TY - JOUR T1 - Characterization of cephalic and non-cephalic sensory cell types provides insight into joint photo- and mechanoreceptor evolution JF - bioRxiv DO - 10.1101/2021.01.10.426124 SP - 2021.01.10.426124 AU - Roger Revilla-i-Domingo AU - Vinoth Babu Veedin Rajan AU - Monika Waldherr AU - Günther Prohaczka AU - Hugo Musset AU - Lukas Orel AU - Elliot Gerrard AU - Moritz Smolka AU - Matthias Farlik AU - Robert J. Lucas AU - Florian Raible AU - Kristin Tessmar-Raible Y1 - 2021/01/01 UR - http://biorxiv.org/content/early/2021/01/12/2021.01.10.426124.abstract N2 - Rhabdomeric Opsins (r-Opsins) are light-sensors in cephalic eye photoreceptors, but also function in additional sensory organs. This has prompted questions on the evolutionary relationship of these cell types, and if ancient r-Opsins cells were non-photosensory. Our profiling of cephalic and non-cephalic r-opsin1-expressing cells of the marine bristleworm Platynereis dumerilii reveals shared and distinct features. Non-cephalic cells possess a full set of phototransduction components, but also a mechanosensory signature. We determine that Pdu-r-Opsin1 is a Gαq-coupled blue-light receptor. Profiling of cells from r-opsin1 mutants versus wild-types, and a comparison under different light conditions reveals that in the non-cephalic cells, light – mediated by r-Opsin1 – adjusts the expression level of a calcium transporter relevant for auditory mechanosensation in vertebrates. We establish a deep learning-based quantitative behavioral analysis for animal trunk movements, and identify a light-and r-Opsin-1-dependent fine-tuning of the worm’s undulatory movements in headless trunks, which are known to require mechanosensory feedback.Our results suggest an evolutionary concept in which r-Opsins act as ancient, light-dependent modulators of mechanosensation, and suggest that light-independent mechanosensory roles of r-Opsins likely evolved secondarily. ER -