Animal welfare

Neonatal piglets exhibit differential gene expression in brain and adrenal tissue associated with maternal resilience to social stress

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Abstract

Several studies have demonstrated that prenatal social stress programs piglet performance, including function of the hypothalamic-pituitary-adrenal (HPA) axis. The modern sow faces increased social stress as the global swine industry has largely transitioned to gestational group-housing, highlighting the need to characterize individual sow response and subsequent programming of her offspring. The objective of this study was to investigate transcriptional profiles of tissues that regulate the HPA-axis (hypothalamus, hippocampus, and adrenal gland) in neonatal piglets born to sows exhibiting maternal resilience or vulnerability to social stress in early gestation. Following confirmation of pregnancy at 25 days of gestation (dg) nulliparous gilts (n=32) and primiparous sows (n=32) were subjected to an acute mixing event at 30 dg. Salivary cortisol pattern surrounding social mixing was used to select 6 stress resilient (SR) and 6 stress vulnerable (SV) focal females. SR females were those with an increase of cortisol at mixing but return to pre-mixing concentrations, and SV females were those with persistently elevated cortisol across all timepoints. Within 24 h of farrowing, one gilt piglet and one boar piglet of average size from each focal litter were humanely euthanized for terminal tissue collection (n=24 total). Total RNA was extracted from hypothalamic, hippocampal, and adrenal tissue and sequencing performed in 2x150 bp format using an Element Biosciences AVITI instrument. An average of 83 M reads were generated per sample. Reads were aligned to the Sus scrofa 11.1 reference genome using HISAT2, and gene counts obtained using HTSeq. Differential expression analysis was performed using DESeq2 to assess transcript abundance in the SR offspring relative to SV offspring. The model included fixed effects of stress group, piglet sex, the interaction between stress group and piglet sex, sire, and farrowing group. Differentially expressed genes (DEGs) were defined as those with a Benjamini-Hochberg adjusted P-value 2 Fold Change (log2FC). A total of 20 hypothalamic, 4 hippocampal, and 922 adrenal DEGs were detected. Gene set enrichment analysis was performed on the adrenal DEGs using the g:GOSt function of g:Profiler. Among adrenal DEGs, those with higher expression in SR offspring were enriched for pathways related to reproductive processes, peptide hormone metabolism, insulin secretion, and glucagon receptor binding (FDR < 0.1). Adrenal DEGs with lower expression in SR offspring were enriched for pathways related to epigenetic regulation of gene expression, intrauterine growth retardation, growth delay, stress-induced signaling cascades, and telomere maintenance (FDR < 0.05). These data suggest that maternal resilience to social stress has a minimal impact on hypothalamic or hippocampal gene expression profiles in neonatal pigs, but significantly alters the adrenal transcriptome with potential impacts on metabolism, growth, and reproduction.

Keywords: 2026

How to Cite:

Luttman, A., Raney, N. & Ernst, C., (2026) “Neonatal piglets exhibit differential gene expression in brain and adrenal tissue associated with maternal resilience to social stress”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2285022. doi: https://doi.org/10.31274/wcgalp.23626

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