title: De novo transcriptome of the European brittle star Amphiura filiformis pluteus larvae.
abstract: BACKGROUND
  In non-classical model species, Next Generation Sequencing increases the ability to analyze the expression of transcripts/genes. In this study, paired-end Illumina HiSeq sequencing technology has been employed to describe a larval transcriptome generated from 64 h post-fertilization pluteus larvae of the brittle star Amphiura filiformis. We focused our analysis on the detection of actors involved in the opsin based light perception, respectively the opsins and the phototransduction actors.
  
  
  RESULTS
  In this research, about 47 million high quality reads were generated and 86,572 total unigenes were predicted after de novo assembly. Of all the larval unigenes, 18% show significant matches with reference online databases. 46% of annotated larval unigenes were significantly similar to transcripts from the purple sea urchin. COG, GO and KEGG analyses were performed on predicted unigenes. Regarding the opsin-based photoreception process, even if possible actors of ciliary and rhabdomeric phototransduction cascades were detected, no ciliary or rhabdomeric opsin was identified in these larvae. Additionally, partial non-visual RGR (retinal G protein coupled receptor) opsin mRNAs were identified,possibly indicating the presence of visual cycle reaction in early pluteus larvae. The eye morphogene Pax 6 was also identified in the pluteus transcriptome.
  
  
  CONCLUSIONS
  Contrary to sea-urchin larvae, brittle star larvae appear to be characterized by an absence of visual-like opsins. These RNA-seq data also provide a useful resource for the echinoderm research community and researchers with an interest in larval biology.
authors.affiliation: University of Mons - UMONS, Research Institute for Biosciences, Biology of Marine Organisms and Biomimetics, 23 Place du Parc, 7000 Mons, Belgium. Electronic address: jerome.delroisse@umons.ac.be.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Delroisse
authors.affiliation: University of Gothenburg, Department of Biological and Environmental Science, The Sven Lovén Centre for Marine Sciences, Kristineberg, 45178 Fiskebäckskil, Sweden. Electronic address: olga.ortega-martinez@bioenv.gu.se.
authors.forename: Olga
authors.initials: O
authors.lastname: Ortega-Martinez
authors.affiliation: University of Gothenburg, Department of Biological and Environmental Science, The Sven Lovén Centre for Marine Sciences, Kristineberg, 45178 Fiskebäckskil, Sweden. Electronic address: sam.dupont@bioenv.gu.se.
authors.forename: Sam
authors.initials: S
authors.lastname: Dupont
authors.affiliation: Catholic University of Louvain-La-Neuve, Marine Biology Laboratory, Place croix du Sud, Louvain-La-Neuve, Belgium. Electronic address: jerome.mallefet@uclouvain.be.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Mallefet
authors.affiliation: University of Mons - UMONS, Research Institute for Biosciences, Biology of Marine Organisms and Biomimetics, 23 Place du Parc, 7000 Mons, Belgium. Electronic address: patrick.flammang@umons.ac.be.
authors.forename: Patrick
authors.initials: P
authors.lastname: Flammang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003198:Computer Simulation; D020451:Contig Mapping; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000378:metabolism; D008027:Light; D008969:Molecular Sequence Data; D055355:Opsins / Q000235:genetics / Q000378:metabolism; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D013215:Starfish / Q000235:genetics*; D059467:Transcriptome
chemical_list: D005136:Eye Proteins; D018398:Homeodomain Proteins; D055355:Opsins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins
keywords: Echinodermata; Larval stage; Paired-end Illumina Sequencing; Photoreception; RGR opsin; Transcriptome