Genome‐wide methylation profile following prenatal and postnatal dietary omega‐3 fatty acid supplementation in pigs

Abstract

The objective of this study was to determine how prenatal and postnatal dietary omega-3 fatty acids alter white blood cell (leukocyte) DNA methylation of offspring. Fifteen gilts (n = 5 per treatment) were selected from one of three treatments: (i) control diet throughout gestation, lactation and nursery phase (CON); (ii) algal omega-3 fatty acid supplementation enriched in EPA and DHA (Gromega ) fed throughout gestation, lactation and nursery phase (Cn3); or (iii) Gromega supplementation maternally, during gestation and lactation only, and control diet during the nursery phase (Mn3). At 11 weeks of age and after 8 weeks of post-weaning nursery feeding, buffy coat genomic DNA was subjected to methyl CpG binding protein sequencing. The methylation enriched profile mapped to 26% of the porcine genome. On chromosome 4, a 27.7-kb differentially methylated region downstream of RUNX1T1 was hypomethylated in the Mn3 and Cn3 groups by 91.6% and 85.0% respectively compared to CON pigs. Conversely, hypermethylation was detected in intergenic regions of chromosomes 4 and 12. Regulatory impact factor and differential hubbing methods were used to identify pathways that were coordinately regulated by methylation due to feeding EPA and DHA during pregnancy. Despite limited ability to detect differential methylation, we describe methods that allow the identification of coordinated epigenetic regulation that could not otherwise be detected from subtle single locus changes in methylation. These data provide evidence of novel epigenetic regulation by maternal and early life supplementation of omega-3 fatty acids that may have implications to growth and inflammatory processes.

Identification of putative regulatory regions and transcription factors associated with intramuscular fat content traits

“…A recent study reported that RUNX1T1 is an inhibitor of brown adipogenesis (associated with a lean and healthy phenotype), which was associated with obesity and suggested that the miRNAs that downregulates this TF could be part of novel therapeutics to increase BAT (brown adipose tissue) in humans [ 54 ]. RUNX1T1 has been also implicated in epigenetic regulation as demonstrated in genome-wide methylation study following prenatal and postnatal dietary omega-3 fatty acid supplementation in pigs, which was differentially methylated between the treatments [ 55 ].…”

Epigenetic DNA Methylation Mediating Octopus vulgaris Early Development: Effect of Essential Fatty Acids Enriched Diet

“…These results have been demonstrated for a diet-sensitive period in the paralarvae of O. vulgaris at around 20 dph and for an effect of LC-PUFA supplementation over the methylation profiles. Despite there are no previous studies correlating this type of dietary supplementation with changes in methylation in invertebrates, the addition of LC-PUFA has shown a global effect over the levels of DNA methylation (Boddicker et al, 2016) and an impact over regulator regions of specific genes (Ma et al, 2016) in vertebrates (well-known in Mus musculus, Rattus norvegicus and Sus scrofa ). The implication of fatty acids on the methylome landmark is well-known but the mechanism behind this effect and their targets are still under study (see Burdge and Lillycrop, 2014 for review).…”

Stress and the HPA Axis: Balancing Homeostasis and Fertility

“…Maternal stress in other mammals has also been linked to adapted fetal outcomes. For example, heat stress during gestation in pigs altered back-fat depth and elevated circulating insulin in offspring later in life [ 110 ]. In utero exposure to heat stress also influenced the thermoregulation of offspring [ 111 ].…”