Nervous systems display remarkable adaptability, rapidly evolving in response to environmental changes. The three closely-related drosophilids: D. melanogaster (Dmel), D. simulans (Dsim), and D. sechellia (Dsec) offer an ideal model for examining how ecological adaptations shape nervous system evolution. This drosophilid trio species exhibit distinct ecologies: Dmel and Dsim are cosmopolitan generalists, while the island endemic Dsec exhibits extreme niche specialism for ripe Morinda citrifolia (noni) fruit, providing an evolutionary context for their differences. To systematically investigate interspecific variability in nervous system cell types and gene expression, we applied single-nucleus RNA-sequencing (snRNA-seq) to the central brains, antennae, and developing antennal discs of this trio of species. With this dataset, we are addressing following questions: Is there interspecific variation in the composition and organization among drosophilid nervous systems (e.g., species-specific gain, loss or modification of neuronal populations)? How does gene expression evolve in conserved cell types (e.g., conservation or diversification of cell-type specific gene expression profiles)? What are the molecular and developmental mechanisms of species-specific remodeling of the nervous system (e.g., how genetic variants modify GRNs or that control neurodevelopment or functional properties of mature neurons)? How do changes in cell types and gene expression impact the neural circuits and behaviors of the species? The discovery of evolving neuronal and non-neuronal populations in this drosophilid trio will provide an entry point to more broadly study the evolvability of nervous systems across and beyond the Drosophila genus.
Single-cell and single-gene dissection of nervous system evolution in the ecological specialist Drosophila sechellia
Abstract ID: 139
Event: The 3rd AsiaEvo Conference
Topic: Genetics of adaptation and evolution of novel traits
Presenter Name: Daehan Lee