title: Global Transcriptome Analysis of the Tentacle of the Jellyfish Cyanea capillata Using Deep Sequencing and Expressed Sequence Tags: Insight into the Toxin- and Degenerative Disease-Related Transcripts.
abstract: BACKGROUND
  Jellyfish contain diverse toxins and other bioactive components. However, large-scale identification of novel toxins and bioactive components from jellyfish has been hampered by the low efficiency of traditional isolation and purification methods.
  
  
  RESULTS
  We performed de novo transcriptome sequencing of the tentacle tissue of the jellyfish Cyanea capillata. A total of 51,304,108 reads were obtained and assembled into 50,536 unigenes. Of these, 21,357 unigenes had homologues in public databases, but the remaining unigenes had no significant matches due to the limited sequence information available and species-specific novel sequences. Functional annotation of the unigenes also revealed general gene expression profile characteristics in the tentacle of C. capillata. A primary goal of this study was to identify putative toxin transcripts. As expected, we screened many transcripts encoding proteins similar to several well-known toxin families including phospholipases, metalloproteases, serine proteases and serine protease inhibitors. In addition, some transcripts also resembled molecules with potential toxic activities, including cnidarian CfTX-like toxins with hemolytic activity, plancitoxin-1, venom toxin-like peptide-6, histamine-releasing factor, neprilysin, dipeptidyl peptidase 4, vascular endothelial growth factor A, angiotensin-converting enzyme-like and endothelin-converting enzyme 1-like proteins. Most of these molecules have not been previously reported in jellyfish. Interestingly, we also characterized a number of transcripts with similarities to proteins relevant to several degenerative diseases, including Huntington's, Alzheimer's and Parkinson's diseases. This is the first description of degenerative disease-associated genes in jellyfish.
  
  
  CONCLUSIONS
  We obtained a well-categorized and annotated transcriptome of C. capillata tentacle that will be an important and valuable resource for further understanding of jellyfish at the molecular level and information on the underlying molecular mechanisms of jellyfish stinging. The findings of this study may also be used in comparative studies of gene expression profiling among different jellyfish species.
authors.affiliation: Marine Bio-pharmaceutical Institute, Second Military Medical University, Shanghai 200433, China.|Department of Marine Biotechnology, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, China.
authors.forename: Guoyan
authors.initials: G
authors.lastname: Liu
authors.affiliation: Marine Bio-pharmaceutical Institute, Second Military Medical University, Shanghai 200433, China.|Department of Marine Biotechnology, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Marine Bio-pharmaceutical Institute, Second Military Medical University, Shanghai 200433, China.|Department of Marine Biotechnology, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Liu
authors.affiliation: Marine Bio-pharmaceutical Institute, Second Military Medical University, Shanghai 200433, China.|Department of Marine Biotechnology, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Marine Bio-pharmaceutical Institute, Second Military Medical University, Shanghai 200433, China.|Department of Marine Biotechnology, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, China.
authors.forename: Zengliang
authors.initials: Z
authors.lastname: Ruan
authors.affiliation: Department of Gynecology, Third Affiliated Hospital, Second Military Medical University, Shanghai 200433, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: He
authors.affiliation: Marine Bio-pharmaceutical Institute, Second Military Medical University, Shanghai 200433, China.|Department of Marine Biotechnology, Faculty of Naval Medicine, Second Military Medical University, Shanghai 200433, China.
authors.forename: Liming
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000825:Animal Structures / Q000378:metabolism; D000818:Animals; D003064:Cnidarian Venoms / Q000235:genetics / Q000378:metabolism; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D008666:Metalloendopeptidases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D015260:Neprilysin / Q000235:genetics / Q000378:metabolism; D019636:Neurodegenerative Diseases / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D037401:Scyphozoa / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014361:Trypsin Inhibitors / Q000378:metabolism
chemical_list: D003064:Cnidarian Venoms; D014361:Trypsin Inhibitors; D008666:Metalloendopeptidases; D015260:Neprilysin; C071288:astacin