TN3 TRANSPOSITION IMMUNITY: A NEW GENETIC PHENOMENON

TN3 转座免疫：一种新的遗传现象

• 批准号: 3130856
• 负责人: FRED L HEFFRON
• 金额: $ 12.33万
• 依托单位: SCRIPPS CLINIC AND RESEARCH FOUNDATION
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-03-01 至 1987-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3130856
• 关键词: Escherichia coli; R factors; bacterial genetics; beta lactamase; chromosome deletion; chromosome inversion; chromosome translocation; gene expression; gene redundancy; genetic manipulation; molecular cloning; nuclease; nucleic acid chemical synthesis; nucleic acid sequence; nucleic acid structure

Transposition immunity is a relatively unstudied genetic phenomenon in bacteria. Tn3 transposition immunity is a cis acting mechanism which limits Tn3 insertion into a plasmid. We have shown that Tn3's terminal repeat can confer immunity to a plasmid. However, we also find that the transposition immunity phenotype can be affected by host sequences. During this granting period we will pursue a genetic approach, using techniques of in vitro and in vivo mutagenesis, to dissect the immunity sequence as well as host and plasmid sequences which also affect immunity. We will determine whether other transposons related to Tn3 show immunity and if so determine whether they show cross immunity to each other. We will determine to how large a DNA molecule Tn3 can confer immunity and whether there are other parameters which also affect immunity. For example, some naturally occurring plasmids are immune to Tn3 though they do not confer penicillin resistance. Through this genetic approach, as well as additional experiments, we will distinguish between the various models for how transposition immunity works.

转座免疫是一种相对未被研究的遗传现象 细菌。 Tn3 转座免疫是一种顺式作用机制，限制 Tn3 插入质粒。 我们已经证明 Tn3 的末端重复可以 赋予质粒免疫力。 然而我们也发现，转置 免疫表型可能受到宿主序列的影响。 本次授予期间 在此期间，我们将采用体外和体外技术，采用遗传方法 体内诱变，剖析免疫序列以及宿主和 质粒序列也影响免疫力。 我们将确定是否 与 Tn3 相关的其他转座子表现出免疫力，如果是这样，确定是否 它们彼此表现出交叉免疫力。 我们将确定有多大 DNA分子Tn3能否赋予免疫力以及是否还有其他参数 也会影响免疫力。 例如，一些天然存在的质粒 尽管它们不赋予青霉素耐药性，但对 Tn3 免疫。 通过 这种遗传方法以及其他实验，我们将 区分转座免疫如何发挥作用的各种模型。