title: The transcriptome of the colonial marine hydroid Hydractinia echinata.
abstract: An increasing amount of expressed sequence tag (EST) and genomic data, predominantly for the cnidarians Acropora, Hydra and Nematostella, reveals that cnidarians have a high genomic complexity, despite being one of the morphologically simplest multicellular animals. Considering the diversity of cnidarians, we performed an EST project on the hydroid Hydractinia echinata, to contribute towards a broader coverage of this phylum. After random sequencing of almost 9000 clones, EST characterization revealed a broad diversity in gene content. Corroborating observations in other cnidarians, Hydractinia sequences exhibited a higher sequence similarity to vertebrates than to ecdysozoan invertebrates. A significant number of sequences were hitherto undescribed in metazoans, suggesting that these may be either cnidarian innovations or ancient genes lost in the bilaterian genomes analysed so far. However, we cannot rule out some degree of contamination from commensal bacteria. The identification of unique Hydractinia sequences emphasizes that the acquired genomic information generated so far is not large enough to be representative of the highly diverse cnidarian phylum. Finally, a database was created to store all the acquired information (http://www.mchips.org/hydractinia_echinata.html).
authors: Division of Functional Genome Analysis, Deutsches Krebsforschungszentrum, Heidelberg, Germany. j.sozaried@dkfz-heidelberg.de
authors: Jorge
authors: J
authors: Soza-Ried
authors: Agnes
authors: A
authors: Hotz-Wagenblatt
authors: Karl-Heinz
authors: KH
authors: Glatting
authors: Coral
authors: C
authors: del Val
authors: Kurt
authors: K
authors: Fellenberg
authors: Hans R
authors: HR
authors: Bode
authors: Uri
authors: U
authors: Frank
authors: Jörg D
authors: JD
authors: Hoheisel
authors: Marcus
authors: M
authors: Frohme
mesh_terms: D000818:Animals; D003063:Cnidaria / Q000145:classification / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D030541:Databases, Genetic; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D037402:Hydrozoa / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D013045:Species Specificity
chemical_list: D018076:DNA, Complementary