Abstract
Gene duplication followed by positive Darwinian selection is an important evolutionary event at the molecular level, by which a gene can gain new functions. Such an event might have occurred in the evolution of scorpion sodium channel toxin genes (α- and β-groups). To test this hypothesis, a robust statistical method from Yang and co-workers based on the estimation of the nonsynonymous-to-synonymous rate ratio (ω = d N/dS) was performed. The results provide clear statistical evidence for adaptive molecular evolution of scorpion α- and β-toxin genes. A good match between the positively selected sites (evolutionary epitopes) and the putative bioactive surface (functional epitopes) indicates that these sites are most likely involved in functional recognition of sodium channels. Our results also shed light on the importance of the B-loop in the functional diversification of scorpion α- and β-toxins.
Original language | English (US) |
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Pages (from-to) | 145-153 |
Number of pages | 9 |
Journal | Journal of Molecular Evolution |
Volume | 58 |
Issue number | 2 |
DOIs | |
State | Published - Feb 1 2004 |
Keywords
- Evolutionary epitopes
- Gene duplication
- Likelihood ratio test
- Positive Darwinian selection
- Scorpion toxin
- Sodium channel
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Molecular Biology
- Genetics