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Title: Distribution of mercury‐cycling genes in the Arctic and equatorial Pacific Oceans and their relationship to mercury speciation
Abstract

Humans are exposed to potentially harmful amounts of the neurotoxin monomethylmercury (MMHg) through consumption of marine fish and mammals. However, the pathways of MMHg production and bioaccumulation in the ocean remain elusive. In anaerobic environments, inorganic mercury (Hg) can be methylated to MMHg through an enzymatic pathway involving thehgcABgene cluster. Recently,hgcA‐like genes have been discovered in oxygenated marine water, suggesting thehgcABmethylation pathway, or a close analog, may also be relevant in the ocean. Using polymerase chain reaction amplification and shotgun metagenomics, we searched for but did not find thehgcABgene cluster in Arctic Ocean seawater. However, we detected Hg‐cycling genes from themeroperon (including organomercury lyase,merB), andhgcA‐like paralogs (i.e.,cdhD) in Arctic Ocean metagenomes. Our analysis of Hg biogeochemistry and marine microbial genomics suggests that various microorganisms and metabolisms, and not just thehgcABpathway, are important for Hg methylation in the ocean.

 
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NSF-PAR ID:
10457657
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Limnology and Oceanography
Volume:
65
Issue:
S1
ISSN:
0024-3590
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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