Abstract
A series of clear mutants of the temperate phage 16–3 of Rhizobium meliloti were isolated that included various point and deletion mutants of the C cistron, coding for the phage repressor. It was observed that recombinant genotypes, such as c+ and ti (temperature-sensitive allele), which form turbid plaques, can be detected quantitatively as lysogenic colonies and scored even at frequencies as low as 10-6. Point mutations, deletions and the autonomy of intracistronic second-site mutations were characterized by this method. Further analysis has shown that each possible pair from three ti mutants gave nonconditional clear recombinants. It was shown that these latter bear the two initial ti mutations, suggesting a cumulative effect of two conditional mutations on the structure of the repressor protein. The double mutants were utilized in fine-structure mapping of the C cistron.
Full Text
The Full Text of this article is available as a PDF (652.9 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Dallmann G., Orosz L., Sain B. Restriction mapping of DNA of temperate Rhizobium meliloti phage 16-3: comparison of genetic and physical maps indicates a long, genetically silent chromosomal arm. Mol Gen Genet. 1979 Nov;176(3):439–448. doi: 10.1007/BF00333109. [DOI] [PubMed] [Google Scholar]
- ORDOGH F., SZENDE K. Temperate bacteriophages isolated from Rhizobium meliloti. Acta Microbiol Acad Sci Hung. 1961;8:65–71. [PubMed] [Google Scholar]
- Orosz L., Rostás K., Hotchkiss R. D. A comparison of two-point, three-point and deletion mapping in the C cistron of rhizobiophage 16-3, with an explanation for the recombination pattern. Genetics. 1980 Feb;94(2):249–263. doi: 10.1093/genetics/94.2.249. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Orosz L., Sik T. Genetic mapping of rhizobiophage 16-3. Acta Microbiol Acad Sci Hung. 1970;17(2):185–194. [PubMed] [Google Scholar]
- Orosz L., Sváb Z., Kondorosi A., Sik T. Genetic studies on rhizobiophage 16-3. I. Genes and functions on the chromosome. Mol Gen Genet. 1973 Sep 27;125(4):341–350. [PubMed] [Google Scholar]