The genetic bases of quantitative morphological variation in a population of Drosophila

• Applicant: Professor Dr. Nicolas Gompel
• Subject Area: Evolutionary Cell and Developmental Biology (Zoology) ; General Genetics and Functional Genome Biology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 545438816

Morphological differences between species may find their origin in standing genetic variation available in populations of their common ancestor. To conceptually link these two evolutionary timescales –populations and species– in terms of genetic mechanisms underlying morphological variation, we are comparing pigmentation variation on fly wings among closely related species, to pigmentation variation in a population of one of these species. Our previous work paints a fairly detailed picture of the genetic origin of inter-species differences, such as a spot of dark pigmentation at the wing tip. The present project aims at deciphering the genetic origin of variation in wing pigmentation within a population of a single species with a wing spot, Drosophila biarmipes. Our specific aims are to: (i) evaluate the correlation between morphological and genetic diversity in our population (ii) identify loci at the genome-wide scale underlying quantitative variation in wing pigmentation within a population, (iii) evaluate the role of regulatory variation at a pigmentation gene of particular interest in the modulation of wing pigmentation within a population To address these aims, we propose to combine our expertise in population and quantitative genetics (French team) and in functional genetics and evolutionary developmental biology (German team). We will organize our research into three work packages (WPs). We will first (WP1) evaluate the population genetics parameters (existing polymorphism, heritability) of the study population in order to optimize the design of subsequent genetic mapping and afford a high mapping resolution. We will then carry out a Genome-Wide Association Study (GWAS) based on single fly genomes (WP2). To maximize the phenotyping power, we will average the phenotypes (wing pigmentation) of several specimens in the progeny of each sequenced fly. Finally (WP3), we will validate the involvement of candidate loci identified in the mapping using functional genetic assays. We will particularly scrutinize the possible role of the gene yellow in pigmentation variation at the population level, as we recently found that regulatory changes at this gene explain continuous variation in wing pigmentation among species. Our joint effort at the interface of population genetics and Evo-Devo will result in the possibility to compare the genetic make-up of phenotypic changes among species to the genetic architecture of variation within species.

• DFG Programme: Research Grants
• International Connection: France
• Partner Organisation: Agence Nationale de la Recherche / The French National Research Agency
• Cooperation Partner: Mathieu Gautier, Ph.D.