Advanced

Net superoxide levels: steeper increase with activity in cooler female and hotter male lizards

Ballen, Cissy; Healey, Mo; Wilson, Mark; Tobler, Michael LU ; Wapstra, Erik and Olsson, Mats (2012) In Journal of Experimental Biology 215(16). p.731-735
Abstract
Ectotherms increase their body temperature in response to ambient heat, thereby elevating their metabolic rate. An often inferred consequence of this is an overall upregulation of gene expression and energetic expenditure, and a concomitant increased production of reactive oxygen species (e.g. superoxide) and, perhaps, a shortened lifespan. However, recent work shows that this may be a superficial interpretation. For example, sometimes a reduced temperature may in fact trigger up-regulation of gene expression. We studied temperature and associated activity effects in male and female Australian painted dragon lizards (Ctenophorus pictus) by allowing the lizards to bask for 4 h versus 12 h, and scoring their associated activity (inactive... (More)
Ectotherms increase their body temperature in response to ambient heat, thereby elevating their metabolic rate. An often inferred consequence of this is an overall upregulation of gene expression and energetic expenditure, and a concomitant increased production of reactive oxygen species (e.g. superoxide) and, perhaps, a shortened lifespan. However, recent work shows that this may be a superficial interpretation. For example, sometimes a reduced temperature may in fact trigger up-regulation of gene expression. We studied temperature and associated activity effects in male and female Australian painted dragon lizards (Ctenophorus pictus) by allowing the lizards to bask for 4 h versus 12 h, and scoring their associated activity (inactive versus active basking and foraging). As predicted, long-basking lizards (hereafter ‘hot’) showed heightened activity in both sexes, with a more pronounced effect in females. We then tested for sex-specific effects of basking treatment and activity levels on the increase in net levels of superoxide. In males, short-baskers (hereafter ‘cold’) had significantly more rapidly decreasing levels of superoxide per unit increasing activity than hot males. In females, however, superoxide levels increased faster with increasing activity in the cold than in the hot basking treatment, and females earlier in the ovarian cycle had lower superoxide levels than females closer to ovulation. In short, males and females differ in how their levels of reactive oxygen species change with temperature-triggered activity. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
reactive oxygen species, thermoregulation, lizard
in
Journal of Experimental Biology
volume
215
issue
16
pages
731 - 735
publisher
The Company of Biologists Ltd
external identifiers
  • scopus:84863418656
ISSN
1477-9145
DOI
10.1242/​jeb.062257
project
Costs of the immune system and maternal effects
language
English
LU publication?
yes
id
d1ab0cb0-df64-443e-985c-a467f690acc9 (old id 3050482)
date added to LUP
2012-09-06 14:46:03
date last changed
2017-01-01 03:23:32
@article{d1ab0cb0-df64-443e-985c-a467f690acc9,
  abstract     = {Ectotherms increase their body temperature in response to ambient heat, thereby elevating their metabolic rate. An often inferred consequence of this is an overall upregulation of gene expression and energetic expenditure, and a concomitant increased production of reactive oxygen species (e.g. superoxide) and, perhaps, a shortened lifespan. However, recent work shows that this may be a superficial interpretation. For example, sometimes a reduced temperature may in fact trigger up-regulation of gene expression. We studied temperature and associated activity effects in male and female Australian painted dragon lizards (Ctenophorus pictus) by allowing the lizards to bask for 4 h versus 12 h, and scoring their associated activity (inactive versus active basking and foraging). As predicted, long-basking lizards (hereafter ‘hot’) showed heightened activity in both sexes, with a more pronounced effect in females. We then tested for sex-specific effects of basking treatment and activity levels on the increase in net levels of superoxide. In males, short-baskers (hereafter ‘cold’) had significantly more rapidly decreasing levels of superoxide per unit increasing activity than hot males. In females, however, superoxide levels increased faster with increasing activity in the cold than in the hot basking treatment, and females earlier in the ovarian cycle had lower superoxide levels than females closer to ovulation. In short, males and females differ in how their levels of reactive oxygen species change with temperature-triggered activity.},
  author       = {Ballen, Cissy and Healey, Mo and Wilson, Mark and Tobler, Michael and Wapstra, Erik and Olsson, Mats},
  issn         = {1477-9145},
  keyword      = {reactive oxygen species,thermoregulation,lizard},
  language     = {eng},
  number       = {16},
  pages        = {731--735},
  publisher    = {The Company of Biologists Ltd},
  series       = {Journal of Experimental Biology},
  title        = {Net superoxide levels: steeper increase with activity in cooler female and hotter male lizards},
  url          = {http://dx.doi.org/10.1242/​jeb.062257},
  volume       = {215},
  year         = {2012},
}