Research over the past several years has demonstrated the adverse effects of industrial pollutants in water and sediment on the health of fish in the lower Duwamish River. The Duwamish flows through an industrialized section of south Seattle, Wash., and in 2001 a section of the lower river was added to the Environmental Protection Agency’s Superfund list because of contaminants including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), mercury and other metals, and phthalates. In previous research on Duwamish fish, PNRI used an infrared spectroscopy method to document DNA damage in the gills of English sole.
In a new joint paper, the researchers report on several biomarkers, including pollution-induced P450 enzyme changes, and on infrared spectral analysis of DNA and measurements of specific modifications to DNA from fish gills and livers using liquid and gas chromatography combined with mass spectrometry (LC/MS,GC/MS). Precision chemical analysis techniques at NIST allowed the researchers to identify and measure damage to adenine and guanine, specific chemical components or bases of DNA, at extraordinarily low levels--five lesions out of a 100 million bases in one case. The results correlated well with earlier research and revealed similar damage to liver DNA (more likely tied to the fish’s food) and gill DNA (more probably reflecting pollutants in water).
The results suggest that these DNA lesions, and others like them, can be used as very sensitive biomarkers to provide a direct measure of the impact of contaminants on fish populations. Moreover, since natural DNA repair processes may gradually reverse the damage in the absence of further insults, these biomarkers also might be used to help assess the efficacy of pollution remediation efforts. The work was funded in part by the National Institute of Environmental Health Sciences (NIH).
Michael Baum | EurekAlert!
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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