改变基因结构的蚊子应对气候变迁生物谷
据国外媒体报道，俄勒冈大学的科学家利用DNA标签相关的排序技术，首次发现名叫“Wyeomyia ithii”蚊子通过改变基因结构来应对气候变迁。他们的研究结果已经发表在《美国国家科学院院刊》上。
图片来源：William Bradshaw / Christina Holzapfel
科学家利用DNA标签技术，研究了名叫“Wyeomyia ithii”的蚊子，这种蚊子起源于22000年到19000年前劳伦冰盖衰退期间的阿巴拉契亚山脉南部。这种蚊子生活在紫瓶子草（学名：Sarracenia purpurea）富含水的叶子里面。紫瓶子草广泛分布于寒冷地带，在其分布的地方，都可以发现这种名叫“Wyeomyia ithii”蚊子。
科学家通过研究发现，这种蚊子利用光周期反应来应对气候变化的基因机制，比如随着气候变化，可以改变休眠的时间、迁移甚至是繁殖时机。科学家称，因为蚊子对光周期的反应是一种遗传特征，因此它能够根据地球气温变化而进行调整的特性应该是遗传基因发生改变的结果。
美国国家科学基金会环境生物部山姆 沙伊纳（Sam Scheiner）是项目负责人，他说，这是迄今发现的第一种因为全球气候变化而发生基因改变的生物，这项研究成果可以用来研究由吸血蚊子作为传播媒介的登革热、脑炎等疾病。同时，这项技术可以用来研究人类进化机制
Resolving postglacial phylogeography using high-throughput sequencing
Kevin J. Emerson1, Clayton R. Merz, Julian M. Catchen, Paul A. Hohenlohe, William A. Cresko, William E. Bradshaw, and Christina M. Holzapfel
Center for Ecology and Evolutionary Biology, University of Oregon, Eugene, OR 97403-5289
The distinction between model and nonmodel organis is becoming increasingly blurred. High-throughput, second-generation sequencing approaches are being applied to organis based on their interesting ecological, physiological, developmental, or evolutionary properties and not on the depth of genetic information available for them. Here, we illustrate this point using a low-cost, efficient technique to determine the fine-scale phylogenetic relationships among recently diverged populations in a species. This application of restriction site-associated DNA tags (RAD tags) reveals previously unresolved genetic structure and direction of evolution in the pitcher plant mosquito, Wyeomyia ithii, from a southern Appalachian Mountain refugium following recession of the Laurentide Ice Sheet at 22,000–19,000 B.P. The RAD tag method can be used to identify detailed patterns of phylogeography in any organi regardless of existing genomic data, and, more broadly, to identify incipient speciation and genome-wide variation in natural populations in general.
