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| Author(s): |
Gisele Antoniazzi Cardoso
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2019-03-08 |
| Examining board members: |
Tatiana Teixeira Torres;
Rodrigo Cogni;
Ana Claudia Lessinger;
Diogo Meyer
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| Advisor: | Tatiana Teixeira Torres |
| Abstract | |
Closely related species of the Calliphoridae family have contrasting feeding habits, such as feeding on living tissues of a host (obligate parasitism) and feeding on decaying organ-ic matter (necro-saprophagy). The evolutionary origins of parasitism in Calliphoridae are still unknown. However, what makes this family ideal for the study of the evolution of feeding habits is the appearance of obligate parasitism in at least three independent oc-casions. In this study, we used methods to understand the evolution of parasitism, as well as the genes involved in in three different feeding habits. First, we inferred the ancestral habit of Calliphoridae. By using stochastic character mapping along the phylogeny of the family, the most likely ancestral habit was revealed as necro-saprophagy. Obligate para-sitism could have evolved later (with an independent evolution of the facultative parasit-ism). Two-choice essays with females allowed the precise classification of the species regarding their feeding habits. Essays with larvae showed that both necro-saprophagous and facultative parasites feed on decaying flesh and fresh meat. On the other hand, the obligate parasite, Co. hominivorax, showed an aversive behavior to decaying meat and able to develop only in fresh meat. These results led to the formulation of the hy-pothesis that parasitism arose from a shift in the attraction of the female attraction to new oviposition sites, followed by the specialization of the parasitic larvae. The search for the genes involved in the different feeding habits was performed through an analysis of differential gene expression using RNA-seq data generated for six califorids. Within a da-taset containing more than 1000 candidate genes, 230 genes potential candidate genes were found for future research. In addition, the general pattern observed indicated that both regulatory and coding regions have predominantly undergone the action of purifying selection (AU) | |
| FAPESP's process: | 14/01600-4 - Evolution of global gene expression in the family Calliphoridae |
| Grantee: | Gisele Antoniazzi Cardoso |
| Support Opportunities: | Scholarships in Brazil - Doctorate |