Evaluation of the effect of stresses due to weaning and immune activation on pigs

Weaning is a stressor that can have significant impacts on health and physiology of the offspring. The effect of this stressor may be modulated by the exposure to other stressors during gestation such as the inflammatory signals of the mother in response to infection. The goal of this study is to determine the combined effects of weaning stress and immune stress during gestation on gene expression in the amygdala, a brain region critical for decision-making and aggression. A RNA-seq study of the amygdala of female and male pigs was undertaken. Within sex group, half of the pigs were weaned at 21 d of age and the rest remain with the gilts and were nursed. Also, half of the pigs in each group were raised from gilts exposed to a viral infection and half were raised by gilts that served as control. Overall design: One treatment factor studied was weaning (levels Weaned or Nursed). Another treatment factor studied was Porcine Reproductive and Respiratory (P) viral infection or saline control (C). The remaining factor was sex (Female and Male). Altogether 48 individual amygdala samples were obtained 24 hours later and analyzed using the TruSeq Stranded mRNAseq Sample Prep kit' (Illumina Inc, San Diego, CA, USA) to prepare RNAseq libraries. The libraries were sequenced on a NovaSeq 6000. Pair-ended reads of length 150bp were sequenced.