English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/13521
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:


Metagenomic retrieval of a ribosomal DNA repeat array from an uncultured marine alveolate

AuthorsMassana, Ramon ; Karniol, Baruch; Pommier, Thomas ; Bodaker, Idan; Béjà, Oded
Issue Date3-Feb-2008
PublisherBlackwell Publishing
CitationEnvironmental Microbiology 10(5): 1335-1343 (2008)
AbstractThe aim of this study was to explore the use of large-scale sequencing to better describe the genome content of naturally occurring, uncultured protists. We constructed a metagenomic fosmid library from a picoplanktonic assemblage (0.2–3 mm size cells) collected at the Blanes Bay Microbial Observatory (Western Mediterranean). Seven clones contained a small-subunit ribosomal RNA gene (SSU rDNA) affiliating with prasinophytes and uncultured alveolates. One clone (FBB25; 35 kb in size) was completely sequenced and found to be a tandem repeat array (5.5 times) of the rDNA operon, including three rRNA genes (SSU, large-subunit and 5.8S rDNAs) and three spacer regions (internal transcribed spacers 1, 2 and intergenic spacer). The SSU rDNA of FBB25 affiliated with the marine alveolates group I, cluster 1, and was almost identical to sequences retrieved only in marine surveys from a wide geographic and ecological range. Phylogenetic trees using the different rRNA genes showed FBB25 as an independent branch among the main alveolate groups, but their closest affiliation varied between the SSU tree (dinoflagellates) and the large-subunit and 5.8S trees (perkinsids). The spacer regions of FBB25 were particularly short when compared with other eukaryotes, indicating a possible genome streamlining in this picoeukaryote. Finally, not a single polymorphism was found in the rDNA repeat array, suggesting that the high SSU rDNA variability typically found in molecular surveys derives from organismal and not intragenomic diversity. This first report on the rDNA genomic structure of an uncultured marine alveolate improves their phylogenetic position and helps interpreting data generated during picoeukaryotic molecular surveys
Description9 pages, 4 figures, 1 table.-- PMID: 18266757 [PubMed]
Publisher version (URL)http://dx.doi.org/10.1111/j.1462-2920.2007.01549.x
Appears in Collections:(ICM) Artículos
Files in This Item:
There are no files associated with this item.
Show full item record
Review this work

Related articles:

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.