Net superoxide levels: steeper increase with activity in cooler female and hotter male lizards
Författare
Summary, in English
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.
Avdelning/ar
Publiceringsår
2012
Språk
Engelska
Sidor
731-735
Publikation/Tidskrift/Serie
Journal of Experimental Biology
Volym
215
Issue
16
Fulltext
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Dokumenttyp
Artikel i tidskrift
Förlag
The Company of Biologists Ltd
Ämne
- Biological Sciences
Nyckelord
- reactive oxygen species
- thermoregulation
- lizard
Status
Published
Projekt
- Immunoecology
Forskningsgrupp
- Molecular Ecology and Evolution Lab
ISBN/ISSN/Övrigt
- ISSN: 1477-9145