Geographic Variation of Freeze Tolerance in the Pacific Chorus frog, Pseudacris regilla
Document Type
Oral Presentation
Campus where you would like to present
SURC 271
Start Date
17-5-2012
End Date
17-5-2012
Abstract
This study is comparing the physiological responses to freezing of Pacific Chorus frogs from a coastal (Mill Creek) site, a central inland (Ellensburg) site, and a high-elevation site on Snoqualmie Pass. Pacific Chorus frogs have an amazing ability to freeze solid during the winter months. They are able to do this because they store massive amounts of glycogen that they break into glucose. Glucose is used for (1) to protect the cells during freezing and (2) to support general metabolism throughout the entire winter. The hypotheses are (1) where frogs would experience colder winters with less snow pack those frogs would produce more glucose and survive freezing to lower temperatures and (2) where frogs would experience longer winters, those frogs will produce more liver glycogen. We collected frogs in the spring from the Mill Creek, Ellensburg, and Snoqualmie Pass areas and housed them until the fall when they had developed their cold tolerance. They were then moved inside to an incubator set at 2°C. In January, the frogs were frozen in a cooling bath down to -2.5°C. Once frozen, the frogs were dissected and liver and thigh were extracted and frozen. Each tissue was later homogenized in acid and then neutralized with a base to extract the glucose and glycogen for measurement. The glucose and glycogen solutions were mixed with a color reagent which forms a colored product in the presence of glucose which was measured with a spectrophotometer. Results from the past three year’s experiments will be presented.
Recommended Citation
Healas, Sara, "Geographic Variation of Freeze Tolerance in the Pacific Chorus frog, Pseudacris regilla" (2012). Symposium Of University Research and Creative Expression (SOURCE). 108.
https://digitalcommons.cwu.edu/source/2012/oralpresentations/108
Additional Mentoring Department
Biological Sciences
Geographic Variation of Freeze Tolerance in the Pacific Chorus frog, Pseudacris regilla
SURC 271
This study is comparing the physiological responses to freezing of Pacific Chorus frogs from a coastal (Mill Creek) site, a central inland (Ellensburg) site, and a high-elevation site on Snoqualmie Pass. Pacific Chorus frogs have an amazing ability to freeze solid during the winter months. They are able to do this because they store massive amounts of glycogen that they break into glucose. Glucose is used for (1) to protect the cells during freezing and (2) to support general metabolism throughout the entire winter. The hypotheses are (1) where frogs would experience colder winters with less snow pack those frogs would produce more glucose and survive freezing to lower temperatures and (2) where frogs would experience longer winters, those frogs will produce more liver glycogen. We collected frogs in the spring from the Mill Creek, Ellensburg, and Snoqualmie Pass areas and housed them until the fall when they had developed their cold tolerance. They were then moved inside to an incubator set at 2°C. In January, the frogs were frozen in a cooling bath down to -2.5°C. Once frozen, the frogs were dissected and liver and thigh were extracted and frozen. Each tissue was later homogenized in acid and then neutralized with a base to extract the glucose and glycogen for measurement. The glucose and glycogen solutions were mixed with a color reagent which forms a colored product in the presence of glucose which was measured with a spectrophotometer. Results from the past three year’s experiments will be presented.
Faculty Mentor(s)
Jason Irwin