Earthworms are proving to be great detectives when it comes to identifying what pollutants are present in our soils. They are helping scientists to build up a detailed picture of how toxic chemicals and metals in soils interact with living organisms, by demonstrating the effects these toxins have on their genes.
In new findings released today, a research team including Dr David Spurgeon and Dr Claus Svendsen from the Centre for Ecology & Hydrology and scientists from Cardiff and Edinburgh Universities and Imperial College London used a systems toxicology approach to understand the impact of four contaminants on earthworms (Lumbricus rubellus). Their findings are published in two complementary research papers in BioMed Central’s open access journals BMC Biology and BMC Genomics.
Using a new 8,000-element gene microarray (an analysis system that allows the measurement of thousands of genes using a single sample) the researchers tested the effects of copper, cadmium, the poly-aromatic hydrocarbon fluoroanthene, and the agrochemical atrazine.
The tests revealed subtle changes, induced by the toxins, in the worms’ gene expression patterns. The effects of copper exposure, in particular, identified genetic and metabolic changes as well as massive deterioration in the worms’ physical health.
Dr Peter Kille from Cardiff University led the research team. He said: ‘The research helps us to understand how, over millions of years, the earthworm has evolved adaptive mechanisms for dealing with soil pollution through genetically programmed responses. It also provides important clues to how humans will react or adapt to chemical exposure, as we share some common gene pathways with earthworms.’
This multidisciplinary research combined the systems toxicology approach with technologies usually used in isolation. The result is a powerful tool for understanding how ecologically important organisms like the earthworm respond to contaminants and also opens up the possibility of new, more effective, soil monitoring and bioremediation strategies.
The research was funded by the Natural Environment Research Council through its Environmental Genomics thematic programme.
The research referred to above is published in the following two scientific papers:
1. Systems toxicology approach identifies coordinated metabolic responses to copper in a terrestrial non-model invertebrate, the earthworm Lumbricus rubellus is published in BMC Biology.
Authors: Drs Jacob G. Bundy Jasmin K. Sidhu and Faisal Rana - Imperial College London, Drs David J. Spurgeon and Claus Svendsen - Centre for Ecology & Hydrology, Dr Stephen Sturzenbaum, University of Cardiff (now at Kings College London) and Drs Jodie F. Wren, A. John Morgan and Peter Kille - University of Cardiff.
2. Transcriptome profiling of developmental and xenobiotic responses in a keystone soil animal, the oligochaete annelid Lumbricus rubellus is published in BMC Genomics.
Authors: Authors: Dr Anne Hedley and Professor M. L. Blaxter – University of Edinburgh, Drs Matias J. Jonker, Peter K. Hankard, Linsey J. Lister, Claus Svendsen and David J. Spurgeon - Centre for Ecology & Hydrology, Dr Stephen Sturzenbaum, University of Cardiff (now at Kings College London) and Drs Jodie F. Wren, Jennifer Owen, A. John Morgan and Peter Kille - University of Cardiff.
The papers can be accessed through BioMed Central here (external site – open access)
More information about the research project can be found here (external site)