Skip Navigation



MBE Advance Access published online on March 13, 2008
Molecular Biology and Evolution, doi:10.1093/molbev/msn060
This Article
Right arrow Advance Access manuscript (PDF)
Right arrow Supplementary Data
Right arrow Supplementary Data
Right arrow All Versions of this Article:
25/6/1067    most recent
msn060v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Fu, X.
Right arrow Articles by Thompson, E. M.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Fu, X.
Right arrow Articles by Thompson, E. M.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2008. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oxfordjournals.org

research article

Altered miRNA Repertoire in the Simplified Chordate, Oikopleura dioica.

Xianghui Fu, Marcin Adamski and Eric M. Thompson*

Sars Centre for Marine Molecular Biology, Bergen High Technology Centre, University of Bergen, Thormøhlensgate 55, N-5008 Bergen, Norway

* To whom correspondence should be addressed: Eric M. Thompson, Tel: 47-55.58.43.46, Fax: 47-55.58.43.05, email: Eric.Thompson{at}sars.uib.no

Received for publication October 22, 2007. Revision received January 31, 2008. Accepted for publication February 11, 2008.

Recent studies reveal correlation between miRNA innovation and increased developmental complexity. This is exemplified by dramatic expansion of the miRNA inventory in vertebrates, a lineage where genome duplication has played a significant evolutionary role. Urochordates, the closest extant group to the vertebrates, exhibit an opposite trend to genome and morphological simplification. We show that the urochordate, larvacean, Oikopleura dioica, possesses the requisite miRNA biogenic machinery. miRNAs isolated by small RNA cloning were expressed throughout the short life cycle, a number of which were stocked as maternal determinants prior to rapid embryonic development. We identify sex-specific miRNAs that appeared as male/female gonad differentiation became apparent and were maintained throughout spermatogenesis. Whereas 80% of mammalian miRNAs are hosted in introns of protein-coding genes, the majority of O. dioica miRNA loci were located in anti-sense orientations to such genes. Including sister group ascidians in analysis of the urochordate miRNA repertoire, we find 11 highly conserved bilaterian miRNA families have been lost or derived to the point they are not recognizable in urochordates and a further 4 of these families are absent in larvaceans . Subsequent to this loss/derivation, at least 29 novel miRNA families have been acquired in larvaceans. This suggests a profound reorganization of the miRNA repertoire integral to evolution in the urochordate lineage.

Key Words: ncRNA • let-7 • P-body • Drosha • larvacean • ascidian


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.