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Cracking the oyster's code: International team of scientists finds adaptations to stress in oyster genome

Cracking the oyster's code: International team of scientists finds adaptations to stress in oyster genome

When it comes to stress, oysters know how to deal. The tough-shelled mollusks can survive temperature fluctuations, toxic metals and exposure to air, and a new study of their genetic makeup is helping to explain how. An international team of scientists, including the University of Delaware’s Patrick M. Gaffney, professor of marine biosciences, sequenced the genome of the Pacific oyster, Crassostrea gigas, in a Nature paper published on Sept. 19.

Their analysis revealed that the oysters have unusually high numbers of genes linked to coping with harsh, dynamic environments. For example, oysters have 88 genes for heat shock — five times more than humans — that help them handle temperatures up to 120 degrees Fahrenheit when hit by direct sunlight during low tide.

The oysters are also aided by an abundance of genes that combat toxic chemicals, defend against air exposure, withstand low-salinity surroundings and bolster immune response to pathogens. Forty-eight genes code to prevent apoptosis, or the daily death of cells in an organism, compared with only eight such genes in humans, the researchers found.

The oyster was the first bivalve genome to be sequenced, providing a reference to researchers worldwide for future studies in molluscan biology and evolution.