Differences in vertebrate microRNA expression
- Brandon Ason†,
- Diana K. Darnell‡,
- Beate Wittbrodt§,
- Eugene Berezikov†,
- Wigard P. Kloosterman†,
- Jochen Wittbrodt§,
- Parker B. Antin‡, and
- Ronald H. A. Plasterk†,¶
- †Hubrecht Laboratory, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands;
- ‡Department of Cell Biology and Anatomy, University of Arizona, Tucson, AZ 85724-5044; and
- §European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69012 Heidelberg, Germany
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Edited by Kathryn V. Anderson, Sloan–Kettering Institute, New York, NY, and approved August 8, 2006 (received for review April 30, 2006)
Abstract
MicroRNAs (miRNAs) attenuate gene expression by means of translational inhibition and mRNA degradation. They are abundant, highly conserved, and predicted to regulate a large number of transcripts. Several hundred miRNA classes are known, and many are associated with cell proliferation and differentiation. Many exhibit tissue-specific expression, which aids in evaluating their functions, and it has been assumed that their high level of sequence conservation implies a high level of expression conservation. A limited amount of data supports this, although discrepancies do exist. By comparing the expression of ≈100 miRNAs in medaka and chicken with existing data for zebrafish and mouse, we conclude that the timing and location of miRNA expression is not strictly conserved. In some instances, differences in expression are associated with changes in miRNA copy number, genomic context, or both between species. Variation in miRNA expression is more pronounced the greater the differences in physiology, and it is enticing to speculate that changes in miRNA expression may play a role in shaping the physiological differences produced during animal development.
Footnotes
- ¶To whom correspondence should be addressed. E-mail: plasterk{at}niob.knaw.nl
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Author contributions: B.A., D.K.D., E.B., P.B.A., and R.H.A.P. designed research; B.A., D.K.D., W.P.K., B.W., and E.B. performed research; B.A., D.K.D., B.W., E.B., W.P.K., J.W., P.B.A., and R.H.A.P. contributed new reagents/analytic tools; B.A., D.K.D., E.B., W.P.K., J.W., P.B.A., and R.H.A.P. analyzed data; and B.A. wrote the paper.
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The authors declare no conflict of interest.
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This paper was submitted directly (Track II) to the PNAS office.
- Abbreviations:
- miRNA,
- microRNA;
- dpf,
- days postfertilization;
- LNA,
- locked nucleic acid.
- © 2006 by The National Academy of Sciences of the USA
