Plasticity of Fish Muscle Phenotype in Response to a Thermally Variable Environment An Ecophysiological Study of Fundulus grandis Eurythermal Performance from a Protein Perspective
Date of Award
2010
Document Type
Thesis
Degree Name
Bachelors
Department
Natural Sciences
First Advisor
Demski, Leo
Keywords
Ecophysiology, Fundulus grandis, Thermal Acclimation, Fish, Thermostability
Area of Concentration
Biochemistry
Abstract
Temperature has a profound effect on biological processes. Enzyme kinetics and macromolecular structure are no exception to thermodynamic laws. Therefore, acute, seasonal and evolutionary variation in environmental temperature poses a serious challenge to organisms whose body temperatures fluctuate with that of the environment. There are myriad adaptations that allow such organisms to cope with such challenges, including the plasticity of phenotype in response to the thermal environment. In fish, a thermal acclimation response has evolved that allows locomotory muscle to acclimate to seasonal changes in temperature. Some fish, such as Fundulus grandis, however, persist in environments such as estuaries that exhibit severe fluctuation in temperature on time scales shorter than the acclimation response can be completed. These fish must utilize other adaptations that allow them to reproduce, avoid predation and forage in spite of such harsh abiotic conditions. It was hypothesized that the acute temperature insensitivity of this species obviates the need for the typical acclimation response employed by other fish. To test this hypothesis, components of the acclimation response were examined in this species and compared to another eurythermal fish from a less acutely variable environment, the goldfish Carassius auratus. ATPase activities and thermostability of glycolytic muscle myosin from these fish was not successfully examined. As these were the primary indicators of the acclimation response utilized in this study, it was not possible to fully address the hypothesis. Electrophoresis studies, however, revealed that Fundulus grandis most likely do not alter the expression of myosin isoforms in response acclimation temperature, a typified acclimation response across many groups. Carassius auratus, on the other hand, do alter the ratio of myosin light chain isoforms in response to acclimation temperature and do not alter expression of myosin heavy chain isoforms severely in the temperature range tested, both new findings. The inability to fully assess the extent of the acclimation response in Fundulus grandis also prevented analysis of evolutionary theories regarding the effect of local environmental conditions on selective pressures of the acclimation response and its evolutionary lability.
Recommended Citation
Dayan, David, "Plasticity of Fish Muscle Phenotype in Response to a Thermally Variable Environment An Ecophysiological Study of Fundulus grandis Eurythermal Performance from a Protein Perspective" (2010). Theses & ETDs. 4246.
https://digitalcommons.ncf.edu/theses_etds/4246
Rights
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