Autor: |
Balakirev, ES, Anisimova, M, Ayala, FJ |
Jazyk: |
angličtina |
Rok vydání: |
2006 |
Zdroj: |
Balakirev, ES; Anisimova, M; & Ayala, FJ. (2006). Positive and negative selection in the β-esterase gene cluster of the Drosophila melanogaster subgroup. Journal of Molecular Evolution, 62(4), 496-510. doi: 10.1007/s00239-005-0140-1. UC Irvine: Retrieved from: http://www.escholarship.org/uc/item/2g3318jp |
DOI: |
10.1007/s00239-005-0140-1. |
Popis: |
We examine the pattern of molecular evolution of the β-esterase gene cluster, including the Est-6 and ψEst-6 genes, in eight species of the Drosophila melanogaster subgroup. Using maximum likelihood estimates of nonsynonymous/synonymous rate ratios, we show that the majority of Est-6 sites evolves under strong (48% of sites) or moderate (50% of sites) negative selection and a minority of sites (1.5%) is under significant positive selection. Est-6 sites likely to be under positive selection are associated with increased intraspecific variability. One positively selected site is responsible for the EST-6 F/S allozyme polymorphism; the same site is responsible for the EST-6 functional divergence between species of the melanogaster subgroup. For ψEst-6 83.7% sites evolve under negative selection, 16% sites evolve neutrally, and 0.3% sites are under positive selection. The positively selected sites of ψEst-6 are located at the beginning and at the end of the gene, where there is reduced divergence between D. melanogaster and D. simulans; these regions of ψEst-6 could be involved in regulation or some other function. Branch-site-specific analysis shows that the evolution of the melanogaster subgroup underwent episodic positive selection. Collating the present data with previous results for the β-esterase genes, we propose that positive and negative selection are involved in a complex relationship that may be typical of the divergence of duplicate genes as one or both duplicates evolve a new function. © Springer Science+Business Media, Inc. 2006. |
Databáze: |
OpenAIRE |
Externí odkaz: |
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