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Chaenocephalus aceratus Transcriptome or Gene expression
The Antarctic icefish (Chaenocephalus aceratus) provides several evolutionary models of human disease, including bone mineral loss, lipid storage diseases, and anemia. The ancestral Notothenioids from which the icefish evolved became specialized for a bottom-dwelling lifestyle and as a result lost their swim bladder. In response to changing environmental pressures, body density has been reduced to achieve neutral bouyancy in the absence of a swim bladder. The reduction in body density was accomplished through decreased bone mineralization and the accumulation of low-density lipids in muscle and connective tissue. Icefish have lost the ability to form red blood cells and hemoglobin genes have become pseudo genes. The cost of this disaptation is low due to the high capacity of cold water to dissolve oxygen and adaptive compensatory responses. Comparison with related species lacking these changes provides the opportunity to identify gene pathways and regulatory factors contributing to similar conditions in humans.