A combined computational and microarray-based approach identifies novel microRNAs encoded by human gamma-herpesviruses

  1. Adam Grundhoff1,3,
  2. Christopher S. Sullivan2,3, and
  3. Don Ganem2
  1. 1Heinrich-Pette Institut für experimentelle Virologie und Immunologie an der Universität Hamburg, D-20251 Hamburg, Germany
  2. 2Howard Hughes Medical Institute, Departments of Microbiology and Medicine, and G.W. Hooper Foundation, University of California, San Francisco, California 94143-0552, USA

Abstract

We have developed an approach to identify microRNAs (miRNAs) that is based on bioinformatics and array-based technologies, without the use of cDNA cloning. The approach, designed for use on genomes of small size (<2 Mb), was tested on cells infected by either of two lymphotropic herpesviruses, KSHV and EBV. The viral genomes were scanned computationally for pre-miRNAs using an algorithm (VMir) we have developed. Candidate hairpins suggested by this analysis were then synthesized as oligonucleotides on microarrays, and the arrays were hybridized with small RNAs from infected cells. Candidate miRNAs that scored positive on the arrays were then subjected to confirmatory Northern blot analysis. Using this approach, 10 of the known KSHV pre-miRNAs were identified, as well as a novel pre-miRNA that had earlier escaped detection. This method also led to the identification of seven new EBV-encoded pre-miRNAs; by using additional computational approaches, we identified a total of 18 new EBV pre-miRNAs that produce 22 mature miRNA molecules, thereby more than quadrupling the total number of hitherto known EBV miRNAs. The advantages and limitations of the approach are discussed.

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Footnotes

  • 3

    3 These authors contributed equally to this work.

  • Reprint requests to: Adam Grundhoff, Heinrich-Pette Institut für experimentelle Virologie und Immunologie an der Universität Hamburg, Martinistrasse 52, D-20251 Hamburg, Germany; e-mail: adam.grundhoff{at}hpi.uni-hamburg.de; fax: +49-40-48051-296.

  • Article published online ahead of print. Article and publication date are at http://www.rnajournal.org/cgi/doi/10.1261/rna.2326106.

    • Received December 13, 2005.
    • Accepted January 19, 2006.
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