HEIDINGER, B. J.; GRINDSTAFF, J. L.; Indiana University; Indiana University: Effects of experimentally elevated in ovo testosterone exposure on early chick growth and cell mediated immunity in the Japanese quail (Coturnix japonica)

Maternal effects may have profound influences on offspring phenotype. One such effect, the transfer of maternal androgens to eggs, may be an adaptive way for females to enhance offspring growth rates. Early exposure to androgens, however, may also suppress immunity. In this study, we experimentally elevated yolk levels of testosterone in the eggs of Japanese quail (Coturnix japonica) via microinjection prior to incubation. Subsequently, we assessed growth and cell mediated immune function in developing chicks. We predicted that chicks exposed to experimentally elevated testosterone levels would 1) have enhanced post hatching growth rates relative to controls and 2) suppressed cell mediated immunity relative to controls. Contrary to our predictions, there was no influence of testosterone treatment on chick growth or cell mediated immunity. The potential implications of these results are discussed within the context of previous studies on the transfer of maternal androgens to eggs.