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Net superoxide levels: steeper increase with activity in cooler female and hotter male lizards
journal contribution
posted on 2023-05-17, 11:30 authored by Ballen, C, Healey, M, Wilson, M, Tobler, M, Erik WapstraErik Wapstra, Olsson, MEctotherms 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 4ƒnh versus12ƒnh, and scoring their associated activity (inactive versus active basking and foraging). As predicted, long-basking lizards (hereafter ʻhotʼ) 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 ʻcoldʼ) 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.
History
Publication title
Journal of Experimental BiologyVolume
215Issue
5Pagination
731-735ISSN
0022-0949Department/School
School of Natural SciencesPublisher
Company Of Biologists LtdPlace of publication
140 Cowley Rd, Cambridge, CB4 0DL, UKRights statement
Copyright 2012 The Company of Biologists LtdRepository Status
- Restricted