Betaine has been widely used in animal and human nutrition to promote muscle growth and performance, yet it remains unknown whether maternal betaine supplementation during gestation affects the metabolic characteristics of neonatal skeletal muscles. In the present study, feeding sows with betaine-supplemented diets throughout gestation significantly up-regulated the expression of mtDNA-encoded OXPHOS genes including COX1, COX2 and ND5, in the muscle of newborn piglets, which was associated with enhanced mitochondrial COX enzyme activity. Concurrently, maternal betaine supplementation increased plasma betaine concentration and muscle expression of methyl transfer enzymes, BHMT and GNMT in offspring piglets. Nevertheless, Dnmt3a was down-regulated at the level of both mRNA and protein, which was associated with hypomethylated mtDNA D-loop region. These results suggest that maternal betaine supplementation during gestation enhances expression of mtDNA-encoded genes through D-loop DNA hypomethylation in skeletal muscle of newborn piglets.
Jia, Y., et al., Maternal betaine supplementation during gestation enhances expression of mtDNA-encoded genes through D-loop DNA hypomethylation in skeletal muscle of newborn piglets. J Agric Food Chem, 2015.