Microevolution of Aedes aegypti from São Paulo City

Abstract

Aedes aegypti (Culicidae) is a vector of dengue virus, yellow fever and other arboviruses. Originally from Africa, it is present on all continents owing to the passive transport of their immature forms, especially of eggs, which are resistant to desiccation. The species exhibits anthropophilic and synanthropic habits, and represents a public health problem since it is directly involved with millions of annual cases of dengue in the world. As an example, the city of Sao Paulo registered more than 6,000 Dengue cases in 2010. Considering that Dengue vaccine is still under development, prevention is the population control of Ae. aegypti. Among the available strategies for mosquito control, the application of insecticides is jeopardized by the development of resistance through microevolution of these insects. Microevolutionary events are thus a central subject in biological research. Those events can be fast in Ae. aegypti and changes are often detected in allele frequencies of DNA microsatellite. Another biological marker, the wing shape, may be also used as indicator of evolution in Ae. aegypti, since it is determined by quantitative genetic heritage. Considering the epidemiologic relevance of this vector mosquito in São Paulo city and that the microevolution of this species is poorly known, we intend to detect and describe microevolutionary processes of Ae. aegypti in this city. To that purpose, four samples per year (trimonthly fashion) will be compared regarding the allelic variability of microsatellites. Wing geometric variations will also be comparatively analised, which will permit us to compare the power of this phenetic marker to accuse microevolution. Considering that the rapid evolution of Ae. aegypti has a direct influence on the efficiency of control methods, describing microevolutionary processes of these mosquitoes of medical interest can lead to the development of more effective strategies for vector population control. (AU)