Researchers show the importance of copy-number variants in the development of insecticide resistance in malaria mosquitoes

July 26, 2019

Researchers from LSTM, working alongside colleagues from the Wellcome Sanger Institute, Cambridge and the Big Data Institute, University of Oxford, have used whole genome sequencing to understand copy-number variants (CNVs) in malaria mosquitoes and their role in insecticide resistance.

Many diseases, such as malaria, Zika and Dengue, are transmitted by mosquitoes, making control of mosquito populations a cornerstone of efforts to tackle these diseases. This is usually achieved through the use of insecticides, traditionally to great effect. Dr Eric Lucas, first author on a paper published in the journal Genome Research, explained: "Cases of malaria have been greatly reduced in the last 20 years, primarily due to improved vector control. These efforts are however threatened by the evolution of resistance to insecticides in many medically-important mosquito species. To better understand and address insecticide resistance, we need to understand the genetic mutations that cause it, but only a few mutations have so far been discovered."

In order to better understand the evolution of resistance, LSTM along with collaborators at the University of Oxford and the Wellcome Sanger Institute, are sequencing the genomes of thousands of individuals of the main malaria mosquito, Anopheles gambiae, from across Sub-Saharan Africa as part of a project called the An. gambiae 1000 Genomes project (Ag1000G).

One type of mutation that could lead to increased insecticide resistance is the gain of extra copies of genes that help to break down the insecticide in the mosquito body, yet there has been little research into such copy-number variants (CNVs) in malaria mosquitoes. For this work, the team used the Ag1000G data to look for increases in copy-number in An. gambiae and found that CNVs were much more likely to occur in genes that play a role in insecticide resistance than in the rest of the genome. "These resistance-associated CNVs were found in nearly every population in our study," continued Dr Lucas, "and over 90% of mosquitoes had increases in copy-number in some populations. Overall, in the five genetic regions known to be associated with the detoxification of insecticides in An. gambiae, we found a total of 44 different CNVs. The repeated origins of increased copy-number in the same genes, suggest that this type of mutation is relatively frequent and could provide a means of rapid evolutionary response to insecticide for the mosquitoes."

Professor Martin Donnelly, Head LSTM's Department of Vector Biology, was Senior author on the paper. He said: "This research demonstrates the importance of increases in gene copy-number in the evolution of insecticide resistance and should spur on research into understanding the exact effect of each of the CNVs, and the insecticides against which they act. Once these effects are understood, testing the presence of these mutations and tracking their spread between populations will help us predict the insecticides against which a mosquito population may still be susceptible."
-end-
Whole-genome sequencing reveals high complexity of copy number variation at insecticide resistance loci in malaria mosquitoes

Eric R. Lucas, Alistair Miles, Nicholas J. Harding, Chris S. Clarkson, Mara K.N. Lawniczak, Dominic P. Kwiatkowski, David Weetman, Martin J. Donnelly, and The Anopheles gambiae 1000 Genomes Consortium

Genome Res. Published in Advance July 25, 2019, doi:10.1101/gr.245795.118

Liverpool School of Tropical Medicine

Related Science Articles from Brightsurf:

75 science societies urge the education department to base Title IX sexual harassment regulations on evidence and science
The American Educational Research Association (AERA) and the American Association for the Advancement of Science (AAAS) today led 75 scientific societies in submitting comments on the US Department of Education's proposed changes to Title IX regulations.

Science/Science Careers' survey ranks top biotech, biopharma, and pharma employers
The Science and Science Careers' 2018 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.

Science in the palm of your hand: How citizen science transforms passive learners
Citizen science projects can engage even children who previously were not interested in science.

Applied science may yield more translational research publications than basic science
While translational research can happen at any stage of the research process, a recent investigation of behavioral and social science research awards granted by the NIH between 2008 and 2014 revealed that applied science yielded a higher volume of translational research publications than basic science, according to a study published May 9, 2018 in the open-access journal PLOS ONE by Xueying Han from the Science and Technology Policy Institute, USA, and colleagues.

Prominent academics, including Salk's Thomas Albright, call for more science in forensic science
Six scientists who recently served on the National Commission on Forensic Science are calling on the scientific community at large to advocate for increased research and financial support of forensic science as well as the introduction of empirical testing requirements to ensure the validity of outcomes.

World Science Forum 2017 Jordan issues Science for Peace Declaration
On behalf of the coordinating organizations responsible for delivering the World Science Forum Jordan, the concluding Science for Peace Declaration issued at the Dead Sea represents a global call for action to science and society to build a future that promises greater equality, security and opportunity for all, and in which science plays an increasingly prominent role as an enabler of fair and sustainable development.

PETA science group promotes animal-free science at society of toxicology conference
The PETA International Science Consortium Ltd. is presenting two posters on animal-free methods for testing inhalation toxicity at the 56th annual Society of Toxicology (SOT) meeting March 12 to 16, 2017, in Baltimore, Maryland.

Citizen Science in the Digital Age: Rhetoric, Science and Public Engagement
James Wynn's timely investigation highlights scientific studies grounded in publicly gathered data and probes the rhetoric these studies employ.

Science/Science Careers' survey ranks top biotech, pharma, and biopharma employers
The Science and Science Careers' 2016 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.

Three natural science professors win TJ Park Science Fellowship
Professor Jung-Min Kee (Department of Chemistry, UNIST), Professor Kyudong Choi (Department of Mathematical Sciences, UNIST), and Professor Kwanpyo Kim (Department of Physics, UNIST) are the recipients of the Cheong-Am (TJ Park) Science Fellowship of the year 2016.

Read More: Science News and Science Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.