Featured Research

from universities, journals, and other organizations

Malarial mosquitoes are evolving into new species, say researchers

Date:
October 21, 2010
Source:
Imperial College London
Summary:
Two strains of the type of mosquito responsible for the majority of malaria transmission in Africa have evolved such substantial genetic differences that they are becoming different species, according to researchers behind two new studies published today in the journal Science. This means that efforts to control mosquito populations may be effective against one strain of mosquito but not the other.

Two strains of the Anopheles gambiae mosquito: the top one is from the M strain, and the bottom one is from the S strain.
Credit: Photo by James Gathany/CDC, via VectorBase -- http://agambiae.vectorbase.org/

Two strains of the type of mosquito responsible for the majority of malaria transmission in Africa have evolved such substantial genetic differences that they are becoming different species, according to researchers behind two new studies published in the journal Science.

Related Articles


Over 200 million people globally are infected with malaria, according to the World Health Organisation, and the majority of these people are in Africa. Malaria kills one child every 30 seconds.

The international research effort, co-led by scientists from Imperial College London, looks at two strains of the Anopheles gambiae mosquito, the type of mosquito primarily responsible for transmitting malaria in sub-Saharan Africa. These strains, known as M and S, are physically identical. However, the new research shows that their genetic differences are such that they appear to be becoming different species, so efforts to control mosquito populations may be effective against one strain of mosquito but not the other.

The scientists argue that when researchers are developing new ways of controlling malarial mosquitoes, for example by creating new insecticides or trying to interfere with their ability to reproduce, they need to make sure that they are effective in both strains.

The authors also suggest that mosquitoes are evolving more quickly than previously thought, meaning that researchers need to continue to monitor the genetic makeup of different strains of mosquitoes very closely, in order to watch for changes that might enable the mosquitoes to evade control measures in the future.

Professor George Christophides, one of the lead researchers behind the work from the Division of Cell and Molecular Biology at Imperial College London, said: "Malaria is a deadly disease that affects millions of people across the world and amongst children in Africa, it causes one in every five deaths. We know that the best way to reduce the number of people who contract malaria is to control the mosquitoes that carry the disease. Our studies help us to understand the makeup of the mosquitoes that transmit malaria, so that we can find new ways of preventing them from infecting people."

Dr Mara Lawniczak, another lead researcher from the Division of Cell and Molecular Biology at Imperial College London, added: "From our new studies, we can see that mosquitoes are evolving more quickly than we thought and that unfortunately, strategies that might work against one strain of mosquito might not be effective against another. It's important to identify and monitor these hidden genetic changes in mosquitoes if we are to succeed in bringing malaria under control by targeting mosquitoes."

The researchers reached their conclusions after carrying out the most detailed analysis so far of the genomes of the M and S strains of Anopheles gambiae mosquito, over two studies. The first study, which sequenced the genomes of both strains, revealed that M and S are genetically very different and that these genetic differences are scattered around the entire genome. Previous studies had only detected a few 'hot spots' of divergence between the genomes of the two strains. The work suggested that many of the genetic regions that differ between the M and S genomes are likely to affect mosquito development, feeding behaviour, and reproduction.

In the second study, the researchers looked at many individual mosquitoes from the M and S strains, as well as a strain called Bamako, and compared 400,000 different points in their genomes where genetic variations had been identified, to analyse how these mosquitoes are evolving. This showed that the strains appear to be evolving differently, probably in response to factors in their specific environments -- for example, different larval habitats or different pathogens and predators. This study was the first to carry out such detailed genetic analysis of an invertebrate, using a high density genotyping array.

As a next step in their research, the Imperial researchers are now carrying out genome-wide association studies of mosquitoes, using the specially designed genotyping chip that they designed for their second study, to explore which variations in mosquito genes affect their propensity to become infected with malaria and other pathogens.

Both of the studies just published were collaborations between researchers at Imperial and international colleagues, involving researchers from institutions including the University of Notre Dame, the J. C. Venter Institute, Washington University and the Broad Institute. Funding for the projects was provided by the National Human Genome Research Institute, the National Institutes of Health, the BBSRC, and the Burroughs Wellcome Fund.


Story Source:

The above story is based on materials provided by Imperial College London. Note: Materials may be edited for content and length.


Journal References:

  1. M. K. N. Lawniczak, S. J. Emrich, A. K. Holloway, A. P. Regier, M. Olson, B. White, S. Redmond, L. Fulton, E. Appelbaum, J. Godfrey, C. Farmer, A. Chinwalla, S.-P. Yang, P. Minx, J. Nelson, K. Kyung, B. P. Walenz, E. Garcia-Hernandez, M. Aguiar, L. D. Viswanathan, Y.-H. Rogers, R. L. Strausberg, C. A. Saski, D. Lawson, F. H. Collins, F. C. Kafatos, G. K. Christophides, S. W. Clifton, E. F. Kirkness, and N. J. Besansky. Widespread Divergence Between Incipient Anopheles gambiae Species Revealed by Whole Genome Sequences. Science, 2010; 330 (6003): 512-514 DOI: 10.1126/science.1195755
  2. D. E. Neafsey, M. K. N. Lawniczak, D. J. Park, S. N. Redmond, M. B. Coulibaly, S. F. Traorι, N. Sagnon, C. Costantini, C. Johnson, R. C. Wiegand, F. H. Collins, E. S. Lander, D. F. Wirth, F. C. Kafatos, N. J. Besansky, G. K. Christophides, and M. A. T. Muskavitch. SNP Genotyping Defines Complex Gene-Flow Boundaries Among African Malaria Vector Mosquitoes. Science, 2010; 330 (6003): 514-517 DOI: 10.1126/science.1193036

Cite This Page:

Imperial College London. "Malarial mosquitoes are evolving into new species, say researchers." ScienceDaily. ScienceDaily, 21 October 2010. <www.sciencedaily.com/releases/2010/10/101020151324.htm>.
Imperial College London. (2010, October 21). Malarial mosquitoes are evolving into new species, say researchers. ScienceDaily. Retrieved February 27, 2015 from www.sciencedaily.com/releases/2010/10/101020151324.htm
Imperial College London. "Malarial mosquitoes are evolving into new species, say researchers." ScienceDaily. www.sciencedaily.com/releases/2010/10/101020151324.htm (accessed February 27, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, February 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Could a $34 Smartphone Device Improve HIV Diagnosis in Africa?

Could a $34 Smartphone Device Improve HIV Diagnosis in Africa?

Reuters - Innovations Video Online (Feb. 27, 2015) — A dongle that plugs into a Smartphone mimics a lab-based blood test for HIV and syphilis and can detect the diseases in 15 minutes, say researchers. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Doctor Says Head Transplants Possible Within Two Years

Doctor Says Head Transplants Possible Within Two Years

Buzz60 (Feb. 27, 2015) — An Italian doctor is saying he could stick someone&apos;s head onto someone else&apos;s body. Patrick Jones (@Patrick_E_Jones) reports. Video provided by Buzz60
Powered by NewsLook.com
How Your Dentist Could Help Screen You For Diabetes

How Your Dentist Could Help Screen You For Diabetes

Newsy (Feb. 27, 2015) — A new study from researchers at New York University suggests dentists could soon use blood samples taken from patients&apos; mouths to test for diabetes. Video provided by Newsy
Powered by NewsLook.com
The Best Tips to Makeover Your Health

The Best Tips to Makeover Your Health

Buzz60 (Feb. 27, 2015) — If you&apos;re looking to boost your health this season, there are a few quick and easy steps to prompt you for success. Krystin Goodwin (@Krystingoodwin) has the best tips to give your health a makeover this spring! Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins