Featured Research

from universities, journals, and other organizations

Double Trouble With Insecticide-resistant Mosquitoes

Date:
April 9, 2008
Source:
BMC Evolutionary Biology
Summary:
Geneticists discover that insecticide resistance genes work together in mosquitoes, increasing their survival rate with important consequences for pest management. Mosquitoes harboring two insecticide-resistance genes have been found to survive unexpectedly well in an insecticide-free environment where carrying such genes would normally expected to be a burden. This results from the genes interacting with one another to the advantage of the host and to the detriment of pest management strategies affecting human health.

Mosquitoes harbouring two insecticide-resistance genes have been found to survive unexpectedly well in an insecticide-free environment where carrying such genes would normally expected to be a burden. This results from the genes interacting with one another to the advantage of the host Culex quinquefasciatus mosquitoes* and to the detriment of pest management strategies affecting human health.

The research team, led by Dr Vincent Corbel and colleagues from the Universitι Montpellier II, Genetics and Evolution of Infectious Diseases and The Research Institute for Development (IRD) in France compared the survival rates or evolutionary fitness of one strain of the mosquito that carried two resistance genes (ace-1R and KdrR) for two different insecticides to mosquitoes that only had one insecticide-resistance gene, a French research team discovered that the survival cost of having both genes was far lower than the cost of having just ace-1R.

"We know from evolutionary theory that mutations such as these are likely to be costly to their owners in environments where they have not been selected for" explained Dr Corbel. "We've found that in C. quinquefasciatus the cost of having the ace-1R mutation in the absence of insecticides is counterbalanced when the mosquito also has the KdrR mutation. Mosquitoes with both mutations will also be harder to control as they are resistant to two different types of insecticide."

The authors also found evidence that resistance alleles interact with one another in the presence of insecticides. For instance, synergism (that is, a more than an additive effect) in toxicity was observed when a pyrethroid insecticide and a carbamate insecticide were applied simultaneously to the strain sharing both mutations (the insecticide had a greater activity and more of the mosquitoes died), whereas antagonism (that is, a less than an additive effect) was noted with Culex mosquitoes carrying only ace-1R.

Resistance to so-called xenobiotics (antibiotics, insecticides and herbicides) is a problem affecting the control of organisms of medical or economic importance. In C. quinquefasciatus insecticide resistance mutations interacted to positively and negatively influence the mosquitoes' fitness. Costs were associated with both resistance genes in an insecticide-free environment. The KdrR form of the gene, or allele, however, compensated for the costs associated with the ace-1R allele, suggesting that mosquitoes with both genes in the wild could be more prevalent. Females with both alleles were more likely to mature than those with just the ace-1R mutation."

"It is important to identify genetic interactions such as this and how they influence the fitness of multiply resistant organisms in order to better structure management strategies" says Dr Corbel. "We have found in this case that resistance genes do interact and even compensate. We will have to be very careful in how we use insecticides in future as our results have major implications for pest and health management."

Journal reference: Costs and benefits of multiple resistance to insecticides for Culex quinquefasciatus mosquitoes. Claire Berticat, Julien Bonnet, Stephane Duchon, Philip Agnew, Mylene Weill and Vincent Corbel. BMC Evolutionary Biology (in press)

* Culex quinquefasciatus is an important carrier of West Nile virus in North America and bancraftian filariasis in Africa. Four strains of C. quinquefasciatus were used in this study: SLAB, SR, BC, BCSR. All share the same genetic background and cytoplasm and only differ in their genotype at ace-1R and KdrR ace-1R and KdrR confer resistance to carbamate and pyrethroid insecticides respectively


Story Source:

The above story is based on materials provided by BMC Evolutionary Biology. Note: Materials may be edited for content and length.


Cite This Page:

BMC Evolutionary Biology. "Double Trouble With Insecticide-resistant Mosquitoes." ScienceDaily. ScienceDaily, 9 April 2008. <www.sciencedaily.com/releases/2008/04/080407190606.htm>.
BMC Evolutionary Biology. (2008, April 9). Double Trouble With Insecticide-resistant Mosquitoes. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2008/04/080407190606.htm
BMC Evolutionary Biology. "Double Trouble With Insecticide-resistant Mosquitoes." ScienceDaily. www.sciencedaily.com/releases/2008/04/080407190606.htm (accessed July 30, 2014).

Share This




More Plants & Animals News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) — Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) — Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) — At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Raw: Otters Enjoy Water Slides at Japan Zoo

Raw: Otters Enjoy Water Slides at Japan Zoo

AP (July 30, 2014) — River otters were hitting the water slides to beat the summer heatwave on Wednesday at Ichikawa City's Zoological and Botanical Garden. (July 30) Video provided by AP
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:
from the past week

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