Maternal dietary carotenoids mitigate detrimental effects of maternal GnRH on offspring immune function in Japanese quail Coturnix japonica

Abstract

Maternal resources deposited in eggs can aff ect the development of several off spring phenotypic traits and result in tradeoff s among them. For example, maternal androgens in eggs may be benefi cial to off spring growth and competitive ability, but detrimental to immunocompetence and oxidative stress. In contrast, maternal antioxidants in eggs may be benefi cial if they mitigate oxidative stress and immunosuppressive eff ects of androgens. We investigated possible interactive eff ects of maternal steroids and carotenoids on aspects of off spring physiology and phenotype, by simultaneously manipulating levels of androgens (via gonadotropin-releasing hormone, GnRH-challenges) and carotenoids (via diet supplementation) in captive female Japanese quail Coturnix japonica during egg laying. Carotenoid supplementation of hens, which elevates yolk concentrations of carotenoid and vitamins A and E, enhanced egg hatching success, off spring survival to age 15 d, and size of the bursa of Fabricius in off spring. In contrast, repeated maternal GnRH challenges, which elevated yolk testosterone concentrations, enhanced off spring neonatal size, but negatively aff ected bursa size. However, interaction among the treatments suggests that the positive eff ect of maternal carotenoid supplementation on plasma bactericidal capacity was mediated by maternal GnRH challenges. Chicks originating from carotenoid-supplemented hens were less immunosuppressed than those originating from carotenoid-supplemented GnRH-challenged hens, which were less immunosuppressed than chicks from GnRH-challenged females not supplemented with carotenoids. Females availability of carotenoid enriched diets allows them to enhance the development of off spring immune system via carotenoids and vitamins deposited in egg yolks and off set detrimental eff ects of androgens deposited by GnRHchallenged females.