Characterization of Anopheles darlingi (Diptera: Culicidae) populations from Brazil by external morphological structure of eggs, wings and gene sequences

Author(s)

Maysa Tiemi Motoki

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Saúde Pública (FSP/CIR)
• Defense date: 2012-02-27

Examining board members

Maria Anice Mureb Sallum; Mauro Toledo Marrelli; Ricardo Lourenço de Oliveira; Alexandre Afranio Peixoto; Lincoln Suesdek Rocha

• Advisor: Maria Anice Mureb Sallum

Abstract

Introduction Malaria is a major human disease that primarily affects poor persons in tropical and subtropical regions where environmental conditions are favorable to the proliferation of the etiological agent as well as vector mosquitoes. In Brazil, Anopheles darlingi is considered a primary vector of human plasmodia and has been the target of control campaigns because of its medical importance. However, the occurrence of microevolution in An. darlingi was not considered and, consequently, the possibility of different populations exhibit distinct biological characteristics. Objective Verify the presence of morphological and genetic variability in Brazilian Anopheles darlingi populations. Methods Twenty six attributes of external egg morphology were analyzed and compared in nine populations. Similarly, the geometric morphometry of wing shape was evaluated in ten An. darlingi localities. In addition, the mitochondrial gene cytochrome oxidase subunit I (COI) was employed to analyze the population structure of An. darlingi. Results and Conclusion - Although, egg attributes showed variation, only samples from Tocantins and Pará were differentiated from other populations. Variation in external egg structure is arguably adaptive in light of environmental factors such as temperature, humidity and food availability for females. Comparisons of wing geometric morphometry indicated that there is greater similarity between Coastal (Espírito Santo and Rio de Janeiro states) and Inner (São Paulo and Paraná states) populations of the Atlantic Forest, and differentiation of those from (Goiás and Tocantins states) and regions both north (Amazonas and Amapá states) and south (Pará and Mato Grosso states) of the Amazon Region. Cytochrome oxidase I analyses indicated differentiation between coastal Atlantic Forest populations (Espírito Santo and Rio de Janeiro states) and those from the cerrado, the Amazon and the interior Atlantic Forest. The pattern of COI haplotype diversity, neutrality tests and distribution of pairwise differences suggest a recent demographic expansion. Geographical distance, ecoregions and potentially environmental constraints may limit the species´ dispersal and influence the population structure of An. darlingi (AU)

• FAPESP's process: 07/07573-5 - Characterization of Brazilian population of Anopheles darlingi (Diptera: Culicidae) by morphological characteristics of eggs and wings and gene sequences
• Grantee: Maysa Tiemi Motoki
• Support Opportunities: Scholarships in Brazil - Doctorate