Gaëlle Van Dijk
ProjectHeritability of antioxidant capacity in threespine stickleback Gasterosteus aculeatus
Several trade-offs are associated with breeding mechanisms in which carotenoids allocation and oxidative stress management might play a role. Indeed, carotenoids responsible of nuptial coloration are also antioxidants and immunostimulants and the production of reactive oxygen species rapidly increase during the courtship and the parental care which are energetically costly. Male threespine sticklebacks Gasterosteus aculeatus who display a carotenoid-based nuptial coloration were disposed in large pools to differentiate aggressive male from dominated ones. In order to test heritability of oxidative stress management, 17 females have been used for two crossings, each one with an aggressive male and with a dominated. Skin carotenoid content, metabolic capacities and oxidative status corrected for body size will be examined to establish differences between aggressive and dominated males and similarities between parents and offspring. We expect to observe high level of skin carotenoid content, low level of oxidative damage (lipid peroxidation, DNA and protein oxidation) and better metabolic capacities in aggressive males than in dominated ones. We also expect to obtain similarities in ability to resist oxidative stress between parents and offspring which may demonstrate heritability of this physiological trait. Such results may prove genetic benefits through mate choice by gravid females in favour of aggressive and brightly colored males which provide superior health and higher survival of their offspring.