Maternal diet and programming of embryo and fetal development in the mouse

Plasticity is a prominent feature of early development, and is necessary to allow the fetus in utero to adapt to the continual variation in nutrient and oxygen supply it receives from the mother. In contrast to adaptations made in adult life, those made during fetal life tend to become permanent and irreversible (i.e. programmed). This is due to the existence of sensitive periods which are brief windows of growth and development in early life during which there is an increased susceptibility to programming influences (Barker, 1999). Under-nutrition (or other adverse influences) occurring during fetal life or immediately after birth may thus induce developmental plasticity.This study examined the impact of a relatively mild dietary protein restriction in the mouse during pregnancy on the subsequent development of the fetus. The responses of the fetus to the maternal dietary challenge were studied close to the end of gestation (at day 17) using three broadly different approaches. Fetal hepatic tissue was examined for a response to the maternal dietary challenge in terms of global gene expression with the use of Affymetrix micro-arrays. The protein expression profiles of two related proteins were also studied in response to dietary manipulations in fetal liver tissue. Finally, blastocyst stage embryo-transfers were performed in an attempt to elucidate the relative contributions of the early embryo experience versus the ongoing maternal environment to the subsequent fetal growth. Overall, the approaches used suggest that the growth and protein expression of the fetus are altered by maternal dietary manipulation when the challenge is restricted to the pre implantation period of development