Data from: Chronic protein restriction in mice impacts placental function and maternal body weight before fetal growth

Mechanisms of resource allocation are essential for maternal and fetal
survival, particularly when the availability of nutrients is limited. We
investigated the responses of feto-placental development to maternal
chronic protein malnutrition to test the hypothesis that maternal low
protein diet produces differential growth restriction of placental and
fetal tissues, and adaptive changes in the placenta that may mitigate
impacts on fetal growth. C57BL/6J female mice were fed either a
low-protein diet (6% protein) or control isocaloric diet (20% protein). On
embryonic days E10.5, 17.5 and 18.5 tissue samples were prepared for
morphometric, histological and quantitative RT-PCR analyses, which
included markers of trophoblast cell subtypes. Potential endocrine
adaptations were assessed by the expression of Prolactin-related hormone
genes. In the low protein group, placenta weight was significantly lower
at E10.5, followed by reduction of maternal weight at E17.5, while the
fetuses became significantly lighter no earlier than at E18.5. Fetal head
at E18.5 in the low protein group, though smaller than controls, was
larger than expected for body size. The relative size and shape of the
cranial vault and the flexion of the cranial base was affected by E17.5
and more severely by E18.5. The junctional zone, a placenta layer rich in
endocrine and energy storing glycogen cells, was smaller in low protein
placentas as well as the expression of Pcdh12, a marker of glycogen
trophoblast cells. Placental hormone gene Prl3a1 was altered in response
to low protein diet: expression was elevated at E17.5 when fetuses were
still growing normally, but dropped sharply by E18.5 in parallel with the
slowing of fetal growth. This model suggests that nutrients are
preferentially allocated to sustain fetal and brain growth and suggests
the placenta as a nutrient sensor in early gestation with a role in
mitigating impacts of poor maternal nutrition on fetal growth.