Molecular Studies of Cophylogeny: Microbes, Insects, and Mammals

mark S. hafner博士；路易斯安那州立大学的动物学家马克·s·哈夫纳（Mark S. Hafner）和微生物学家马克·s·哈夫纳（Mark S. Hafner）博士。同一研究所的弗雷德里克·雷尼和娜奥米·沃德-雷尼获得了一笔资助，研究三种共生生物的共同进化史：一种叫做口袋地鼠的小啮齿动物，生活在口袋地鼠皮毛中的虱子，以及生活在虱子内部的选定细菌。Hafner和他的同事之前的研究已经确定口袋地鼠和它们的虱子已经在一起生活了数百万年，导致了口袋地鼠和虱子几乎相同的系统发育（家谱）。现在，合作小组建议使用分子方法，包括检查DNA和RNA，来确定生活在虱子体内的细菌是否也与它们的宿主有着悠久的联系历史。这个为期两年的项目的主要目标是描述生活在虱子内部的细菌群落，并区分在虱子内部或多或少永久生活的细菌谱系与那些仅仅短暂通过虱子消化道的细菌谱系。这项研究将需要仔细检查和比较虱子内和虱子外（地鼠相关和自由生活）的细菌群落；因此，本研究的一个重要副产品将是表征与整个口袋地鼠洞穴系统相关的微生物群落。实验方法将包括三条证据线：虱子内微生物群落的微观可视化，细菌谱系的培养和DNA测序，以及细菌多样性的培养独立分子分析。最终，对细菌和宿主之间长期联系的记录将允许比较这两个远亲群体的遗传变化率。

DEB-0075381Mark S. HafnerDr. Mark S. Hafner, a zoologist at Louisiana State University, along with microbiologists Drs. Frederick Rainey and Naomi Ward-Rainey at the same institution have been awarded a grant to investigate the shared evolutionary history of three symbiotic organisms: small rodents called pocket gophers, the lice that live in the fur of the pocket gophers, and selected lineages of bacteria that live inside the lice. Previous research by Hafner his other colleagues has established that the pocket gophers and their lice have been living together for millions of years, resulting in nearly identical phylogenies (family trees) for the gophers and lice. The presence collaborative team now proposes to use molecular methods, including examination of DNA and RNA, to determine if the bacteria that live inside the lice also have shared a long history of association with their hosts. The major goal of this 2-year project is to characterize the bacterial community living inside the lice, and distinguish between lineages of bacteria that live more-or-less permanently inside the lice versus those that are mere transients passing through the louse's digestive tract. This research will require careful examination and comparison of both intra-louse and extra-louse (gopher-associated and free-living) bacterial communities; hence, an important byproduct of this research will be characterization of the microbial communities associated with the entire pocket gopher burrow system. The experimental approach will incorporate three lines of evidence: microscopic visualization of microbial communities inside the lice, culturing and DNA sequencing of bacterial lineages, and culture-independent molecular analyses of bacterial diversity. Ultimately, documentation of a long-term association between the bacteria and their hosts will allow for comparison of rates of genetic change in these two distantly related groups.