Phase distribution of spliceosomal introns: implications for intron origin
<p>Abstract</p> <p>Background</p> <p>The origin of spliceosomal introns is the central subject of the introns-early versus introns-late debate. The distribution of intron phases is non-uniform, with an excess of phase-0 introns. Introns-early explains this by speculatin...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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BMC
2006-09-01
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| Series: | BMC Evolutionary Biology |
| Online Access: | http://www.biomedcentral.com/1471-2148/6/69 |
| _version_ | 1798028393699082240 |
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| author | Yoshihama Maki Nguyen Hung D Kenmochi Naoya |
| author_facet | Yoshihama Maki Nguyen Hung D Kenmochi Naoya |
| author_sort | Yoshihama Maki |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>The origin of spliceosomal introns is the central subject of the introns-early versus introns-late debate. The distribution of intron phases is non-uniform, with an excess of phase-0 introns. Introns-early explains this by speculating that a fraction of present-day introns were present between minigenes in the progenote and therefore must lie in phase-0. In contrast, introns-late predicts that the nonuniformity of intron phase distribution reflects the nonrandomness of intron insertions.</p> <p>Results</p> <p>In this paper, we tested the two theories using analyses of intron phase distribution. We inferred the evolution of intron phase distribution from a dataset of 684 gene orthologs from seven eukaryotes using a maximum likelihood method. We also tested whether the observed intron phase distributions from 10 eukaryotes can be explained by intron insertions on a genome-wide scale. In contrast to the prediction of introns-early, the inferred evolution of intron phase distribution showed that the proportion of phase-0 introns increased over evolution. Consistent with introns-late, the observed intron phase distributions matched those predicted by an intron insertion model quite well.</p> <p>Conclusion</p> <p>Our results strongly support the introns-late hypothesis of the origin of spliceosomal introns.</p> |
| first_indexed | 2024-04-11T19:07:14Z |
| format | Article |
| id | doaj.art-5109c6890de54d0980ab959f93497c45 |
| institution | Directory Open Access Journal |
| issn | 1471-2148 |
| language | English |
| last_indexed | 2024-04-11T19:07:14Z |
| publishDate | 2006-09-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Evolutionary Biology |
| spelling | doaj.art-5109c6890de54d0980ab959f93497c452022-12-22T04:07:42ZengBMCBMC Evolutionary Biology1471-21482006-09-01616910.1186/1471-2148-6-69Phase distribution of spliceosomal introns: implications for intron originYoshihama MakiNguyen Hung DKenmochi Naoya<p>Abstract</p> <p>Background</p> <p>The origin of spliceosomal introns is the central subject of the introns-early versus introns-late debate. The distribution of intron phases is non-uniform, with an excess of phase-0 introns. Introns-early explains this by speculating that a fraction of present-day introns were present between minigenes in the progenote and therefore must lie in phase-0. In contrast, introns-late predicts that the nonuniformity of intron phase distribution reflects the nonrandomness of intron insertions.</p> <p>Results</p> <p>In this paper, we tested the two theories using analyses of intron phase distribution. We inferred the evolution of intron phase distribution from a dataset of 684 gene orthologs from seven eukaryotes using a maximum likelihood method. We also tested whether the observed intron phase distributions from 10 eukaryotes can be explained by intron insertions on a genome-wide scale. In contrast to the prediction of introns-early, the inferred evolution of intron phase distribution showed that the proportion of phase-0 introns increased over evolution. Consistent with introns-late, the observed intron phase distributions matched those predicted by an intron insertion model quite well.</p> <p>Conclusion</p> <p>Our results strongly support the introns-late hypothesis of the origin of spliceosomal introns.</p>http://www.biomedcentral.com/1471-2148/6/69 |
| spellingShingle | Yoshihama Maki Nguyen Hung D Kenmochi Naoya Phase distribution of spliceosomal introns: implications for intron origin BMC Evolutionary Biology |
| title | Phase distribution of spliceosomal introns: implications for intron origin |
| title_full | Phase distribution of spliceosomal introns: implications for intron origin |
| title_fullStr | Phase distribution of spliceosomal introns: implications for intron origin |
| title_full_unstemmed | Phase distribution of spliceosomal introns: implications for intron origin |
| title_short | Phase distribution of spliceosomal introns: implications for intron origin |
| title_sort | phase distribution of spliceosomal introns implications for intron origin |
| url | http://www.biomedcentral.com/1471-2148/6/69 |
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