Epigenetics

Gestational Thermal Environment and Maternal Antioxidant Supplementation Interact to Shape the Hepatic DNA Methylome of Iberian Piglets

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Abstract

DNA methylation is one of the most relevant epigenetic mechanisms, playing an important role in (re)programming during early life development, when the epigenome is highly susceptible to external influences. This study analyzed the hepatic DNA methylome profile of Iberian piglets exposed to intrauterine heat stress, and maternal antioxidant supplementation as an intervention strategy. Our aim was to identify differentially methylated CpG sites as potential markers of early developmental reprogramming. The present work was based on two trials: one in which sow gestation took place from November to March (TN: themoneutrality; Taverage = 20.3 ± 2.9ºC) and another from May to September (HS: heat stress; Taverage = 28.2 ± 2.9ºC). A total of 48 Iberian sows were assigned to two dietary groups (n = 24) from day 50 of gestation until weaning: a) control diet: 100 IU/Kg of vitamin E and inorganic minerals (Mn, Zn, Cu, Se) following FEDNA 2013 recommendations; and b) mineral diet: control diet but with a proportion of the inorganic minerals (45-100%) changed to organic minerals to improve absorption. At 21 days, 32 piglets from each trial were slaughtered, selecting small (0.98 ± 0.12 Kg) and large (1.51 ± 0.11 Kg) individuals, equally distributed by maternal diet and sex. The hepatic DNA methylome was analyzed by reduced representation bisulfite sequencing (RRBS) covering overall 2.5 million CpGs of wich 20% reside in promoters, 12% in exons, 38% in introns and 30% in intergenic regions. Of these, at least 440,000 CpGs were common in all groups and further analyzed for differentially methylated CpGs (DMC), defined as ≥ 20% methylation difference and q < 0.01, using the bioinformatic pipeline Bismark-methylKit-genomation. Our results showed that gestational thermal environment and maternal diet condition-dependently influenced the DNA methylation profile of the piglets. The season effect (HS vs TN) was more pronounced in the control diet group (2776 DMCs; 944 hyper- and 1832 hypo-methylation in HS) compared to the mineral diet group (434 DMC; 173 hyper- and 261 hypo-methylation in HS), suggesting that maternal antioxidant supplementation may prevent the DNA methylation changes due to season. In addition, the maternal diet effect (mineral vs control) observed in HS (2539 DMC; 1225 hyper- and 1314 hypo-methylation in mineral diet group) was stronger than detected in TN (405 DMC; 167 hyper- and 238 hypo-methylation in mineral diet group). Functional enrichment analysis revealed that these DMC were associated with genes related to different biological processes including AMPK and PI3K-Akt signaling, cytoskeleton organization, and aldosterone synthesis. Overall, these findings indicate an interaction between maternal antioxidant supplementation and gestational thermal environment that modulates the hepatic methylome of Iberian piglets, with a greater effect of perinatal supplementation during HS trial.

Keywords: 2026

How to Cite:

Vázquez-Ortego, P., Aranguren-Rivas, P., Núñez, Y., García-Cabrero, A., Escudero, R., Sánchez-Esquiliche, F., Gómez-Mateos, G., Trakooljul, N., Murani, E., Óvilo, C., García-Casco, J., Heras-Molina, A. & Muñoz, M., (2026) “Gestational Thermal Environment and Maternal Antioxidant Supplementation Interact to Shape the Hepatic DNA Methylome of Iberian Piglets”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2284589. doi: https://doi.org/10.31274/wcgalp.23600

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