Identification of Mammalian microRNA Host Genes and Transcription Units

  1. Antony Rodriguez,
  2. Sam Griffiths-Jones,
  3. Jennifer L. Ashurst, and
  4. Allan Bradley1
  1. Wellcome Trust Sanger Institute, The Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom

Abstract

To derive a global perspective on the transcription of microRNAs (miRNAs) in mammals, we annotated the genomic position and context of this class of noncoding RNAs (ncRNAs) in the human and mouse genomes. Of the 232 known mammalian miRNAs, we found that 161 overlap with 123 defined transcription units (TUs). We identified miRNAs within introns of 90 protein-coding genes with a broad spectrum of molecular functions, and in both introns and exons of 66 mRNA-like noncoding RNAs (mlncRNAs). In addition, novel families of miRNAs based on host gene identity were identified. The transcription patterns of all miRNA host genes were curated from a variety of sources illustrating spatial, temporal, and physiological regulation of miRNA expression. These findings strongly suggest that miRNAs are transcribed in parallel with their host transcripts, and that the two different transcription classes of miRNAs (`exonic' and `intronic') identified here may require slightly different mechanisms of biogenesis.

Footnotes

  • [Supplemental material is available online at www.genome.org.]

  • Article and publication are at http://www.genome.org/cgi/doi/10.1101/gr.2722704. Article published online before print in September 2004.

  • 1 Corresponding author. E-MAIL abradley{at}sanger.ac.uk; FAX 44-1223-494714.

    • Accepted July 27, 2004.
    • Received April 28, 2004.
| Table of Contents

Preprint Server