DNA can predict which Chernobyl species are at risk of radioactive damage

DNA could be the key to predict which species In Chernobyl are likely to be most severely damaged by radioactive contamination.

London: DNA could be the key to predict which species In Chernobyl are likely to be most severely damaged by radioactive contamination, according to scientists.

The secret to a species`` vulnerability, they say, lies in its DNA.

The discovery could reveal which species are most likely to decline or even become extinct in response to other types of environmental stress.

Professor Tim Mousseau from the University of South Carolina, US, and Dr Anders Moller from the National Centre for Scientific Research in Paris, France, led the study.

The two scientists have been working in Chernobyl for more than a decade, gathering data about the populations of insects, birds and mammals in "zone of alienation" surrounding the desolate nuclear power station.

For this study, they used existing databases to examine in detail the DNA patterns of each of the species they had studied in Chernobyl.

With every generation of a species`` lineage, the pattern of its DNA changes ever so slightly, as a result of the natural balance between mutations and the individual``s ability to repair damaged DNA. This is how species evolve.

The rate of this change - as each piece of the DNA code is replaced by another - is called the substituion rate.

"This information is available in large database. So you can get the DNA sequences [of each species] and examine the changes that have occurred among a species over time," the BBC quoted Mousseau as explaining.

Migrating birds have been particularly badly affected by the contamination.

"What we have discovered is that when we look at the species in Chernobyl, we can predict, based on their substitution rates, which ones are most vulnerable to contaminants,” he added.

Professor Mousseau said that the Chernobyl setting offered a "unique opportunity to look at a natural experiment in progress - [to see] what happens to species when they have this kind of environmental perturbation".

The results of this study could shed light on which species are most vulnerable to other kinds of environmental contamination.

Brightly coloured birds and birds that have a long distance migration were some of the organisms most likely to be affected by contaminants.

"One explanation may be that these species have, for whatever reason, less capable DNA repair mechanisms," said Professor Mousseau.

The study has been published in the Journal of Evolutionary Biology.