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一个单一的氨基酸突变有助于适应性沙老鼠颜色模式
Hopi E Hoekstra1, Rachel J Hirschmann, Richard A Bundey
1Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA. hoekstra@ucsd.edu
Science (New York, N.Y.)
|July 11, 2006
概括
黑色皮质蛋白-1受体 (Mc1r) 的单个基因突变解释了野生海小鼠群体中显著的颜色变异. 这一发现将分子变化与自然环境中的适应性进化联系起来.
科学领域:
- 进化生物学是进化的生物学.
- 遗传学 是一个遗传学.
- 动物颜色动物的颜色.
背景情况:
- 与大陆亲属相比,沙小鼠显示出不同的颜色模式,这是由于伪装 (crypsis) 的自然选择所驱动的.
- 黑色皮质素-1受体 (Mc1r) 是一个关键的基因,参与着色素的形成.
- 在不同海岸的沙小鼠种群中,类似的光色的融合进化引发了关于潜在的遗传机制的问题.
研究的目的:
- 确定沙小鼠适应性颜色变化的遗传基础.
- 调查黑色皮质素-1受体 (Mc1r) 基因在沙小鼠颜色的作用.
- 探索孤立群体中色彩的融合进化背后的分子机制.
主要方法:
- 进行了基因交叉来分析色素特征的遗传性.
- 量化了Mc1r基因的等位基因变异,并与表型变异相关.
- 在不同的沙老鼠种群中评估了Mc1r等位基因的地理分布.
主要成果:
- 在沙小鼠中发现了Mc1r的衍生,电荷变化的氨基酸突变,减少了受体功能.
- 在七个色素特征的变异中,Mc1r等位基因变异占9.8%至36.4%.
- 在墨西哥湾沿岸的沙小鼠中发现了衍生的Mc1r等位基因,但在具有类似光色的大西洋海岸小鼠中没有.
结论:
- 在Mc1r中单个编码突变与野生沙老鼠种群的适应性定量变异有关.
- 不同的分子机制可能是地理上分离的沙老鼠群体中光色的融合进化的基础.
- 这项研究提供了特定基因突变与自然环境中的适应性表型进化之间的直接联系.
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