QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online July 6, 2005
Journal of Experimental Biology 208, 2773-2781 (2005)
Published by The Company of Biologists 2005
doi: 10.1242/jeb.01705

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Shabtay, A. Articles by Arad, Z. Search for Related Content PubMed PubMed Citation Articles by Shabtay, A. Articles by Arad, Z.

Ectothermy and endothermy: evolutionary perspectives of thermoprotection by HSPs

Ariel Shabtay and Zeev Arad^*

Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel

^* Author for correspondence (e-mail: zarad{at}tx.technion.ac.il)

Accepted 23 May 2005

Living organisms respond to heat exposure by selectively expressing heat shock proteins (HSPs). Accumulation of HSPs confers thermotolerance in cell cultures and in ectotherms and is an important component of the heat shock response. This response, however, has not been directly examined in relation to different `thermal states', namely ectothermy vs endothermy. By using avian development as a model system for transition from ectothermy to endothermy, we show that, in contrast to the ectothermic state, in the endothermic state the organism is more resistant to heat but relies less on HSPs as a first-line thermoprotective mechanism. Moreover, intraspecific, real-time, in vivo measurements in genetically diverse fowl strains relate improvement of thermoresistance in endotherms to improved body temperature (T_b) regulation, with a concomitant delay in the expression of HSPs. The time course of this delay and the T_b at which it occurs imply that the ontogenetic and evolutionary pathways leading to improved thermoresistance may have followed two, apparently non-related, parallel routes – cellular and peripheral (non-cellular). In search of other cellular components that differentially participate in the heat shock response, we revealed a significant expression of fatty acid synthase (FAS) in heat-exposed endotherms but not in ectotherms.

Key words: HSP, ectothermy, endothermy, thermotolerance, heat shock, Gallus gallus domesticus

This article has been cited by other articles:

				A. R. A. Villalobos and J. L. Renfro Trimethylamine oxide suppresses stress-induced alteration of organic anion transport in choroid plexus J. Exp. Biol., February 1, 2007; 210(3): 541 - 552. [Abstract] [Full Text] [PDF]

				A. Shabtay and Z. Arad Reciprocal activation of HSF1 and HSF3 in brain and blood tissues: is redundancy developmentally related? Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2006; 291(3): R566 - R572. [Abstract] [Full Text] [PDF]