Expression of pigmentation genes in the abdomen of Drosophila mediopunctata and its consequences for the pigmentation polymorphism

• Grant number: 13/04980-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2013
• End date: May 31, 2016
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: Louis Bernard Klaczko
• Grantee: Felipe Bastos Rocha
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Drosophila pigmentation is an important model for evolutionary and developmental studies that has revealed important features of genetic and developmental processes governing phenotypic evolution, such as the predominance of changes in cis regulatory elements over protein sequences. D. mediopunctata belongs to the tripunctata group of Drosophila and is, perhaps, the species that shows the widest range of phenotypic variation in a typical abdominal pigmentation pattern of the tripunctata group: phenotypes range from zero to three dark spots in the abdominal tergites. This polymorphism bears several features that make D. mediopunctata a good model for evolutionary developmental biology studies of pigmentation: chromosomes II and V affect the number of dark abdominal spots, but the second has a much greater effect; there is an association between the second chromosome inversion polymorphism and the pigmentation polymorphism; there is GxE interaction with the temperature; the variation of reaction norm and mean phenotypic value of this trait seem to be determined by pleiotropy. The aims of this project are to investigate the role of a set of pigmentation genes in the pigmentation pattern of D. mediopunctata; and also to try to find a locus with a major effect on the number of abdominal spots. We intend to: implement and standardize the analysis of gene expression with in situ hybridization in the laboratory; characterize the spatiotemporal gene expression pattern of a set of pigmentation genes in two D. mediopunctata strains with contrasting phenotypes; analyze the sequence variation in candidate loci in chromosomes II and V, searching for associations with the pigmentation polymorphism.