Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers at LSTM crack the genetic secret of mosquito resistance to DDT and ITNs

25.02.2014
Paper shows a single genetic mutation causes resistance to both

Researchers from LSTM have found that a single genetic mutation causes resistance to DDT and pyrethroids (an insecticide class used in mosquito nets). With the continuing rise of resistance the research, published in the journal Genome Biology, is key as scientists say that this knowledge could help improve malaria control strategies.

The researchers, led by Dr Charles Wondji, used a wide range of methods to narrow down how the resistance works, finding a single mutation in the GSTe2 gene, which makes insects break down DDT so it's no longer toxic. They have also shown that this gene makes insects resistant to pyrethroids raising the concern that GSTe2 gene could protect mosquitoes against the major insecticides used in public health.

Mosquitoes (Anopheles funestus) are vectors of malaria, and most strategies for combating the spread of the disease focus on control of mosquito populations using insecticides. The spread of resistance genes could hold back efforts to prevent the disease. The authors say that knowing how resistance works will help to develop tests, and stop these genes from spreading amongst mosquito populations.

Charles Wondji said: 'We found a population of mosquitoes fully resistant to DDT (no mortality when they were treated with DDT) but also to pyrethroids. So we wanted to elucidate the molecular basis of that resistance in the population and design a field applicable diagnostic assay for its monitoring.'

They took mosquitoes from Pahou in Benin, which were resistant to DDT and pyrethroids, and mosquitoes from a laboratory fully susceptible strain and did a genome wide comparison study. They identified the GSTe2 gene as being upregulated - producing a lot of protein - in Benin mosquitoes.

They found that a single mutation (L119F) changed a non-resistant version of the GSTe2 gene to a DDT resistant version. They designed a DNA-based diagnostic test for this type of resistance (metabolic resistance) and confirmed that this mutation was found in mosquitoes from other areas of the world with DDT resistance but was completely absent in regions without. X-ray crystallography of the protein coded by the gene illustrated exactly how the mutation conferred resistance, by opening up the 'active site' where DDT molecules bind to the protein, so more can be broken down. This means that the mosquito can survive by breaking down the poison into non-toxic substances.

They also introduced the gene into fruit flies (Drosophila melanogaster) and found they became resistant to DDT and pyrethroids compared to controls, confirming that just this single mutation is enough to make mosquitoes resistant to both DDT and permethrin.

Wondji says: 'For the first time, we have been able to identify a molecular marker for metabolic resistance (the type of resistance most likely to lead to control failure) in a mosquito population and to design a DNA-based diagnostic assay. Such tools will allow control programs to detect and track resistance at an early stage in the field, which is an essential requirement to successfully tackle the growing problem of insecticide resistance in vector control. This significant progress opens the door for us to do this with other forms of resistance as well and in other vector species.'

Notes to Editors

1. A single mutation in the GSTe2 gene allows tracking of metabolically-based insecticide resistance in a major malaria vector
Riveron J M, Yunta C, Ibrahim S S, Djouaka R, Irving H, Menze B D, Ismail H M, Hemingway J, Ranson H, Albert A and Wondji C S Genome Biology 2014, 15:R27

During embargo, article available here: https://www.dropbox.com/sh/15nai29eftd2wuu/o0ipj1bh42

After embargo, article available at journal website here: http://genomebiology.com/2014/15/2/R27

Please name the journal in any story you write. If you are writing for the web, please link to the article. All articles are available free of charge, according to BioMed Central's open access policy.

For further information, please contact:

Mrs Clare Bebb
Senior Media Officer
Liverpool School of Tropical Medicine
Office: +44 (0)151 705 3135
Mobile: +44 (0)7889535222
Email: c.bebb@liv.ac.uk

Liverpool School of Tropical Medicine (LSTM) has been engaged in the fight against infectious, debilitating and disabling diseases since 1898 and continues that tradition today with a research portfolio in excess of well over £200 million and a teaching programme attracting students from over 65 countries.

For further information, please visit: http://www.lstmliverpool.ac.uk

Clare Bebb | EurekAlert!

Further reports about: DDT ITNs LSTM Medicine insecticide insects mosquito pyrethroids resistance strategies vector

More articles from Life Sciences:

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>