...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Rearrangements in the genome of the bacterium Salmonella typhi.
【24h】

Rearrangements in the genome of the bacterium Salmonella typhi.

机译：伤寒沙门氏菌基因组中的重排。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We have determined the genomic map of the bacterium Salmonella typhi Ty2, the causal organism of typhoid fever, by using pulsed-field gel electrophoresis. Digestion of the Ty2 genome with endonucleases Xba I, Bln I, and Ceu I yielded 33, 26, and 7 fragments, respectively, that were placed in order on a circular chromosome of 4780 kb. Transposon Tn10 was inserted in specific genes of Salmonella typhimurium and transduced into S. typhi, and thus, the positions of 37 S. typhi genes were located through the Xba I and Bln I sites of the Tn10. Gene order on chromosomes of Escherichia coli K-12 and S. typhimurium LT2 is remarkably conserved; however, the gene order in S. typhi Ty2 is different, suggesting it has undergone major genomic rearrangements during its evolution. These rearrangements include inversions and transpositions in the 7 DNA fragments between the seven rrn operons for rRNA (postulated to be due to homologous recombination in these rrn genes), another inversion that covers the replication terminus region (resembling inversions found in other enteric bacteria), and at least three insertions, one as large as 118 kb. Partial digestion of genomic DNA with the intron-encoded endonuclease I-Ceu I, which cuts only in rrn genes, shows chromosomal rearrangements, apparently due to homologous recombination in the rrn genes, that were detected in all wild-type strains of S. typhi tested. These rearrangements may have been selected to compensate for the insertions that otherwise would have altered the locations of genes with respect to the origin and terminus of replication. These observations are relevant to our view of the evolution of the bacterial genome and may be significant in the virulence of S. typhi.
机译：我们已经通过使用脉冲场凝胶电泳确定了伤寒沙门氏菌Tal2细菌的基因组图谱。用核酸内切酶Xba I，Bln I和Ceu I消化Ty2基因组分别产生33、26和7个片段，这些片段顺序排列在4780 kb的环形染色体上。将转座子Tn10插入鼠伤寒沙门氏菌的特定基因中并转导到伤寒沙门氏菌中，因此，通过Tn10的Xba I和Bln I位点定位了37个伤寒沙门氏菌基因的位置。大肠杆菌K-12和鼠伤寒沙门氏菌LT2染色体上的基因顺序非常保守；但是，伤寒沙门氏菌Ty2中的基因顺序不同，这表明它在进化过程中经历了重大的基因组重排。这些重排包括rRNA的7个rrn操纵子之间的7个DNA片段的倒置和转座（假定是由于这些rrn基因中的同源重组引起的），另一个覆盖复制末端区域的倒置（类似于在其他肠道细菌中发现的倒置），至少三个插入，一个最大118 kb。用内含子编码的核酸内切酶I-Ceu I（仅在rrn基因中切割）对基因组DNA进行的部分消化显示染色体重排，这显然是由于rrn基因中的同源重组所致，在所有野生型伤寒沙门氏菌菌株中都检测到了这种重组。经过测试。可以选择这些重排以补偿插入，否则该插入将改变基因相对于复制起点和末端的位置。这些观察结果与我们对细菌基因组进化的看法有关，并且可能在伤寒链球菌的毒性中具有重要意义。

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