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


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

This Article
Right arrow Summary Freely available
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 HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Etienne, R.
Right arrow Articles by Pierce, V.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Etienne, R.
Right arrow Articles by Pierce, V.
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?

Mechanisms of urea tolerance in urea-adapted populations of Drosophila melanogaster

Regine Etienne, Kechener Fortunat and Valerie Pierce*

Department of Biology, College of Staten Island/CUNY, 2800 Victory Boulevard, Staten Island, NY 10314, USA



View larger version (13K):

[in a new window]
  		Fig.1. Genetic relationships of experimental (MX) and control (UU) populations. Each pair of populations sharing the same subscript number is descended from the same stock population. Selected flies have been reared on 300mmoll-1 food during the larval period for over 100 generations.

 


View larger version (23K):

[in a new window]
  		Fig.2. Effect of larval presence on amount of urea in food. Experimental groups consisted of vials containing either selected larvae, or control larvae or no larvae. 40 larvae were reared in exactly 2ml of urea food per vial. Food was assayed for urea content after larvae pupated, about 1 week later. Values are means ± 1 S.D., N=5 populations per each experimental group.

 


View larger version (20K):

[in a new window]
  		Fig.3. Effect of selection treatment and time on normal food on urea loss. After rearing on 300mmoll-1 urea food, larvae were switched to normal food or urea food. The zero time point represents larvae switched to urea food as a control for the effect of handling. Hemolymph urea concentrations decrease with increasing time on normal food. The rate of urea loss is significantly greater in the controls than in the selected larvae (10.4mmoll-1h-1 versus 7.0mmoll-1h-1, respectively; values are means ± 1 S.D., N=5, ANCOVA, P<0.001). Note that under a diffusion model, the higher rate of urea loss in the controls can be explained by their higher urea concentration gradient (see text).

 


View larger version (22K):

[in a new window]
  		Fig.4. Effect of selection treatment and time on urea food on urea uptake. After rearing on normal food, larvae were switched to 300mmoll-1 urea food or normal food. The zero time point represents larvae switched to normal food, who thus had no exposure to urea. Hemolymph urea concentrations increase with increasing time on urea food. The rate of urea uptake is significantly greater in the controls than in the selected larvae (8.98mmoll-1h-1 versus 7.12mmoll-1h-1, respectively; values are means ± 1 S.D., N=5, ANCOVA, P<0.029).

 

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 2001