Rastogi Rajat, Wu Martin, Dasgupta Indrani, Fox George E
Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA.
BMC Microbiol. 2009 Sep 25;9:208. doi: 10.1186/1471-2180-9-208.
Results of microbial ecology studies using 16S rRNA sequence information can be deceiving due to differences in rRNA operon copy number and genome size of the detected organisms. It therefore will be useful for investigators to have a better understanding of how these two parameters differ in various organism types. In this study, the number of ribosomal operons and genome size were separately mapped onto a Bacterial phylogenetic tree.
A representative Bacterial tree was constructed using 31 marker genes found in 578 bacterial genome sequences. Organism names are displayed on the trees using graduations of color such that similar colors indicate similar numbers of operons or genome size. The resulting images provide an intuitive understanding of how copy number and genome size vary in different Bacterial phyla.
Once the phylogenetic position of a novel organism is known the number of rRNA operons, and to a lesser extent the genome size, can be estimated by examination of the colored maps. Further detail can then be obtained for members of relevant taxa from the rrnDB database.
由于所检测生物的rRNA操纵子拷贝数和基因组大小存在差异，利用16S rRNA序列信息进行的微生物生态学研究结果可能具有误导性。因此，研究人员更好地了解这两个参数在不同生物类型中的差异将很有帮助。在本研究中，核糖体操纵子数量和基因组大小被分别映射到一棵细菌系统发育树上。
利用在578个细菌基因组序列中发现的31个标记基因构建了一棵代表性的细菌树。生物名称以颜色渐变的方式显示在树上，使得相似颜色表示相似的操纵子数量或基因组大小。所得图像直观地展示了不同细菌门中拷贝数和基因组大小是如何变化的。
一旦知道了新生物的系统发育位置，就可以通过查看彩色图谱估计rRNA操纵子的数量，在较小程度上还可以估计基因组大小。然后可以从rrnDB数据库中获取相关分类群成员的更多详细信息。
