serval:BIB_8BD867F10599
Olfactory receptor and circuit evolution promote host specialization
10.1038/s41586-020-2073-7
32132713
Auer
T. O.
author
Khallaf
M. A.
author
Silbering
A. F.
author
Zappia
G.
author
Ellis
K.
author
Álvarez-Ocaña
R.
author
Arguello
J. R.
author
Hansson
B. S.
author
Jefferis
G. S. X. E.
author
Caron
S. J. C.
author
Knaden
M.
author
Benton
R.
author
article
2020-03
Nature
1476-4687
0028-0836
journal
579
7799
402-408
The evolution of animal behaviour is poorly understood <sup>1,2</sup> . Despite numerous correlations between interspecific divergence in behaviour and nervous system structure and function, demonstrations of the genetic basis of these behavioural differences remain rare <sup>3-5</sup> . Here we develop a neurogenetic model, Drosophila sechellia, a species that displays marked differences in behaviour compared to its close cousin Drosophila melanogaster <sup>6,7</sup> , which are linked to its extreme specialization on noni fruit (Morinda citrifolia) <sup>8-16</sup> . Using calcium imaging, we identify olfactory pathways in D. sechellia that detect volatiles emitted by the noni host. Our mutational analysis indicates roles for different olfactory receptors in long- and short-range attraction to noni, and our cross-species allele-transfer experiments demonstrate that the tuning of one of these receptors is important for species-specific host-seeking. We identify the molecular determinants of this functional change, and characterize their evolutionary origin and behavioural importance. We perform circuit tracing in the D. sechellia brain, and find that receptor adaptations are accompanied by increased sensory pooling onto interneurons as well as species-specific central projection patterns. This work reveals an accumulation of molecular, physiological and anatomical traits that are linked to behavioural divergence between species, and defines a model for investigating speciation and the evolution of the nervous system.
Multidisciplinary
eng
60_published
true
peer-reviewed
Publication types: Comparative Study ; Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
University of Lausanne
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