spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online July 20, 2007
Journal of Experimental Biology 210, 2649-2656 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.003350
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Folk, D. G.
Right arrow Articles by Gilchrist, G. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Folk, D. G.
Right arrow Articles by Gilchrist, G. W.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Critical thermal maxima in knockdown-selected Drosophila: are thermal endpoints correlated?

Donna G. Folk*, Luke A. Hoekstra and George W. Gilchrist

Department of Biology, College of William and Mary, Williamsburg, VA 23187, USA

* Author for correspondence (e-mail: dgfolk{at}roadrunner.com)

Accepted 2 May 2007

To explore the correlation of traits linked to thermotolerance, we compared three thermal endpoints (knockdown temperature and two critical thermal maxima) among replicate populations of Drosophila melanogaster selected for high, or low, knockdown temperature. The high knockdown flies maintain normal posture and locomotor ability within a knockdown column at temperatures >=40°C, whereas the low knockdown flies fall out of the column at much cooler temperatures (~35°C, on average). The critical thermal maximum (CTmax) for respiratory control in the selected knockdown populations was determined by analyzing CO2 output of individuals during exposure to a temperature ramp (from 30°C to >45°C) and was indicated by an abrupt alteration in the pattern of CO2 release. The CTmax for locomotor function was determined by monitoring activity (concurrent with CO2 analysis) during the temperature ramp and was marked by the abrupt cessation of activity. We hypothesized that selection for high knockdown temperature may cause an upward shift in CTmax, whereas selection for low knockdown may lower CTmax. Correlations among the three thermal endpoints varied between the high and low knockdown flies. Finally, we compared metabolic profiles, as well as Q10 values, among the high and low knockdown males and females during the temperature ramp.

Key words: Drosophila melanogaster, laboratory selection, thermotolerance, knockdown, critical thermal maximum, thermolimit respirometry, metabolic rate, Q10


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?




© The Company of Biologists Ltd 2007