Die Rolle von Opsinen in Rezeptoren ausserhalb des Kopfes

Projekt: Forschungsförderung

Projektdetails

Abstract

Light-sensitive Opsin molecules have primarily been studied in the context of dedicated photoreceptors, as they
are present in animal eyes. This proposal focuses on two new and conceptually interesting aspects of Opsins:
First, cells related to animal eye photoreceptors have been discovered outside of the head of animals (referred to
as non-cephalic receptors). What is their function there? In particular, do these non-cephalic Opsin-positive cells
also respond to light, either on the electrophysiological level, and/or by modifying their cellular programme?
Secondly, evidence is growing that so-called rhabdomeric Opsins (r-Opsins) are also expressed – and, where
tested, even functionally required – in specific mechanoreceptive cells. This is in line with an old proposal that
extant mechano- and photoreceptive cells share a common evolutionary ancestor. But does this discovery
indicate a function of r-Opsin proteins distinct from (and possibly predating) photoreception? Or does it rather
point at an impact of light on mechanoreceptor function? These sets of questions have fundamental relevance for
both evolutionary biology (origin and diversification of sensory cells) and sensory biology.
The outlined project takes advantage of the discovery and stable fluorescent labeling of non-cephalic Opsinpositive
cells in the annelid bristleworm, Platynereis dumerilii, a model system that has proven to be highly
valuable for both evolutionary and comparative sensory biology. The project tackles the outlined questions
through three complementary approaches:
(i) Specific cell isolation by FACS and transcriptome profiling will directly test the effect of light on the programme
of non-cephalic cells.
(ii) Similarly, electrophysiological recordings will test if these cells are sensitive to light, mechanical stimuli, or a
combination of these.
(iii) Finally, matching results obtained in wild-type animals with results obtained in opsin-mutant strains will help
to dissect which of the effects require a functional opsin gene in these cells, and if opsin has regulatory /
modulatory functions.
The proposal can build on extensive prior work, strong technical expertise available to the team, and established
experimental procedures. For instance, the team already established a robust pipeline for dissociation, FACS,
transcriptome profiling, bioinformatic comparisons, and experimental validation. Likewise, the transgenic and
mutant strains required for this project are already generated, eliminating the need for additional preparation.
Given that molecularly related cells are present in both invertebrate and vertebrate systems, and that the cellular
make-up in Platynereis resembles a putative evolutionary precursor state of photo- and mechanoreceptors, the
proposed work has strong potential to provide new general insight of relevance for both sensory biology and
evolutionary biology.
Academic abstract
2402 - Raible
Creation
KurztitelDie Rolle von Opsinen in Rezeptoren ausserhalb des Kopfes
StatusAbgeschlossen
Tatsächlicher Beginn/ -es Ende1/01/1731/03/21

Schlagwörter

  • Evolution
  • Development
  • Photoreception
  • Opsin