Transgenic anopheline mosquitoes impaired in transmission of a malaria parasite

Abstract

Malaria is estimated to cause 0.7 to 2.7 million deaths per year, but the actual figures could be substantially higher owing to under-reporting and difficulties in diagnosis. If no new control measures are developed, the malaria death toll is projected to double in the next 20 years. Efforts to control the disease are hampered by drug resistance in the Plasmodium parasites, insecticide resistance in mosquitoes, and the lack of an effective vaccine. Because mosquitoes are obligatory vectors for malaria transmission, the spread of malaria could be curtailed by rendering them incapable of transmitting parasites. Many of the tools required for the genetic manipulation of mosquito competence for malaria transmission have been developed. Foreign genes can now be introduced into the germ line of both culicine and anopheline mosquitoes, and these transgenes can be expressed in a tissue-specific manner. Here we report on the use of such tools to generate transgenic mosquitoes that express antiparasitic genes in their midgut epithelium, thus rendering them inefficient vectors for the disease. These findings have significant implications for the development of new strategies for malaria control.

Evolutionary history of a mosquito endosymbiont revealed through mitochondrial hitchhiking

“…For more than a decade a high-profile effort has been underway to genetically modify mosquitoes so that they no longer transmit pathogens (Beaty 2000). Transgenes that block pathogen transmission have been introduced into and expressed in mosquitoes (Ito et al 2002). However, no empirically demonstrated method to spread or 'drive' these engineered genetic traits into wild mosquito populations currently exists.…”

Site-specific selfish genes as tools for the control and genetic engineering of natural populations

“…Ribeiro & Kidwell 1994;Turelli & Hoffmann 1999;Beerntsen et al 2000;Ito et al 2002). As we have seen, engineered HEGs may be useful tools for such population genetic engineering.…”

Using underdominance to bi-stably transform local populations

“…Additionally, in certain situations, modified alleles are not expected to spread far beyond the initial release range nor be lost from the wild. This can be an important consideration for initial testing of refractory effector constructs (e.g., Ito et al (2002)) in field trials and for non-native invasive disease vectors that threaten susceptible species (e.g., Warner (1968)); local populations can be stably transformed to be refractory while a wildtype state is maintained in the vectors native range. Despite intensive work to this end in the 1970-80s, using radiation induced chromosomal rearrangements, this approach ultimately failed.…”