Abstract:
:Identification of recently gained spliceosomal introns would provide crucial evidence in the continuing debate concerning the age and evolutionary significance of introns. A previously published genomic analysis reported to have identified 122 introns that had been gained since the divergence of the nematodes Caenorhabidits elegans and Caenorhabditis briggsae approximately 100 MYA. However, using newly available genomic sequence from additional Caenorhabditis species, we show that 74% (60/81) of the reported gains in C. elegans are present in a C. briggsae relative. This pattern indicates that these introns represent losses in C. briggsae, not gains in C. elegans. In addition, 61% (25/41) of the reported gains in C. briggsae are present in the more distant C. briggsae relative, in a pattern suggesting that additional reported gains in C. elegans and/or C. briggsae may in fact represent unrecognized losses. These results underscore the dominance of intron loss over intron gain in recent eukaryotic evolution, the pitfalls associated with parsimony in inferring intron gains, and the importance of genomic sequencing of clusters of closely related species for drawing accurate inferences about genome evolution.
journal_name
Mol Biol Evoljournal_title
Molecular biology and evolutionauthors
Roy SW,Penny Ddoi
10.1093/molbev/msl098subject
Has Abstractpub_date
2006-12-01 00:00:00pages
2259-62issue
12eissn
0737-4038issn
1537-1719pii
msl098journal_volume
23pub_type
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pub_type: 杂志文章
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更新日期:2010-06-01 00:00:00
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pub_type: 杂志文章
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更新日期:1987-05-01 00:00:00
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