Genetic and circuit bases of mechanically-induced predator avoidance in Platynereis dumerilii larvae
Sensory and Behavioural Biology
Final Report Abstract
Startle responses triggered by aversive stimuli including predators are widespread across animals. These coordinated whole-body actions require the rapid and simultaneous activation of a large number of muscles. In this project, we investigated a startle response in the planktonic larva of the marine annelid Platynereis dumerilii to understand the whole-body circuit implementation of the behaviour. Upon encountering water vibrations, Platynereis larvae close their locomotor cilia and simultaneously raise the parapodia. The response is mediated by collar receptor neurons expressing the polycystins PKD1-1 and PKD2-1. CRISPR-generated PKD1-1 and PKD2-1 mutant larvae do not startle and fall prey to a copepod predator at a higher rate. Reconstruction of the whole-body connectome of the collar-receptor-cell circuitry revealed converging feedforward circuits to the ciliary bands and muscles. The wiring diagram suggests circuit mechanisms for the intersegmental and leftright coordination of the response. Our results reveal how polycystin-mediated mechanosensation can trigger a coordinated whole-body effector response involved in predator avoidance.
Publications
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Ciliomotor circuitry underlying whole-body coordination of ciliary activity in the Platynereis larva. Elife. 2017 May 16;6:e26000
Verasztó C, Ueda N, Bezares-Calderón LA, Panzera A, Williams EA, Shahidi R, Jékely
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Neural circuitry of a polycystin-mediated hydrodynamic startle response for predator avoidance. Elife. 2018 Dec 14;7:e36262
Bezares-Calderón LA, Berger J, Jasek S, Verasztó C, Mendes S, Gühmann M, Almeda R, Shahidi R, Jékely G
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Diversity of cilia-based mechanosensory systems and their functions in marine animal behaviour. Philos Trans R Soc Lond B Biol Sci. 2020 Feb 17;375(1792):20190376
Bezares-Calderón LA, Berger J, Jékely G
