Sexually dimorphic impact of preconceptional and gestational exposure to a real-life environmental chemical mixture (biosolids) on offspring growth dynamics and puberty in sheep.

Humans are ubiquitously exposed to complex mixtures of environmental chemicals (ECs). This study characterised changes in post-natal and peripubertal growth, and the activation of the reproductive axis, in male and female offspring of sheep exposed to a translationally relevant EC mixture (in biosolids), during pregnancy. Birthweight in both sexes was unaffected by gestational biosolids exposure. In contrast to females (unaffected), bodyweight in biosolids males was significantly lower than controls across the peripubertal period, however, they exhibited catch-up growth eventually surpassing controls. Despite weighing less, testosterone concentrations were elevated earlier, indicative of early puberty in the biosolids males. This contrasted with females in which the mean date of puberty (first progesterone cycle) was delayed. These results demonstrate that developmental EC-mixture exposure has sexually dimorphic effects on growth, puberty and the relationship between body size and puberty. Such programmed metabolic/reproductive effects could have significant impacts on human health and wellbeing. • Puberty was delayed in female offspring of gestational biosolids exposed sheep. • Testicular activation was advanced in male offspring of biosolids exposed sheep. • Maternal biosolid exposure did not affect birthweight of male and female lambs. • Male offspring of biosolids exposed mothers weighed less prior to adulthood. • Maternal biosolid exposure had no impact on bodyweight of female lambs. [ABSTRACT FROM AUTHOR]