Mosquito borne diseases such as malaria and dengue cause suffering and death around the world. Malaria alone causes at least one million deaths annually, and is particularly devastating in children under the age of five. In addition to the human toll, these diseases consume vast economic resources in the very communities that can least afford it. Various approaches to controlling these diseases such as insecticides, vaccine development, and preventive medicine have had limited success. The insect vectors responsible for spread of these diseases are widespread, numerous and adapt rapidly.
Another possibility for reducing the spread of disease by these insect vectors is genetically modifying the mosquitoes. Scientists have introduced genes into mosquitoes that render them unable to carry the human pathogens they often harbor and transmit to people. However, releasing these genetically modified mosquitoes into wild populations would not change the rate of disease transmission. In order to reduce pathogen transmission, it is critical that the modified mosquitoes supplant the wild population. Population genetics tells us that this is unlikely to occur under normal conditions even if huge numbers of modified mosquitoes are released into the wild.
One way to promote the spread of anti-pathogen genes in a population is by linking them with selfish genetic elements. Selfish genetic elements are pieces of DNA that propagate much more rapidly in populations than other DNA. By linking the desired genes with these rapidly spreading selfish elements, researchers believe that entire populations of mosquitoes can be changed from vectors of deadly pathogens to merely annoying pests.
There are a number of naturally occurring selfish genetic elements. The most familiar of these are transposable elements, often called jumping genes, but more exotic examples include sex ratio distorters, and gamete killers. Each selfish element uses a sli
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| Contact: Kristin Jenkins kjenkins@nescent.org 919-668-4544 National Evolutionary Synthesis Center (NESCent) Source:Eurekalert |