Maternal Diet During Pregnancy Induces Transcriptomic and Epigenomic Changes in Fetal Tissues in Sheep

Research in human, mouse, and livestock has shown that some supplements of the maternal diet during pregnancy impact postnatal progeny phenotypes such as body composition, insulin sensitivity, and health traits. However, there is limited data on the influence of maternal diet on epigenetic modifications and gene expression in sheep and cattle. Therefore, the objective of this study was to investigate the impact of different maternal diet energy sources on the expression of imprinted genes in fetuses in sheep and offspring in beef cattle. In the sheep experiment, ewes were naturally bred to a single sire and from d 67± 3 of gestation until necropsy (d 130 ± 1), they were fed one of three diets of alfalfa haylage (HY; fiber), corn (CN; starch), or dried corn distiller’s grains (DG; protein, fat). A total of 26 fetuses were removed from the dams and longissimus dorsi, semitendinosus, perirenal adipose depot, and subcutaneous adipose depot tissues were collected for expression and DNA methylation analyses. Expression analysis of nine imprinted genes and three DNA methylatransferase (DNMTs) genes showed significant effects of the different maternal diets on the expression of these genes. Then, DNA methylation analysis of IGF2R that showed significant differential methylation between the diet groups in sheep. Thus, results of this study provide an evidence of association between maternal nutrition during pregnancy and transcriptomic and epigenomic alterations of imprinted genes and DNMTs in the fetal tissues.