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

Journal Article


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."

Authors


  •   Ballen, Cissy (external author)
  •   Healey, Mo (external author)
  •   Mark R Wilson
  •   Tobler, Michael (external author)
  •   Dr Erik Wapstra, Erik (external author)
  •   Olsson, Mats M.

Publication Date


  • 2012

Citation


  • Ballen, C., Healey, M., Wilson, M., Tobler, M., Wapstra, E. & Olsson, M. (2012). Net superoxide levels: steeper increase with activity in cooler female and hotter male lizards. The Journal of Experimental Biology, 215 (5), 731-735.

Scopus Eid


  • 2-s2.0-84863418656

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/4585

Has Global Citation Frequency


Number Of Pages


  • 4

Start Page


  • 731

End Page


  • 735

Volume


  • 215

Issue


  • 5

Place Of Publication


  • United Kingdom

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."

Authors


  •   Ballen, Cissy (external author)
  •   Healey, Mo (external author)
  •   Mark R Wilson
  •   Tobler, Michael (external author)
  •   Dr Erik Wapstra, Erik (external author)
  •   Olsson, Mats M.

Publication Date


  • 2012

Citation


  • Ballen, C., Healey, M., Wilson, M., Tobler, M., Wapstra, E. & Olsson, M. (2012). Net superoxide levels: steeper increase with activity in cooler female and hotter male lizards. The Journal of Experimental Biology, 215 (5), 731-735.

Scopus Eid


  • 2-s2.0-84863418656

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/4585

Has Global Citation Frequency


Number Of Pages


  • 4

Start Page


  • 731

End Page


  • 735

Volume


  • 215

Issue


  • 5

Place Of Publication


  • United Kingdom