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Comparative populational analyses of Culex quinquefasciatus of two places of State of São Paulo.

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Maria Cristina Jurcovichi Peruzin
Total Authors: 1
Document type: Master's Dissertation
Press: São Paulo.
Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
Defense date:
Examining board members:
Lincoln Suesdek Rocha; Delsio Natal; Maria Anice Mureb Sallum
Advisor: Lincoln Suesdek Rocha

The mosquito Culex quinquefasciatus has medical importance due to its ability of vectoring arboviruses and filariases. Microevolution resulting in insecticide resistance is a remarkable limiting factor for populational control of this species. In the State of São Paulo there are two populations under different environmental conditions. One, near Rio Pinheiros (PIN), is subjected to pollution and pyrethroids applications and another, in Pariquera-Açu (PAR), lives in a semi-rural place in the absence of insecticides. The objective of this work was to investigate if these populations from different environments have geneticmorphological polymorphisms and if PIN population exhibits morphological variations during the time. Parameters used in the comparisons were wing geometric morphometrics, ribosomal DNA (rDNA), and polytene chromosomes. Karyotypic characterization was unsuccessful due to the poor definition of bands and interbands. Morphometrical analyses of 286 wings of PIN, collected in 2004 (PIN04) and 2007 (PIN07), and 150 wings of PARI, collected in 2008, demonstrate morphological variations. The two populations PIN04 and PIN07 revealed strong intrapopulational sexual dimorphism concerning shape and size, being the wings of females larger than those of males in both populations. The wing asymmetry is non-significant for size and tenuous for shape, being slightly more conspicuous in males and in PIN07. The specimens of PIN07 are larger and more bilaterally asymmetric than PARI, possibly due to higher food availability and to continuous exposition to high level of insecticide, respectively. Analysis of rDNA revealed restriction patterns equivalent for PIN07 and PARI populations. Thus, one may suppose that gene flow may have occurred until recently. This study showed that it is possible to occur size and shape variation of wings in Culicidae in time intervals as short as three years. The next step would be to evaluate in depth the relationship between geographical-temporal variation and some of possible causes like pollution and insecticides. (AU)

FAPESP's process: 06/05164-8 - Population characterization of Culex quinquefasciatus (Diptera:Culicidae): molecular, karyotypic and morphometric aspects
Grantee:Maria Cristina Jurcovichi Peruzin
Support Opportunities: Scholarships in Brazil - Master