Meeting Abstract
Cross-generational effects of physical and pathogenic stress have been demonstrated in several insect groups. Prior studies in our lab have shown that, in the tobacco hornworm, Manduca sexta, maternal bacterial exposure increases variability in embryonic size and enhances larval bacterial clearance. The current project further characterizes the effects of maternal septic and aseptic injury on offspring, focusing on gene expression. M. sexta females were injected just before adult eclosion with sterile saline or live Serratia marcescens. Naïve controls received no treatment. After eclosion and mating with untreated males, embryos were examined for changes in gene expression. Hatching rates and frequencies were also measured. We observed changes in the expression of several immune-related genes in embryos of mothers treated with live bacteria, including prophenoloxidase-activating protease, in comparison to offspring of untreated or saline-treated mothers. In larvae, expression of the same immune-related genes increased in offspring of mothers from all treated groups relative to those from untreated mothers. Despite differences in gene expression, we observed no global alterations in histone acetylation. Future studies will elucidate whether methylation or histone acetylation of specific immune-related genes can help to explain changes in gene expression and immune response. Our results are consistent with maternal effects that enhance offspring immunity in stressful environments. Our thanks to support from NSF (REU Award 1460628), and from Northeastern University (Tier 1 and Undergraduate Research Awards).
