Superoxide dismutase deficiency impairs olfactory sexual signaling and alters bioenergetic function in mice.
Oxidative stress (an overproduction of reactive oxygen species in relation to defense mechanisms) may restrict investment in life history traits, such as growth, reproduction, lifespan, and the production of sexual signals to attract mates. The constraint on sexual signaling by oxidative stress is of particular interest because it has been proposed as a mechanism ensuring that only good-quality males produce the most attractive sexual signals. Despite these predictions, evidence supporting this theory is, at best, equivocal. We used a superoxide dismutase knockout mouse to demonstrate that oxidative stress directly impairs investment in morphological (preputial glands) and molecular (major urinary proteins) components of olfactory signaling essential for mate attraction. By maintaining males in a much more competitive environment than usual for mouse laboratory experiments, we also revealed a range of phenotypes of superoxide dismutase deficiency not observed in previous studies of this mouse model. This range included impaired bioenergetic function, which was undetectable in the control environment of this study. We urge further examination of model organisms in seminatural conditions and more competitive laboratory environments, as important phenotypes can be exposed under these more demanding conditions.
Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, Michael.Garratt@unsw.edu.au.
Michael
M
Garratt
Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences.
Nicolas
N
Pichaud
Centre for Vascular Research and Faculty of Medicine, and.
Elias N
EN
Glaros
Neuromuscular and Regenerative Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney 2052, NSW, Australia.
Anthony John
AJ
Kee
Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences.
Robert C
RC
Brooks
D000818:Animals; D003163:Competitive Behavior / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018384:Oxidative Stress / Q000502:physiology*; D010636:Phenols / Q000378:metabolism; D010936:Plant Extracts / Q000378:metabolism; D012724:Sex Attractants / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D012903:Smell / Q000502:physiology*; D012931:Social Environment; D013482:Superoxide Dismutase / Q000235:genetics* / Q000378:metabolism*; D000072105:Superoxide Dismutase-1; D013731:Territoriality
D010636:Phenols; D010936:Plant Extracts; D012724:Sex Attractants; C501911:antioxidant biofactor AOB; C000606291:Sod1 protein, mouse; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1
Sod1; antioxidant; condition dependence; male–male competition; sexual selection