title: The comb jelly opsins and the origins of animal phototransduction.
abstract: Opsins mediate light detection in most animals, and understanding their evolution is key to clarify the origin of vision. Despite the public availability of a substantial collection of well-characterized opsins, early opsin evolution has yet to be fully understood, in large part because of the high level of divergence observed among opsins belonging to different subfamilies. As a result, different studies have investigated deep opsin evolution using alternative data sets and reached contradictory results. Here, we integrated the data and methods of three, key, recent studies to further clarify opsin evolution. We show that the opsin relationships are sensitive to outgroup choice; we generate new support for the existence of Rhabdomeric opsins in Cnidaria (e.g., corals and jellyfishes) and show that all comb jelly opsins belong to well-recognized opsin groups (the Go-coupled opsins or the Ciliary opsins), which are also known in Bilateria (e.g., humans, fruit flies, snails, and their allies) and Cnidaria. Our results are most parsimoniously interpreted assuming a traditional animal phylogeny where Ctenophora are not the sister group of all the other animals.
authors: Division of Biology and Biological Engineering, California Institute of Technology davide.pisani@bristol.ac.uk rfeuda@caltech.edu.
authors: Roberto
authors: R
authors: Feuda
authors: Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige (TN), Italy.
authors: Omar
authors: O
authors: Rota-Stabelli
authors: Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara.
authors: Todd H
authors: TH
authors: Oakley
authors: School of Biological Sciences and School of Earth Sciences, University of Bristol, United Kingdom davide.pisani@bristol.ac.uk rfeuda@caltech.edu.
authors: Davide
authors: D
authors: Pisani
mesh_terms: D000818:Animals; D003063:Cnidaria / Q000235:genetics* / Q000502:physiology; D037302:Ctenophora / Q000235:genetics* / Q000502:physiology; D019143:Evolution, Molecular; D055537:Light Signal Transduction; D055355:Opsins / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny
chemical_list: D055355:Opsins
keywords: Ctenophora; Metazoa; comb jelly; evolution; opsin; vision