GLOBAL REGULATION OF VIRULENCE FACTOR IN BORDETELLA PERTUSSIS

我们实验室的主要工作重点一直是病毒的轨迹 百日咳杆菌。该基因座负责调节B。 百日咳毒力决定因素(百日咳毒素、丝状 血凝素等)对环境刺激的反应。这个轨迹是 还有一个可逆性移码突变的位置，它导致 相变现象。在过去，我们观察到两个 与百日咳杆菌密切相关的菌株在 截然不同的利率。我们最近扩展了这一观察结果 通过在卡那霉素抗性中构建明确的移码突变 基因，并表明这种突变的逆转也发生在 在这两个菌株中的比率截然不同。我们目前正在 参与了这种超可变表型的遗传图谱，具有 眼部基因的分离(S)负责。此映射已完成 这是可能的，因为我们最近完成了B的物理地图。 百日咳染色体。先前分离的基因的物理图谱是 一项简单而直接的任务，我们有几个协作 与该领域的其他工作人员一起绘制特定的基因图谱。然而， 这一图谱的推导也允许使用遗传工具进行图谱绘制。 具体地说，我们设计和构建了新的菌株和新的 载体允许我们使用类似HFR的菌株来进行基因图谱绘制 百日咳。这样的方法将允许隔离一些 使用标准克隆无法实现的有趣基因 技巧。染色体图谱的主要科学发现是 百日咳杆菌毒力决定因素的基因是不连锁的，即 分散在染色体上。这一发现的含义是 目前正在通过构建其他菌株的图谱进行扩展。 百日咳和其他波尔德氏菌的种类，希望进一步 定义了它们的进化关系。

The primary focus of work in our laboratory has been the vir locus of Bordetella pertussis. This locus is responsible for the regulation of B. pertussis virulence determinants (pertussis toxin, filamentous hemagglutinin, etc.) in response to environmental stimuli. This locus is also the site of a reversible frameshift mutation which results in the phenomenon of phase variation. In the past we had observed that two closely related strains of B. pertussis underwent phase variation at dramatically different rates. We have recently extended this observation by constructing a defined frameshift mutation in a kanamycin resistance gene and showing that the reversion of this mutation also occurs at dramatically different rates in these two strains. We are currently engaged in the genetic mapping of this hypermutable phenotype, with an eye to the isolation of the gene(s) responsible. This mapping is made possible because we have recently completed a physical map of the B. pertussis chromosome. Physical mapping of previously isolated genes is a simple and straightforward task, and we have several collaborations with other workers in the field to map specific genes. However, the derivation of this map also allows the use of genetic tools for mapping. Specifically, we have designed and constructed new strains and new vectors which allow us to do genetic mapping using Hfr-like strains of B. pertussis. Such an approach will allow the isolation of some interesting genes which has not been possible using standard cloning techniques. The primary scientific finding of the chromosomal map was that the genes for B. pertussis virulence determinants are unlinked, i.e. are scattered around the chromosome. The implications of this finding are currently being extended by constructing maps of other strains of B. pertussis and other species of Bordetella with the hopes of further defining their evolutionary relationships.