Skip Navigation
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Internet Explorer is no longer a supported browser.

This website may not display properly with Internet Explorer. For the best experience, please use a more recent browser such as the latest versions of Google Chrome, Microsoft Edge, and/or Mozilla Firefox. Thank you.

Your Environment. Your Health.

Progress Reports: Boston University: Mechanisms and Impacts of PCB Resistant Fish

Superfund Research Program

Mechanisms and Impacts of PCB Resistant Fish

Project Leader: Mark E. Hahn (Woods Hole Oceanographic Institution)
Co-Investigators: Sibel I. Karchner (Woods Hole Oceanographic Institution), Neelakanteswar Aluru (Woods Hole Oceanographic Institution)
Grant Number: P42ES007381
Funding Period: 1995-2020
View this project in the NIH Research Portfolio Online Reporting Tools (RePORT)

Learn More About the Grantee

Visit the grantee's eNewsletter page Visit the grantee's eNewsletter page Visit the grantee's Twitter page View the grantee's Factsheet(377KB)

Progress Reports

Year:   2019  2018  2017  2016  2015  2014  2013  2012  2010  2009  2008  2007  2006  2005  2004  2003  2002  2001  2000  1999  1998  1997  1996  1995 

This year Mark Hahn, Ph.D., Sibel Karchner, Ph.D, Neel Aluru and colleagues provided new insights into the impact of long-term exposure to Superfund chemicals on natural populations, including the mechanisms involved in evolutionary adaptation of fish to extraordinarily high levels of PCBs in New Bedford Harbor. The researchers and their collaborators sequenced the genome of the Atlantic killifish (Fundulus heteroclitus) (Reid et al. 2017). Subsequently, they sequenced whole genomes of 43-50 individual fish from each of eight populations, including four populations of PCB-tolerant fish at Superfund sites. Genomic and transcriptomic analyses identified the aryl hydrocarbon receptor (AHR)-based signaling pathway as a key target of selection in all four tolerant populations (Reid et al. 2016). Four AHRs, AHR-interacting protein (AIP), and the AHR target gene CYP1A were shared targets of selection. However, distinct molecular variants contributed to adaptation in the different populations. There was also selection in signaling pathways connected to the AHR pathway, suggesting compensatory adaptations (Whitehead et al 2017). To better understand the function of AHRs and AIP, the researchers continued their efforts to use CRISPR-Cas9 to generate loss-of-function mutants in killifish and zebrafish. Additional studies characterized killifish genes involved in the response to hypoxia (low oxygen) (Townley et al. 2016) and examined the risk to terns feeding near the New Bedford Harbor Superfund site (Nacci et al. 2016). Overall, this research is helping to understand how natural populations of animals are affected by long-term exposure to toxic chemicals in the environment. The results illustrate the complex and extensive impact of exposure to mixtures of contaminants on the genetics of animal populations.

to Top