Differential Expression Analysis of Placentae from Overfed/Obese Ewes and Lean Ewes Fed Only to Requirements

Sheep are a relevant biomedical model for studying human pregnancy. Maternal diet plays an important role in providing appropriate nutrients to a fetus and promoting healthy growth and development. In several mammalian species including sheep and humans, obesity during pregnancy predisposes offspring to obesity, insulin resistance, and cardiovascular disease. Obesity among pregnant women in the U.S. is now reported at between 18-38% and is increasing. Gaining an increased understanding of how maternal obesity affects an offspring’s predisposition to obesity and its associated diseases is a priority.

This study investigated how maternal diet alters gene expression in the placenta, the organ responsible for providing maternal nutrients to the developing fetus. The maternal nutrient environment to which the placenta is exposed determines maternal:fetal nutrient exchange and subsequent programming of gene expression patterns in the conceptus. Deviation from a healthy maternal diet results in altered offspring phenotype and leads to predisposition to obesity and other diseases. Differential expression analysis was performed on placental tissue from pregnant ewes fed either a control (100% of requirements) or an obesogenic (150% of requirements) diet. We performed pathway and enrichment analysis on the differentially expressed genes and identified individual genes and broader pathways that are candidates for further investigation.