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ARS Home » Northeast Area » Orono, Maine » National Cold Water Marine Aquaculture Center » Research » Publications at this Location » Publication #336849

Research Project: Genetic Improvement Of Marine Fish and Shellfish

Location: National Cold Water Marine Aquaculture Center

Title: The genomic landscape of rapid, repeated evolutionary rescue from toxic pollution in wild fish

item REID, NOAH - Dominican University Of California
item Proestou, Dina
item CLARK, BRYAN - Environmental Protection Agency (EPA)
item WARREN, WESLEY - Washington University
item COLBOURNE, JOHN - University Of Birmingham
item SHAW, JOSEPH - Indiana University
item KARCHNER, SIBEL - Woods Hole Oceanographic Institute (WHOI)
item HAHN, MARK - Woods Hole Oceanographic Institute (WHOI)
item NACCI, DIANE - Environmental Protection Agency (EPA)
item OLEKSIAK, MARJORIE - University Of Miami
item CRAWFORD, DOUGLAS - University Of Miami
item WHITEHEAD, ANDREW - Dominican University Of California

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/7/2016
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Several populations of Atlantic killifish (Fundulus heteroclitus) in contaminated Atlantic coast estuaries have evolved resistance to the toxic effects of PCBs, dioxins, and PAHs. However, the genetic mechanisms of resistance and whether they are shared among populations is not known. We sequenced the whole genomes of 43-50 individual fish from each of four populations of resistant fish (New Bedford Harbor, MA; Bridgeport, CT; Newark, NJ; Elizabeth River, VA) and nearby sensitive populations and compared gene expression profiles in response to PCB exposure. The genomic and transcriptomic analyses identified the aryl hydrocarbon receptor (AHR) signaling pathway as a shared target of selection. AHR pathway genes under selection are both shared and population-specific. Distinct molecular variants contribute to AHR pathway modification among populations. This suggests evolutionary constraints on mechanisms of adaptation, but multiple possible molecular solutions. Selection also targeted genes of signaling pathways connected to the AHR pathway (suggesting compensatory adaptations) and other toxicity-mediating genes (indicating complex tolerance phenotypes in response to complex mixtures). The molecular changes suggest selection on standing genetic variation. The high genetic diversity of Atlantic killifish has likely enabled natural selection to propel their rapid adaptation to toxic chemicals introduced by humans over the past 75 years. (Supported by NSF and NIEHS/SRP.)