"A three-foot-diameter hole needs to be drilled through about seven feet of ice, and then a heated dive hut must be placed over the newly drilled hole in order to prevent it from freezing over -- and to keep the divers happy when they surface out of the seawater, which is at a temperature of minus one degree Celsius," she says.
Pasqualone has been assessing the worms' physiological and biochemical responses as they acclimate to an increase in environmental temperature from -1.5 degrees C to 4 degrees C in laboratory experiments. Additional experiments are under way in Marsh's lab at UD's Hugh R. Sharp Campus in Lewes.
For this project, the Marsh laboratory is focusing on identifying epigenetic changes in DNA methylation in these worms -- in other words, how the environment is influencing the worms' genetic code. DNA methylation is a process in animals and plants where environmental signals are "imprinted" on genes in a genome by chemical modification of cytosineone of the bases of the DNA codeto 5'-methyl-cytosine. By tracking changes in metabolic activity and locating genes where methylation changes are active, the scientists will be able to pinpoint the types of genes involved in the temperature acclimation process.
Marsh says he hopes the results of the study will shed light on the ability of some Antarctic species to survive current levels of ocean warming.
"The coastal waters around Antarctica have been at very stable temperatures for millions of years," Marsh says. "This low-temperature environment has led to the evolution of many endemic polar marine species. As global sea-surface temperatures rise, temperatures in Antarctica will also increase. For animals that are used to constant cold conditions, even slight increases in temperature can have large impacts on survival."
Data yielded by the study on how extreme environmental conditions help shape genes and protein
|Contact: Tracey Bryant|
University of Delaware