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| Author(s): |
Laura Cristina Multini
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Saúde Pública (FSP/CIR) |
| Defense date: | 2020-03-26 |
| Examining board members: |
Mauro Toledo Marrelli;
Tamara Nunes de Lima Camara;
Flavia Virginio Fonseca;
Karin Kirchgatter
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| Advisor: | Mauro Toledo Marrelli |
| Abstract | |
Anthropogenic changes in the environment can be a powerfull aspect in the evolution of the species. Fragmentation of natural areas due to human interference has been associated with the decrease of species richness and increase in the abundance of species that are adapted to these environments. The Brazilian Atlantic Forest has been undergoing an intense process of fragmentation and deforestation due to anthropogenic alterations in the environment. This biome is an important hotspot of malaria transmission, in which the main vector of simian and human malaria is the mosquito Anopheles cruzii. We hypothesized that anthropogenic alterations in the environment are an important driver for the phenotypic and genetic structure and diversity of An. cruzii. We tested five different hypotheses using both a cross-sectional and longitudinal design to assess the sympatric structure and microevolution process driving An. cruzii populations. We used both wing geometry and SNPs to assess the microgeographical genetic structure of An. cruzii populations in a malaria hypo-endemic area in the city of São Paulo, Brazil. In this region, anthropogenic modifications in the environment suppress the Atlantic Forest into fragments, resulting in mosquitoes An. cruzii, Plasmodium and humans living in simpatry. Our results show a slight but significant phenotypic variation in all three populations over the study period. Time was a more powerful driver for wing variation than geographic distance. Temporal wing-shape variation appears to be positively associated with urbanization, suggesting that anthropogenic changes in the environment may be a strong driver for wing-shape variation in An. cruzii. After filtering and removal of outlier loci, 1,235 SNPs were considered independent and neutral, and therefore, suitable to perform the analyses. The results showed an overall weak genetic structure among populations with a significant sympatric structure between ground and tree canopies populations from the urban area, with the population from ground level showing higher genetic diversity. Our findings indicate that anthropogenic modifications leading to habitat fragmentation could be driving the acrodendrophily of An. cruzii and maintaining genetic diversity and structure in populations from ground level. (AU) | |
| FAPESP's process: | 15/23386-7 - Microevolution studies in Anopheles cruzii (Diptera: Culicidae), using wing geometric morphometric and microsatellite loci |
| Grantee: | Laura Cristina Multini |
| Support Opportunities: | Scholarships in Brazil - Doctorate |