Maternal age and traits in offspring

摘要

We have investigated the effect of the age at first pregnancy in mice on maternal steroid hormone levels and how these influence the growth and sexual maturation of their pups. We find that early-adolescent and middle-aged pregnant mice have less serum oestradiol and a different pattern of serum testosterone compared with young-adult pregnant mice. Grown offspring of early-adolescent and middle-aged mothers have lower body weight and delayed puberty, and males have smaller reproductive organs than those produced by young adults. Female offspring themselves produce pups whose birthweight depends on the age at pregnancy of their grandmothers. Changes in a female's physiology during ageing can thus alter the growth and reproductive traits not only of her own offspring but also of subsequent generations.