Chromatin dynamics and gene expression response to heat ex-posure in field-conditioned versus laboratory-cultured Nema-tostella vectensis

Organisms’ survival
is associated with the ability to respond to natural or anthropogenic
environmental stressors. Frequently, these responses involve changes in gene
regulation and expression, consequently altering physiology, development, or
behavior. Here, we present modifications in response to heat exposure that
mimics extreme summertime field conditions of lab-cultured and
field-conditioned Nematostella vectensis. Using ATAC-seq and RNA-seq
data, we found field-conditioned animals had a more concentrated reaction to
short-term thermal stress, expressed as enrichment of the DNA repair mechanism
pathway. In contrast, lab animals had a more diffuse reaction that involved a
larger number of differentially expressed genes and enriched pathways,
including amino acid metabolism. Our results demonstrate that pre-conditioning
affects the ability to respond efficiently to heat exposure in terms of both
chromatin accessibility and gene expression and reinforces the importance of
experimentally addressing ecological questions in the field.