在内布拉斯加的Sand Hill，那里的鹿鼠（deer mice）已经通过生长出类似的浅色毛皮而适应了它们的多尘且色浅的周围环境。

资料来源: Emily Kay

据8月28日的《科学》杂志报道说，在内布拉斯加的Sand Hill，那里的鹿鼠（deer mice）已经通过生长出类似的浅色毛皮而适应了它们的多尘且色浅的周围环境 – 据科研人员披露，这种特征来自某一基因突变，而该突变在Sand Hills形成之前尚未在该鼠中出现。 这一发现清楚地证明了，一种生物对某一新环境的快速适应并不总是依赖于在它们群体中的现有的基因变异，而是可能牵涉到包括遗传学、发育学和进化学在内的所有机制。

Catherine Linnen及其同僚对美国中西部的这些Sand Hills上的鹿鼠进行了研究，并将它们与附近的生活在土壤颜色较深地带的长着较深色毛皮的鹿鼠种群进行了对比。 研究人员在浅色鹿鼠中发现了一种以前不知道的毛皮颜色的模式，并发现它与某个特别基因（即Agouti基因）的突变有关。人们已知该基因对决定毛皮颜色起着作用。 他们提示，这种Agouti的颜色变化的突变与该基因中的一个单一氨基酸的缺失有关联（或是由其直接造成的）- 这种突变对Sand Hills上的鹿鼠带来了裨益。

推荐原始出处：

Science 28 August 2009:DOI: 10.1126/science.1175826

On the Origin and Spread of an Adaptive Allele in Deer Mice

Catherine R. Linnen,1,* Evan P. Kingsley,1 Jeffrey D. Jensen,2 Hopi E. Hoekstra1

Adaptation is a central focus of biology, although it can be difficult to identify both the strength and agent of selection and the underlying molecular mechanisms causing change. We studied cryptically colored deer mice living on the Nebraska Sand Hills and show that their light coloration stems from a novel banding pattern on individual hairs produced by an increase in Agouti expression caused by a cis-acting mutation (or mutations), which either is or is closely linked to a single amino acid deletion in Agouti that appears to be under selection. Furthermore, our data suggest that this derived Agouti allele arose de novo after the formation of the Sand Hills. These findings reveal one means by which genetic, developmental, and evolutionary mechanisms can drive rapid adaptation under ecological pressure.

1 Department of Organismic and Evolutionary Biology and the Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.
2 Center for Theoretical Evolutionary Genomics, Department of Integrative Biology, University of California, Berkeley, 3060 Valley Life Sciences Building, Berkeley, CA 94720, USA.