Prevalence of the bacterial endossymbiont Wolbachia on neotropical drosophilid comunities

Author(s)

Marcos Aurélio Martins Oliveira da Silva

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
• Defense date: 2021-07-23

Examining board members

Rodrigo Cogni; Ana Paula Aprigio Assis; Marcos Roberto Dias Batista; Leonardo Re Jorge

• Advisor: Rodrigo Cogni

Abstract

Selfish interests put maternally transmitted endosymbionts and host-nuclear genome into conflict. Wolbachia is an example of a remarkably successful endosymbiont present in 50% of all arthropods. One process that explains its high prevalence is its ability to manipulate host reproduction to its own favor through cytoplasmic incompatibility. The rapid spread of Wolbachia in Drosophila species populations was observed in real-time; however, it was shown that some successful Wolbachia strains maintain high frequencies regardless of manipulation, suggesting that a mutualistic effect may maintain its high prevalence in natural populations. Intriguingly, Wolbachia frequency variation in natural host populations correlates with environmental gradients. The present study describes the prevalence of Wolbachia in eight different neotropical drosophilid communities from the Atlantic Forest and queries whether community ecological factors, beyond phylogenetic factors, can improve the probability of explaining if an individual carry Wolbachia. By using generalized mixed logistic regressions, our proposed model that includes ecological factors species abundance, season, and altitude does not improve the explanation of the odds of Wolbachia occurrence. Alternatively, our null model containing only the random effects species and species group shows an intraclass correlation coefficient that explains about 40% of chance of clade components predicting Wolbachia occurrence. Our results suggest that the impact of ecology in Wolbachia-host interaction is overshadowed by the strength of selection operating at the level of genes that mediate manipulation phenotype and host shift, these results might classify Wolbachia as a passenger of passengers. (AU)

• FAPESP's process: 18/01295-8 - Quantitative description of a drosophilid community and its natural enemies in an Atlantic Forest altitudinal gradient
• Grantee: Marcos Aurélio Martins Oliveira da Silva
• Support Opportunities: Scholarships in Brazil - Master