非编码DNA的适应性进化在Drosophila中
1Section of Ecology, Behavior and Evolution, Division of Biological Sciences, University of California San Diego, La Jolla, California 92093, USA. pandolfatto@ucsd.edu
Nature
|October 21, 2005
概括
果中非编码DNA的很大一部分在功能上很重要,在约束和积极选择下演变. 这表明,在进化过程中,非编码DNA的适应性变化是常见的.
科学领域:
- 进化生物学是进化的生物学.
- 基因组学就是基因组学.
- 分子进化的分子进化.
背景情况:
- 细胞基因组含有很大比例的非编码DNA,其功能在很大程度上是未知的.
- 了解非编码DNA的进化动态对于完整了解基因组进化至关重要.
研究的目的:
- 研究Drosophila各种类非编码DNA的进化速率和选择性压力.
- 确定非编码基因组区域的功能重要性和适应性进化的程度.
主要方法:
- 从不同的Drosophila物种中对DNA序列进行比较分析.
- 应用扩展的麦当劳-克莱特曼测试,以区分净化和积极选择.
- 通过将非编码DNA进化与同名站点进行比较,估计进化约束.
主要成果:
- 非编码的DNA区域 (跨基因,UTR,内基) 的进化速度比同名位点慢,这表明有选择性约束.
- 显著超过多态的分歧表明这些地区的适应性进化.
- 估计显示,40-70%的非编码核酸受到约束,而20-60%的分歧是由积极选择驱动的.
结论:
- 很大一部分非编码DNA具有功能意义,并由净化和适应性进化形成.
- 非编码DNA中的适应性进化可能比以前认为的在Drosophila melanogaster进化中更为普遍.
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