Adult Killifish Exposure to Crude Oil Perturbs Embryonic Gene Expression and Larval Morphology in First- and Second-Generation Offspring

Exposures to environmental
toxicants can have both immediate
and
long-term impacts, including those that persist into the next generation.
Using Gulf killifish (Fundulus grandis), we tested whether adult progenitor exposure to crude oil caused
perturbations to larval morphology and embryonic genome-wide gene
expression in their first- and second-generation descendants raised
in clean water. We also tracked responses of additional direct oil
exposure in F1 and F2 embryos. Exposure to oil in progenitor fish
caused an altered larval morphology, especially in F2 descendants.
Some perturbations observed in descendent fish were enhanced by additional
direct oil exposure in lineages with progenitors that had been exposed
to oil. Progenitor exposures altered embryonic gene expression in
F1 and F2 descendants, implicating impacts on neurological and cardiovascular
systems. Molecular responses to progenitor exposure were distinct
between F1 and F2 offspring, suggesting complex interactions between
mechanisms that contribute to the transgenerational transfer of information.
In contrast, molecular responses to additional direct oil exposure
during early life development were highly conserved between generations
and between progenitor exposure treatments. We conclude that exposure
to crude oil causes developmental perturbations that propagate for
at least two generations, and we present additional hypotheses about
underlying molecular mechanisms and emergent health consequences.