Sex differences in the relationship between maternal and foetal glucocorticoids in a free-ranging large mammal

Abstract

AbstractMaternal phenotypes can have long-term effects on offspring phenotypes. These maternal effects may begin during gestation, when maternal glucocorticoid (GC) levels may affect foetal GC levels, thereby having an organizational effect on the offspring phenotype. Recent studies have showed that maternal effects may be different between the sexes. How maternal GC levels precisely relate to foetal levels is, however, still not completely understood. Here we related, for the first time in a free-ranging large mammal, the fallow deer (Dama dama), maternal GC levels with foetalin uteroGC levels. We found that foetal GC levels were positively associated with maternal GC levels, but only in females. These findings highlight sex differences, which may have evolved to optimize male growth at the cost of survival.