411 Awardee Talk: Fetal Programming and Molecular Characterization of the Skeletal Muscle Development in Ruminants

Abstract

Abstract Three experiments were developed aiming to investigate the effects of maternal nutrition on the skeletal muscle development and metabolism of the offspring. The first study was designed to evaluate the protein restriction during mid-gestation on the skeletal muscle growth of beef cattle offspring. Our results revealed that maternal protein restriction at this stage of gestation caused a decreased number of muscle fibers in the offspring. The second and third studies aimed to elucidate the effects of maternal feed restriction during different stages of gestation on the transcriptome and proteome profile in the skeletal muscle of the newborn. In these experiments, pregnant goats were feed-restricted (at 50% maintenance requirements) either during the first or second half of gestation. Transcriptome analysis revealed that feed restriction at first half of gestation upregulated genes involved with the maintenance of satellite cells, and fatty acid oxidation in skeletal muscle of the newborn. On the other hand, restriction at the second half of gestation upregulated genes related with the balance of glucose metabolism, in addition to protective mechanisms against the oxidative stress in the skeletal muscle of the newborn. Through the proteomic analysis, we observed enriched biological processes (BP) and signaling pathways (SP) related with the energy-investment phase of glycolysis, in addition to the increase in the usage of glycogen and fatty acids storages in the skeletal muscle of the newborn due to feed restriction at the first half of gestation. We also observed that when feed restriction occurs at second half of gestation there is an enrichment in BP and SP associated with the energy-generation phase of glycolysis, and an enhancement in the biosynthesis of glutamine in skeletal muscle of the newborns. Overall, the results of these studies bring insights that help to develop nutritional strategies during early life development aiming to improve postnatal performance.