RUI: Molecular Systematics of the Conifers: Chloroplast DNA Structural Evidence

[00:75 . 700]松柏：松果植物或针叶树，包括松树、冷杉、杜松、柏树及其亲戚，现存的植物有几百种，分60个左右属，是中生代统治陆地环境的进化谱系中幸存的成员尽管许多代表性分类群的基因序列数据正在积累，但这些幸存群体之间的系谱关系尚未牢固建立。琳达·劳布森博士正在贡献新的结构基因组数据，以帮助回答有关针叶树系统发育关系的问题。特别是，她正在研究大约20个针叶树属样本的叶绿体基因组中基因的含量和顺序，包括可能相关的银杏和遗传植物。叶绿体基因组突变的精细限制酶图谱将揭示基因顺序（倒置或易位）和基因丢失或复制的变化，其中一些已经在她的实验室中得到了表征。这些结构突变大多是罕见的，并且可能标记出系统发育相关的属群，从而为分类学和分类研究提供了新的证据。叶绿体基因组图谱，反过来，将通过基因测序或更精细的限制酶图谱，帮助更详细地研究在分类学上有问题的群体中物种水平的关系。在整个项目中，与Raubeson博士过去的工作一样，本科生将参加旨在为他们提供现代分子系统发育方法培训以及设计和执行研究活动经验的离散活动。

0075700Raubeson The cone-bearing plants or conifers, including pines, firs, junipers, cypresses, and relatives, number in the several hundred species of living plants, disposed in 60 or so genera, and are the surviving members of an evolutionary lineage that dominated terrestrial environments in the Mesozoic. Genealogical relationships among these surviving groups are not yet firmly established, although gene sequence data are accumulating for many representative taxa. Dr. Linda Raubeson is contributing new structural genomic data to help answer questions about the phylogenetic relationships of conifers. In particular, she is studying the content and order of genes in the chloroplast genome of a sample of 20 or so genera of conifers, and including the likely related ginkgo and gnetophytes. Fine-scale restriction-enzyme mapping of mutations along the chloroplast genome will reveal changes in gene order (inversions or translocations) and gene losses or duplications, some of which have already been characterized in her laboratory. Most of these structural mutations are of rare occurrence, and are likely to mark groups of phylogenetically related genera, thus providing new evidence for taxonomic and classification studies. The chloroplast genome maps, in turn, will aid more detailed studies of species-level relationships in taxonomically problematic groups, either by gene sequencing or yet finer scale restriction-enzyme mapping. Throughout the project, as in past work by Dr. Raubeson, undergraduate students will participate in discrete activities targeted to provide them training in modern molecular phylogenetic methods and experience in the design and execution of a research activity.