...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of bacteriology >The ner Gene of Photorhabdus: Effects on Primary-Form-Specific Phenotypes and Outer Membrane Protein Composition
【24h】

The ner Gene of Photorhabdus: Effects on Primary-Form-Specific Phenotypes and Outer Membrane Protein Composition

机译：Photorhabdus的内在基因：对初级形式特定的表型和外膜蛋白组成的影响。

获取原文
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The nematode-bacterium complex of Heterorhabditis-Photorhabdus is pathogenic to insect larvae. The bacteria undergo a form of phenotypic switching whereby the primary form, at the stationary phase of the growth cycle, makes a range of products and has the capacity to support nematode growth, whereas the secondary form does not express these phenotypes. The work described here investigated the mechanism regulating phenotypic variation by transforming the primary cells with secondary-form DNA on a low-copy-number vector and screening for colonies which did not produce the yellow pigment characteristic of primaries. Four transformants all carrying the same gene were found to loose primary-form-specific characteristics, and the gene was sequenced and identified as ner, a regulatory gene in gram-negative bacteria and their phages. Unexpectedly, inactivation of the endogenous gene in the secondaries did not cause them to revert to the primary phenotype, and the gene was expressed in the primary form as well as the secondary form during exponential but not stationary phase and deregulated in the plasmid-bearing primary form. These and other pieces of evidence indicate that the endogenous ner gene is not responsible for the secondary phenotype, but that ner, when overexpressed, can repress expression of primary phenotypes at stationary phase. Inactivation of the endogenous ner gene in the primary form affected the outer membrane protein profile. A number of outer membrane proteins displayed differential accumulation in the primary and secondary forms at stationary phase, and two of the primary-form-specific proteins were absent from the ner primary strain.
机译：幽门螺杆菌-光梭菌的线虫-细菌复合体对昆虫幼虫具有致病性。细菌经历表型转换的形式，由此初级形式在生长周期的固定阶段产生一系列产品，并具有支持线虫生长的能力，而次级形式则不表达这些表型。本文所述的工作研究了通过在低拷贝数载体上用次级形式的DNA转化原代细胞并筛选不产生原代黄色色素特征的菌落来调节表型变异的机制。发现四个都携带相同基因的转化子失去了初级形式特异的特性，并对该基因进行了测序并鉴定为革兰氏阴性细菌及其噬菌体的调控基因 ner 。出乎意料的是，二级中的内源基因失活不会导致它们恢复为一级表型，并且该基因在一级和二级中均以指数形式表达，但在指数期但不是固定期表达，并且在携带质粒的一级中失调形成。这些证据和其他证据表明，内源性 ner 基因与次级表型无关，但 ner 过度表达时，可以在稳定期抑制初级表型的表达。 。初级形式的内源性 ner 基因的失活影响了外膜蛋白的分布。许多外膜蛋白在固定相中以初级和次级形式表现出不同的积累， ner 初级菌株中缺少两种初级形式特异性蛋白。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号