NEW YORK (GenomeWeb News) – Scottish scientists are using DNA barcoding in an effort to curb the spread of a virus-borne disease affecting animals such as cattle and sheep in the UK.
The team used barcoding to track tiny insects called biting midges that can carry and spread the bluetongue virus. By characterizing the midge populations at dozens of farms across Scotland, where bluetongue has not yet been found, the researchers say they may be able to predict bluetongue’s spread and come up with prevention or management strategies.
University of Aberdeen research assistant Jane DeGabriel is expected to present this work at the British Ecological Society’s annual meeting in London today.
“[W]e are using a genetic barcoding approach to identify the midges to species level using molecular methods,” DeGabriel said in a statement. “This is the first large-scale study of the distribution and abundance of Scottish midge species.”
Biting midges are small blood-sucking flies that are found in most parts of the world. For this study, DeGabriel and her colleagues focused on biting midges in the Culicoides genus, which can carry and transmit several human and animal pathogens including bluetongue.
Bluetongue afflicts ruminant animals such as sheep, cattle, and deer and is characterized by a high fever, inflammation, hemorrhaging of the mucous membranes, and — as the name suggests — a blue tongue and lips. The disease has been detected in the southern and southwestern US, as well as Australia, the Middle East, Asia, and Europe. The disease was first identified in the UK in 2007, but so far it has not been detected in Scotland.
In an effort to understand — and try to prevent — bluetongue’s spread into and within Scotland, DeGabriel and her team looked at distribution and species composition of Culicoides midges throughout the country. They sampled roughly a million midges caught with light traps on 37 Scottish farms and then used DNA barcoding to look at the distribution and abundance of four types of Culicoides obsoletus midges.
Using the information gleaned from this high-throughput genetic screen, they then created a “midge map” of the country, showing that species number, abundance, and mixtures all varied by location and with the season, potentially due to climate differences.
“These differences between and within sites appear to be due to differences in climatic conditions and habitat,” DeGabriel said. “Our findings provide vital information for assessing the risk of bluetongue being transmitted in Scotland and the effects of climate change on the spread of this and other animal diseases.”
In the future, the researchers are confident that such information will help them predict which midge species spread bluetongue and where they’re headed — information that could contribute to effective strategies for managing or halting the virus’ spread.
“Our results will help scientists and policy makers develop risk mitigation and management strategies for bluetongue and other animal diseases,” DeGabriel said.