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Weak negative and positive selection and the drift load at splice sitesстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 27 мая 2015 г.
- Авторы: Denisov Stepan V., Bazykin Georgii A., Sutormin Roman, Favorov Alexander V., Mironov Andrey A., Gelfand Mikhail S., Kondrashov Alexey S.
- Журнал: Genome biology and evolution
- Том: 6
- Номер: 6
- Год издания: 2014
- Издательство: Oxford University Press
- Местоположение издательства: United Kingdom
- Первая страница: 1437
- Последняя страница: 1447
- DOI: 10.1093/gbe/evu100
- Аннотация: Splice sites (SSs) are short sequences that are crucial for proper mRNA splicing in eukaryotic cells, and therefore can be expected to be shaped by strong selection. Nevertheless, in mammals and in other intron-rich organisms, many of the SSs often involve nonconsensus (Nc), rather than consensus (Cn), nucleotides, and beyond the two critical nucleotides, the SSs are not perfectly conserved between species. Here, we compare the SS sequences between primates, and between Drosophila fruit flies, to reveal the pattern of selection acting at SSs. Cn-to-Nc substitutions are less frequent, and Nc-to-Cn substitutions are more frequent, than neutrally expected, indicating, respectively, negative and positive selection. This selection is relatively weak (1 < |4Nes| < 4), and has a similar efficiency in primates and in Drosophila. Within some nucleotide positions, the positive selection in favor of Nc-to-Cn substitutions is weaker than the negative selection maintaining already established Cn nucleotides; this difference is due to site-specific negative selection favoring current Nc nucleotides. In general, however, the strength of negative selection protecting the Cn alleles is similar in magnitude to the strength of positive selection favoring replacement of Nc alleles, as expected under the simple nearly neutral turnover. In summary, although a fraction of the Nc nucleotides within SSs is maintained by selection, the abundance of deleterious nucleotides in this class suggests a substantial genome-wide drift load.
- Добавил в систему: Базыкин Георгий Александрович