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High opsin diversity in a non-visual infaunal brittle star

BACKGROUND: In metazoans, opsins are photosensitive proteins involved in both vision and non-visual photoreception. Echinoderms have no well-defined eyes but several opsin genes were found in the purple sea urchin (Strongylocentrotus purpuratus) genome. Molecular data are lacking for other echinoder...

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Autores principales: Delroisse, Jérôme, Ullrich-Lüter, Esther, Ortega-Martinez, Olga, Dupont, Sam, Arnone, Maria-Ina, Mallefet, Jérôme, Flammang, Patrick
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4289182/
https://www.ncbi.nlm.nih.gov/pubmed/25429842
http://dx.doi.org/10.1186/1471-2164-15-1035
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author Delroisse, Jérôme
Ullrich-Lüter, Esther
Ortega-Martinez, Olga
Dupont, Sam
Arnone, Maria-Ina
Mallefet, Jérôme
Flammang, Patrick
author_facet Delroisse, Jérôme
Ullrich-Lüter, Esther
Ortega-Martinez, Olga
Dupont, Sam
Arnone, Maria-Ina
Mallefet, Jérôme
Flammang, Patrick
author_sort Delroisse, Jérôme
collection PubMed
description BACKGROUND: In metazoans, opsins are photosensitive proteins involved in both vision and non-visual photoreception. Echinoderms have no well-defined eyes but several opsin genes were found in the purple sea urchin (Strongylocentrotus purpuratus) genome. Molecular data are lacking for other echinoderm classes although many species are known to be light sensitive. RESULTS: In this study focused on the European brittle star Amphiura filiformis, we first highlighted a blue-green light sensitivity using a behavioural approach. We then identified 13 new putative opsin genes against eight bona fide opsin genes in the genome of S. purpuratus. Six opsins were included in the rhabdomeric opsin group (r-opsins). In addition, one putative ciliary opsin (c-opsin), showing high similarity with the c-opsin of S. purpuratus (Sp-opsin 1), one Go opsin similar to Sp-opsins 3.1 and 3.2, two basal-branch opsins similar to Sp-opsins 2 and 5, and two neuropsins similar to Sp-opsin 8, were identified. Finally, two sequences from one putative RGR opsin similar to Sp-opsin 7 were also detected. Adult arm transcriptome analysis pinpointed opsin mRNAs corresponding to one r-opsin, one neuropsin and the homologue of Sp-opsin 2. Opsin phylogeny was determined by maximum likelihood and Bayesian analyses. Using antibodies designed against c- and r-opsins from S. purpuratus, we detected putative photoreceptor cells mainly in spines and tube feet of A. filiformis, respectively. The r-opsin expression pattern is similar to the one reported in S. purpuratus with cells labelled at the tip and at the base of the tube feet. In addition, r-opsin positive cells were also identified in the radial nerve of the arm. C-opsins positive cells, expressed in pedicellariae, spines, tube feet and epidermis in S. purpuratus were observed at the level of the spine stroma in the brittle star. CONCLUSION: Light perception in A. filiformis seems to be mediated by opsins (c- and r-) in, at least, spines, tube feet and in the radial nerve cord. Other non-visual opsin types could participate to the light perception process indicating a complex expression pattern of opsins in this infaunal brittle star. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-1035) contains supplementary material, which is available to authorized users.
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spelling pubmed-42891822015-01-11 High opsin diversity in a non-visual infaunal brittle star Delroisse, Jérôme Ullrich-Lüter, Esther Ortega-Martinez, Olga Dupont, Sam Arnone, Maria-Ina Mallefet, Jérôme Flammang, Patrick BMC Genomics Research Article BACKGROUND: In metazoans, opsins are photosensitive proteins involved in both vision and non-visual photoreception. Echinoderms have no well-defined eyes but several opsin genes were found in the purple sea urchin (Strongylocentrotus purpuratus) genome. Molecular data are lacking for other echinoderm classes although many species are known to be light sensitive. RESULTS: In this study focused on the European brittle star Amphiura filiformis, we first highlighted a blue-green light sensitivity using a behavioural approach. We then identified 13 new putative opsin genes against eight bona fide opsin genes in the genome of S. purpuratus. Six opsins were included in the rhabdomeric opsin group (r-opsins). In addition, one putative ciliary opsin (c-opsin), showing high similarity with the c-opsin of S. purpuratus (Sp-opsin 1), one Go opsin similar to Sp-opsins 3.1 and 3.2, two basal-branch opsins similar to Sp-opsins 2 and 5, and two neuropsins similar to Sp-opsin 8, were identified. Finally, two sequences from one putative RGR opsin similar to Sp-opsin 7 were also detected. Adult arm transcriptome analysis pinpointed opsin mRNAs corresponding to one r-opsin, one neuropsin and the homologue of Sp-opsin 2. Opsin phylogeny was determined by maximum likelihood and Bayesian analyses. Using antibodies designed against c- and r-opsins from S. purpuratus, we detected putative photoreceptor cells mainly in spines and tube feet of A. filiformis, respectively. The r-opsin expression pattern is similar to the one reported in S. purpuratus with cells labelled at the tip and at the base of the tube feet. In addition, r-opsin positive cells were also identified in the radial nerve of the arm. C-opsins positive cells, expressed in pedicellariae, spines, tube feet and epidermis in S. purpuratus were observed at the level of the spine stroma in the brittle star. CONCLUSION: Light perception in A. filiformis seems to be mediated by opsins (c- and r-) in, at least, spines, tube feet and in the radial nerve cord. Other non-visual opsin types could participate to the light perception process indicating a complex expression pattern of opsins in this infaunal brittle star. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-1035) contains supplementary material, which is available to authorized users. BioMed Central 2014-11-28 /pmc/articles/PMC4289182/ /pubmed/25429842 http://dx.doi.org/10.1186/1471-2164-15-1035 Text en © Delroisse et al.; licensee BioMed Central. 2014 This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research Article
Delroisse, Jérôme
Ullrich-Lüter, Esther
Ortega-Martinez, Olga
Dupont, Sam
Arnone, Maria-Ina
Mallefet, Jérôme
Flammang, Patrick
High opsin diversity in a non-visual infaunal brittle star
title High opsin diversity in a non-visual infaunal brittle star
title_full High opsin diversity in a non-visual infaunal brittle star
title_fullStr High opsin diversity in a non-visual infaunal brittle star
title_full_unstemmed High opsin diversity in a non-visual infaunal brittle star
title_short High opsin diversity in a non-visual infaunal brittle star
title_sort high opsin diversity in a non-visual infaunal brittle star
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4289182/
https://www.ncbi.nlm.nih.gov/pubmed/25429842
http://dx.doi.org/10.1186/1471-2164-15-1035
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