Nejvíce citovaný článek - PubMed ID 5445780
The study of mutagnesis in Mycobacterium phlei
This review summarizes the main results obtained in the fields of general and molecular microbiology and microbial genetics at the Institute of Microbiology of the Academy of Sciences of the Czech Republic (AS CR) [formerly Czechoslovak Academy of Sciences (CAS)] over more than 50 years. Contribution of the founder of the Institute, academician Ivan Málek, to the introduction of these topics into the scientific program of the Institute of Microbiology and to further development of these studies is also included.
- MeSH
- akademie a ústavy dějiny MeSH
- dějiny 20. století MeSH
- mikrobiální genetika dějiny MeSH
- molekulární biologie dějiny MeSH
- Check Tag
- dějiny 20. století MeSH
- Publikační typ
- časopisecké články MeSH
- historické články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Geografické názvy
- Česká republika MeSH
Gene manipulation in mycobacteria developed in two phases. In the first phase genes of mycobacteria were transferred into cells of E. coli and Streptomyces lividans. In the second phase, heterologous genes were transferred into mycobacteria either with a shuttle plasmid or hybrid plasmids. A prerequisite for successful gene manipulation in mycobacteria was a thorough understanding of plasmids in mycobacteria. Construction of recombinant DNA molecules contributed not only to the fact that mycobacteria did not remain outside the mainstream of modern genetic research but also to their present practical importance.
Mutant strains of Mycobacterium sp. V-649 producing highly mucous colonies on a solid cultivation medium were prepared after treatment with N-methyl-N'-nitro-N-nitrosoguanidine and production of the exocellular polysaccharide was tested. The strains were cultivated in media with suitable sugar sources under submerged conditions. It was found that Mycobacterium sp. V-649/15 produces a maximum of 15-19% polymer after a 5-6-d cultivation. Gas chromatography indicated that the exocellular polysaccharide produced by this strain is of glucan type.
It is generally assumed that genetic research of mycobacteria is delayed as compared with other, more commonly used, bacterial models, particularly in the field of genetic transfers. In the field of mutagenesis the problems have been studied to such an extent that replication maps of the chromosome of M. phlei and M. tuberculosis H37 Rv have already been constructed and a new model of the cell cycle of bacteria exhibiting a slow growth rate has been worked out. When the problems of mycobacterial genetics are looked upon in the light of gene manipulations it may be concluded that mycobacteria belong to a few models whose genes are used for cloning and that problems of practical significance will be studied by means of the most modern approaches.
- MeSH
- mikrobiální genetika * MeSH
- Mycobacterium genetika MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- MeSH
- histidin metabolismus MeSH
- kultivační média MeSH
- methylnitronitrosoguanidin farmakologie MeSH
- mutace * MeSH
- Mycobacterium účinky léků genetika metabolismus MeSH
- vankomycin * farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- histidin MeSH
- kultivační média MeSH
- methylnitronitrosoguanidin MeSH
- vankomycin * MeSH
N-Methyl-N-nitrosourea was used to induce auxotrophic, scotochromogenic and isonicotinic acid hydrazide resistant mutants in Mycobacterium phlei and its effect was compared with that of nitrosoguanidine. Seventeen auxotrophic mutants requiring amino acids or vitamins and 52 scotochromogenic mutants with orange colonies were induced. The frequency of isonicotinic acid hydrazide-resistant mutants increased by two orders of magnitude.
- MeSH
- aminokyseliny metabolismus MeSH
- antibiotická rezistence MeSH
- biologické pigmenty biosyntéza MeSH
- isoniazid farmakologie MeSH
- methylnitrosomočovina farmakologie MeSH
- mutace * MeSH
- Mycobacterium phlei genetika fyziologie MeSH
- Mycobacterium genetika MeSH
- nitrosoguanidiny farmakologie MeSH
- nitrosomočovinové sloučeniny farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- aminokyseliny MeSH
- biologické pigmenty MeSH
- isoniazid MeSH
- methylnitrosomočovina MeSH
- nitrosoguanidiny MeSH
- nitrosomočovinové sloučeniny MeSH
New facts about the replication map of Mycobacterium phlei chromosome are summarized. Replication positions of two genes located in marginal regions of the replication map, ile close to the origin and ser near the terminus, were determined. Known positions of replication of some genes were defined with more precision within 2.5--5-min intervals using the method of sequential mutagenesis in synchronized cultures (leu, met, bac, pyr, stm, tet, cyc, his). Replication positions of genes responsible for the biosynthesis of thiamine and resistance to tetracycline and vancomycin were further identified. The contemporary replication map contains replication positions of 24 genes.
The aim of the present work was to construct a replication map of the chromosome of Mycobacterium phlei. The method of mutagenesis of the replication point by means of nitrosoguanidine was applied to synchronously multiplying populations. Back mutations and forward mutations were induced in auxotrophic mutants PA met and PA leu as well as in double auxotrophic mutants with methionine as the reference marker and the following order of replication of eleven genes on the chromosome was thus established: leu-Eth, Res-Stm, Cyk-pur-met, arg, Cyk-Bac-inl.
- MeSH
- antibiotická rezistence MeSH
- buněčné dělení MeSH
- DNA bakterií biosyntéza MeSH
- geny MeSH
- leucin biosyntéza MeSH
- mapování chromozomů * metody MeSH
- methionin biosyntéza MeSH
- methylnitronitrosoguanidin MeSH
- mutace MeSH
- mutageny MeSH
- Mycobacterium phlei * účinky léků růst a vývoj metabolismus MeSH
- Mycobacterium * MeSH
- replikace DNA MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- DNA bakterií MeSH
- leucin MeSH
- methionin MeSH
- methylnitronitrosoguanidin MeSH
- mutageny MeSH
Results obtained when studying conjugation in mycobacteria by means of different methods are summarized. The method of conjugation on surface of a solid complete medium was tested with different auxotrophic mutants of different strains of Mycobacterium smegmatis. It was not possible to obtain positive results even by means of the above method. This was probably due to unsuitability of the chosen strains of Mycobacterium smegmatis. Preparation of the donor strain by transfer of the F factor from Escherichia coli F'ORF 1 ade+ lac+ pro+ to Mycobacterium phlei PA ade Stmr by means of sexduction is described. Frequency of the phenotype PA ade+ Stmr increased in the average by two and a half orders of magnitude with respect to the control, however, a further transfer from cultures of the cells ade+ Stmr to cells ade could not be demonstrated. Experiments aimed at transferring the R factor from strains Escherichia coli K-12 to Mycobacterium phlei were unsuccessful.
- MeSH
- Escherichia coli MeSH
- F faktor MeSH
- konjugace genetická * MeSH
- kultivační média MeSH
- methylnitronitrosoguanidin MeSH
- mutace MeSH
- mutageny MeSH
- Mycobacterium phlei růst a vývoj MeSH
- Mycobacterium * růst a vývoj metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- kultivační média MeSH
- methylnitronitrosoguanidin MeSH
- mutageny MeSH
- MeSH
- časové faktory MeSH
- koncentrace vodíkových iontů MeSH
- leucin metabolismus MeSH
- methionin metabolismus MeSH
- mutace * MeSH
- mutageny * MeSH
- Mycobacterium účinky léků růst a vývoj metabolismus MeSH
- nitrosoguanidiny farmakologie MeSH
- nízká teplota MeSH
- pufry MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- leucin MeSH
- methionin MeSH
- mutageny * MeSH
- nitrosoguanidiny MeSH
- pufry MeSH
