Speaker
Description
Understanding how sensory organs evolve is a central question in sensory biology and evolutionary neuroscience. Due to their complexity, comprehensive analysis of entire sensory organs has been challenging. Here, we leverage the relative simplicity of the Drosophilid maxillary palps: olfactory organs critical for odor-guided behavior
and host-seeking. In Drosophila melanogaster, these organs comprise only six neuronal types organized into three stereotypical sensillum types, offering a tractable system for evolutionary analysis.
Using a combination of cross-species transcriptomics, receptor expression profiling, and genetic tools, we uncover fundamental mechanisms driving olfactory organ evolution. Our findings reveal widespread co-option of olfactory receptors across organs and life stages. We dissect the genetic basis of evolutionary shift and identify key changes in cis-regulatory elements in one of these receptors. Importantly,we identify a specific neuronal cell type that consistently serves as a hotspot for evolutionary changes in receptor expression across species. Furthermore, by examining species spanning broad evolutionary distances, we identify the mergence of novel neuron types, characterize evolutionary intermediates, and show that while receptor expression is highly adaptable, the evolution of new cell types is more constrained.
Altogether, our work provides new insight into how sensory organs evolve,
highlighting both conserved and adaptable components of olfactory system
architecture.
