Skip Navigation


MBE Advance Access first published online on October 27, 2007
This version published online on November 20, 2007
Molecular Biology and Evolution, doi:10.1093/molbev/msm235
This Article
Right arrow Advance Access manuscript (PDF)
Right arrow Supplementary Material
Right arrow All Versions of this Article:
24/12/2842-a    most recent
msm235v5
msm235v4
msm235v3
msm235v2
msm235v1
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 Coulombe-Huntington, J.
Right arrow Articles by Majewski, J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Coulombe-Huntington, J.
Right arrow Articles by Majewski, J.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2007. 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

Intron Loss and Gain in Drosophila

Jasmin Coulombe-Huntington and Jacek Majewski

Department of Human Genetics, McGill University, Montreal, QC, Canada

Corresponding author: Jacek Majewski, Email: jacek.majewski{at}mcgill.ca

Received for publication September 13, 2007. Revision received October 11, 2007. Accepted for publication October 22, 2007.

Although introns were first discovered almost 30 years ago, their evolutionary origin remains elusive. In this work, we used multi-species whole-genome alignments to map Drosophila melanogaster introns onto 10 other fully sequenced Drosophila genomes. We were able to find 1944 sites where an intron was missing in one or more species. We show that for most (>80%) of these cases, there is no leftover intronic sequence or any missing exonic sequence, indicating exact intron loss or gain events. We used parsimony to classify these differences as 1754 intron loss events and 213 gain events. We show that lost and gained introns are significantly shorter than average and flanked by longer than average exons. They also display quite distinct phase distributions and show greater than average similarity between the 5' splice-site and its 3' partner splice-site. Introns that have been lost in one or more species evolve faster than other introns, occur in slowly evolving genes and are found adjacent to each other more often then would be expected for independent single-losses. Our results support the cDNA recombination mechanism of intron loss, suggest that selective pressures affect site-specific loss rates and show conclusively that intron gain has occurred within the Drosophila lineage, solidifying the "introns-middle" hypothesis and providing some hints about the gain mechanism.

Key Words: Intron loss • intron gain • intron dynamics • drosophila • comparative genomics


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


This article has been cited by other articles:


Home page
 Proc. Natl. Acad. Sci. USAHome page
R. Tarrio, F. J. Ayala, and F. Rodriguez-Trelles
From the Cover: Alternative splicing: A missing piece in the puzzle of intron gain
PNAS, May 20, 2008; 105(20): 7223 - 7228.
[Abstract] [Full Text] [PDF]


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.