Mercury is altering gene expression

Typography

The mercury found at very low concentrations in water is concentrated along the entire food chain, from algae via zooplankton to small fish and on to the largest fish — the ones we eat. Mercury causes severe and irreversible neurological disorders in people who have consumed highly contaminated fish. Whereas we know about the element’s extreme toxicity, what happens further down the food chain, all the way down to those microalgae that are the first level and the gateway for mercury? By employing molecular biology tools, a team of researchers from the University of Geneva (UNIGE), Switzerland, has addressed this question for the first time. The scientists measured the way mercury affects the gene expression of algae, even when its concentration in water is very low, comparable to European environmental protection standards. Find out more about the UNIGE research in Scientific Reports.

The mercury found at very low concentrations in water is concentrated along the entire food chain, from algae via zooplankton to small fish and on to the largest fish — the ones we eat. Mercury causes severe and irreversible neurological disorders in people who have consumed highly contaminated fish. Whereas we know about the element’s extreme toxicity, what happens further down the food chain, all the way down to those microalgae that are the first level and the gateway for mercury? By employing molecular biology tools, a team of researchers from the University of Geneva (UNIGE), Switzerland, has addressed this question for the first time. The scientists measured the way mercury affects the gene expression of algae, even when its concentration in water is very low, comparable to European environmental protection standards. Find out more about the UNIGE research in Scientific Reports.

The UNIGE research team is led by Vera Slaveykova, professor of environmental biogeochemistry and ecotoxicology in the Department F.A. Forel for environmental and aquatic sciences, and vice-president of the School of Earth and environmental sciences, Faculty of Sciences of the UNIGE. The scientists selected a green microalga measuring barely six microns by ten, known as Chlamydomonas reinhardtii. The alga was chosen not because of its colour or the two flagella it uses to swim but because, of all the primary producers in the aquatic environment at the the lowest level of the food chain of the food chain, it is the one whose genome has been fully sequenced. The availability of this genomic information made it possible to compare gene expression of algae exposed to different concentrations of mercury and to determine the associated effects.

Continue reading at University of Geneva

Image: Green microalga Chlamydomonas reinhardtii, a model system for molecular biology and environmental studies.

Credit: Dartmouth College Electron Microscope Facility, Louisa Howard