Malaria remains the most important vector-borne disease globally, affecting 300-500 million persons annually. Of the 15 million cases reported from Latin America, more than 50% are from Brazil. In anopheline mosquitoes responsible for malaria transmission, little is known about gene flow, which can provide valuable information about local patterns of dispersal and malaria transmission. Using molecular techniques, this project proposes to elucidate gene flow and population genetics within species of the Anopheles albitarsis complex and An darlingi in Amazonian Brazil. Anopheles darlingi is the most efficient malaria vector in Latin America while species in the An. albitarsis complex have been implicated as important local vectors in Brazil. Both species are in the Argyritarsis Section in the subgenus Nyssorhynchus. Adult mosquitoes will be collected bi-monthly in two adjacent endemic malaria sites in Amapa State in Amazonian Brazil. Mitochondrial DNA haplotype profiles will be analyzed for temporal and microgeographic changes. The effective migration rates (Nem) will be computed using 4 methods. Molecular identification of cryptic species will be coupled with parasite detection by ELISA and dissection. An attempt will be made to link specific haplotypes to infectivity and to evaluate the significance of this for malaria transmission. A PCR-based probe for more rapidly and efficiently identifying vector species will be developed and tested. Mosquitoes will be collected along a transect to examine regional gene flow within species based on biological and ecological differences of Art albitarsis and An. darlingi. A phylogenetic hypothesis for the evolutionary relationships among species in the Argyritarsis Section will be constructed using molecular and morphological data sets.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29AI040116-02
Application #
2517357
Study Section
Special Emphasis Panel (ZRG5-TMP (01))
Project Start
1996-09-30
Project End
2001-08-31
Budget Start
1997-09-01
Budget End
1998-08-31
Support Year
2
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of Vermont & St Agric College
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
066811191
City
Burlington
State
VT
Country
United States
Zip Code
05405
Scarpassa, Vera Margarete; Conn, Jan E (2007) Population genetic structure of the major malaria vector Anopheles darlingi (Diptera: Culicidae) from the Brazilian Amazon, using microsatellite markers. Mem Inst Oswaldo Cruz 102:319-27
Conn, Jan E; Vineis, Joseph H; Bollback, Jonathan P et al. (2006) Population structure of the malaria vector Anopheles darlingi in a malaria-endemic region of eastern Amazonian Brazil. Am J Trop Med Hyg 74:798-806
Armbruster, Peter; Damsky Jr, William E; Giordano, Rosanna et al. (2003) Infection of New- and Old-World Aedes albopictus (Diptera: Culicidae) by the intracellular parasite Wolbachia: implications for host mitochondrial DNA evolution. J Med Entomol 40:356-60
Onyabe, D Y; Vajime, C G; Nock, I H et al. (2003) The distribution of M and S molecular forms of Anopheles gambiae in Nigeria. Trans R Soc Trop Med Hyg 97:605-8
Povoa, Marinete M; Conn, Jan E; Schlichting, Carl D et al. (2003) Malaria vectors, epidemiology, and the re-emergence of Anopheles darlingi in Belem, Para, Brazil. J Med Entomol 40:379-86
Armbruster, Peter; Hutchinson, Robert A (2002) Pupal mass and wing length as indicators of fecundity in Aedes albopictus and Aedes geniculatus (Diptera: Culicidae). J Med Entomol 39:699-704
Fairley, T L; Povoa, M M; Conn, J E (2002) Evaluation of the Amazon River delta as a barrier to gene flow for the regional malaria vector, Anopheles aquasalis (Diptera: Culicidae) in northeastern Brazil. J Med Entomol 39:861-9
Conn, Jan E; Wilkerson, Richard C; Segura, M Nazare O et al. (2002) Emergence of a new neotropical malaria vector facilitated by human migration and changes in land use. Am J Trop Med Hyg 66:18-22
Onyabe, D Y; Conn, J E (2001) The distribution of two major malaria vectors, Anopheles gambiae and Anopheles arabiensis, in Nigeria. Mem Inst Oswaldo Cruz 96:1081-4
Onyabe, D Y; Conn, J E (2001) Genetic differentiation of the malaria vector Anopheles gambiae across Nigeria suggests that selection limits gene flow. Heredity 87:647-58

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