfish species. In this work, the blood of the animal is displacedwith a latex compound (Microfil˙), which allows easy visualization of thevascular geometry of tissues. The same fish species will also besampled to determine hematocrit (concentration of red blood cells) andestimation of the activity of mitochondrial marker enzymes in retinaltissue.
- Finally, I will preserve heart and retinal tissues from several fishspecies in fixatives for subsequent electron microscopic examination inour University of Maine laboratory.
The ICEFISH cruise should provide a truly unique opportunity to sample notothenioid species that are found north of the Antarctic Polar Front and to examine physiological and biochemical characteristics that may vary from their relatives, which are found exclusively in more frigid waters surrounding Antarctica.