NEUROFLIES · Drosophila sechellia: a novel model to investigate nervous system and behavioral evolution

How animals’ extraordinarily diverse behaviors have evolved is unknown. Relating interspecific behavioral differences to anatomical or physiological distinctions in neural circuits, and causal genetic variation, offers a powerful approach to inform how nervous systems develop, function and change.Understanding behavioral and nervous system evolution requires deep investment in select species. We propose to establish a new model neurogenetic system: Drosophila sechellia, an island endemic that is closely related to D. melanogaster and D. simulans. While D. sechellia retains global genomic and superficial morphological similarity to its cosmopolitan generalist cousins, this species has adapted to a unique ecological niche, using Morinda fruit as a sole host for feeding and breeding. The project has three aims:Aim 1. Establishment of a D. sechellia (neuro)genetic toolkit: we will build essential genetic reagents for generation and maintenance of animals of desired genotypes, for neurogenetic manipulations, and for recombination mapping-based approaches.Aim 2. Behavioral, neuroanatomical and molecular phenomics: systematic comparison of D. sechellia, D. simulans and D. melanogaster for their behaviors, their neuroanatomy and their neuro-molecular expression properties will reveal how D. sechellia has adapted to its niche, and will provide multiple entry-points to relate molecular, neuronal and behavioral differences between these species.Aim 3. Defining the genetic basis and functional significance of a neuronal adaptation in D. sechellia: through high-resolution mapping and allele swap approaches, we will identify the causal genetic changes underlying a neural adaption in D. sechellia, and its physiological and behavioral significance.This project will establish a powerful new model system for evolutionary neuroscience (and many other fields) and provide fundamental insights into the origins and mechanisms of nervous system and behavioral diversification.