Evolutionary history of Drosophila serido (\cluster\ Drosophila buzzatii)

Author(s)

Taís Carmona Lavagnini Pizzo

• Document type: Doctoral Thesis
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (PCARP/BC)
• Defense date: 2015-02-27

Examining board members

Maura Helena Manfrin; Fernando de Faria Franco; Iderval da Silva Júnior Sobrinho; Fábio de Melo Sene; Fernanda de Pinho Werneck

• Advisor: Maura Helena Manfrin

Abstract

Drosophila buzzatii cluster comprises seven species endemic of South America and that present a mandatory ecological association with cacti. Among these species, Drosophila serido has a wide geographical range, in Caatinga and along Atlantic coast, and is considered as a polytypic species, divided in two groups: northeast and coast populations. The purpose of this study was understand the process that shaped the current distribution of D. serido populations through genetic analysis using sequences of nuclear genes period and kl-5, X- and Y-linked, respectively, autosomal genes GstD1 e E5, and mitochondrial gene COI. The genetic homogeneity among Northeast populations and the north-south division among coast Atlantic populations were observed for all markers. Three patterns related to population structure in coast Atlantic were seen for the different markers. Hypothesis that Diamantina Plateau was the dispersion center for the species were confirmed at this study, although, TMRCA estimated for Santa Catarina populations suggested that these ones were ancestral, and that Northeast would be colonized from them. Expansion range and allopatric fragmentation were historical events suggested as phylogeographic inferences to explain the current isolation of D. serido populations in Goiás and Minas Gerais. According to TMRCA estimations, it is possible that causal events of historical process inferred were related to the influence of climatic fluctuations during Quaternary in the geographic distribution range of vegetation/cacti, indirectly affecting the populations of cactofilic flies. Furthermore, selection events, associated with ecological factors due to cacti use, as well as contributed to diversification process in populations, once it was found evidence of positive selection at autosomal genes. (AU)

• FAPESP's process: 11/10499-7 - Evolutionary history of Drosophila serido ("cluster" Drosophila buzzatii)
• Grantee: Taís Carmona Lavagnini-Pizzo
• Support Opportunities: Scholarships in Brazil - Doctorate