Degree Name

MS (Master of Science)

Program

Biology

Date of Award

5-2016

Committee Chair or Co-Chairs

Lev Yampolsky

Committee Members

Joe Bidwell, Karl Joplin

Abstract

Freshwater zooplankton crustacean Daphnia frequently face strong temperature fluctuations in its natural environment, which necessitates adaptive plastic responses. This study focuses on changes in lipid peroxidation and total oxidative capacity in Daphnia tissues in response to long-term and short-term temperature changes.

Long-term acclimation to 28ºC helped Daphnia survive longer at lethally high temperatures. This difference, however, was not accompanied by changes in lipid peroxidation, indicating that it isn’t a good measure of damage or predictor of temperature tolerance.

On the other hand, total oxidation capacity was lower 28ºC- than in 18ºC-acclimated Daphnia, suggesting that acclimation resulted in higher amounts of antioxidants in Daphnia tissues. Exposure to hypoxia, known to up-regulate antioxidant pathways in Daphnia, further elevated heat tolerance in 28ºC- acclimated individuals. Yet, manipulations of glutathione, an important antioxidant, while predictably affecting oxidative capacity, didn’t influence heat tolerance in Daphnia, suggesting that other antioxidants may play a significant role in it.

Document Type

Thesis - Open Access

Copyright

Copyright by the authors.

Included in

Biology Commons

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