Malaria-transmitting mosquito evolving, NIH grantees find

A. gambiae is the most common vector of human malaria in sub-Saharan Africa, where rates of the disease are highest. The researchers compared the genomes of two emerging species, dubbed M and S. Given that M and S appear to be physically indistinguishable and interbreed often, they were unexpectedly different at the DNA level.

They also were found to behave differently and thrive in different habitats. For example, in the absence of predators, S mosquitoes outcompeted M mosquitoes, but the outcome was reversed when predators were present.

As these two emerging species of mosquito evolve to develop new traits and behaviors, changes in disease transmission could result, the authors say. This could complicate malaria control efforts, which currently are based on the mosquitoes' patterns of behavior and vulnerability to insecticides.

Future research will further investigate these emerging species, exploring how they compete with one another in various habitats and the molecular basis of their evolution. The results will be used to refine existing malaria interventions and inform the development of new disease prevention strategies.

The research was supported by the National Institute of Allergy and Infectious Diseases and the National Human Genome Research Institute, both components of NIH. More information about NIAID research on malaria and other vector-borne diseases is available at the NIAID Malaria (http://www.niaid.nih.gov/topics/malaria/Pages/default.aspx) and the NIAID Vector Biology Web portals (http://www.niaid.nih.gov/topics/vector/pages/default.aspx).

ARTICLES: DE Neafsey et al. Complex gene-flow boundaries among vector mosquito populations. Science. DOI: 10.1126/science.1193036 (2010).

MKN Lawniczak et al. Widespread divergence between incipient Anopheles gambiae species revealed by whole genome sequences. Science. DOI: 10.1126/science.1195755 (2010).

WHO: Adriana Costero-Saint Denis, Ph.D., of the Parasitology and International Programs Branch, NIAID, is available to comment on these articles.

CONTACT: To schedule interviews, please contact Nalini Padmanabhan, 301-402-1663, niaidnews@niaid.nih.gov.

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The National Institutes of Health (NIH)—The Nation's Medical Research Agency—includes 27 Institutes and Centers and is a component of the U. S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments and cures for both common and rare diseases.