Publication Date:
2022-05-25
Description:
Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Aquatic Toxicology (2018), doi:10.1016/j.aquatox.2018.10.007.
Description:
Atlantic killifish inhabiting polluted sites along the east coast of the U.S. have evolved
resistance to toxic effects of contaminants. One such contaminated site is the Acushnet River
estuary, near New Bedford Harbor (NBH), Massachusetts, which is characterized by very high
PCB concentrations in the sediments and in the tissues of resident killifish. Though killifish at
this site appear to be thriving, the metabolic costs of survival in a highly contaminated
environment are not well understood. In this study we compared the hepatic metabolite profiles
of resistant (NBH) and sensitive populations (Scorton Creek (SC), Sandwich, MA) using a
targeted metabolomics approach in which polar metabolites were extracted from adult fish livers
and quantified. Our results revealed differences in the levels of several metabolites between fish
from the two sites. The majority of these metabolites are associated with one-carbon
metabolism, an important pathway that supports multiple physiological processes including DNA
and protein methylation, nucleic acid biosynthesis and amino acid metabolism. We measured
the gene expression of DNA methylation (DNA methyltransferase 1, dnmt1) and demethylation
genes (Ten-Eleven Translocation (TET) genes) in the two populations, and observed lower
levels of dnmt1 and higher levels of TET gene expression in the NBH livers, suggesting possible
differences in DNA methylation profiles. Consistent with this, the two populations differed
significantly in the levels of 5-methylcytosine and 5-hydroxymethylcytosine nucleotides. Overall,
our results suggest that the unique hepatic metabolite signatures observed in NBH and SC
reflect the adaptive mechanisms for survival in their respective habitats.
Description:
This work was supported by the Joint Initiative Awards Fund from the Andrew W. Mellon
Foundation (NA and EBK) and National Institute of Environmental Health Sciences (NIEHS)
Superfund Research Program (P42ES007381) at Boston University. LG was supported by the
Postdoctoral Scholar Program at the Woods Hole Oceanographic Institution (with funding
provided by the Townsend Postdoctoral Scholarship Fund, and the John H. Steele Endowment
in support of Postdoctoral Research).
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
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