Placental Transcriptome Adaptations to Maternal Nutrient Restriction in Sheep.

Placental development is modified in response to maternal nutrient restriction (NR), resulting in a spectrum of fetal growth rates. Pregnant sheep carrying singleton fetuses and fed either 100% ( = 8) or 50% (NR; = 28) of their National Research Council (NRC) recommended intake from days 35-135 of pregnancy were used to elucidate placentome transcriptome alterations at both day 70 and day 135. NR fetuses were further designated into upper (NR NonSGA; = 7) and lower quartiles (NR SGA; = 7) based on day 135 fetal weight.

Effect of maternal nutrient restriction on expression of glucose transporters (SLC2A4 and SLC2A1) and insulin signaling in skeletal muscle of SGA and Non-SGA sheep fetuses.

Maternal nutrient restriction (NR) causes small for gestational age (SGA) offspring, which are at higher risk for accelerated postnatal growth and developing insulin resistance in adulthood. Skeletal muscle is essential for whole-body glucose metabolism, as 80% of insulin-mediated glucose uptake occurs in this tissue. Maternal NR can alter fetal skeletal muscle mass, expression of glucose transporters, insulin signaling, and myofiber type composition.

Lipid metabolism is altered in maternal, placental, and fetal tissues of ewes with small for gestational age fetuses†.

Nutrient restriction (NR) has the potential to negatively impact birthweight, an indicator of neonatal survival and lifelong health. Those fetuses are termed as small for gestational age (SGA). Interestingly, there is a spectral phenotype of fetal growth rates in response to NR associated with changes in placental development, nutrient and waste transport, and lipid metabolism.

Development of a surgical procedure for removal of a placentome from a pregnant ewe during gestation.

Background: In recent decades, there has been a growing interest in the impact of insults during pregnancy on postnatal health and disease. It is known that changes in placental development can impact fetal growth and subsequent susceptibility to adult onset diseases; however, a method to collect sufficient placental tissues for both histological and gene expression analyses during gestation without compromising the pregnancy has not been described. The ewe is an established biomedical model for the study of fetal development.

Effect of maternal nutrient restriction on skeletal muscle mass and associated molecular pathways in SGA and Non-SGA sheep fetuses.

Maternal nutrient restriction causes small for gestational age (SGA) offspring, which exhibit a higher risk for metabolic syndrome in adulthood. Fetal skeletal muscle is particularly sensitive to maternal nutrient restriction, which impairs muscle mass and metabolism. Using a 50% nutrient restriction treatment from gestational day (GD) 35 to GD 135 in sheep, we routinely observe a spectral phenotype of fetal weights within the nutrient-restricted (NR) group.