The initial replication region of the chromosome on the replication map of M. phlei constructed by means of sequential mutagenesis in synchronous populations was accurately determined. By following the time shift of the replication moment of the genes bac and met in the control culture and in the culture with the initial inhibition of DNA synthesis by nalidixic acid the start of replication of the chromosome was determined at 15 min before replication of the gene ile. On the basis of the results obtained a scheme of the cell cycle in M. phlei was proposed. Intervals C and D depend on the generation time, become prolonged independently of each other and assume the whole cycle. The ratio C/(C + D) equals to 0.56 and the interval D has a value of 0.76 of the interval C. The mutual ratio of the intervals C : D is 1.3 : 1.0. The obtained results make it possible to form the assumption about mutual ratios between the chromosome replication and cell division in bacteria exhibiting slow growth rates.

• MeSH
• bakteriální chromozomy MeSH
• buněčný cyklus MeSH
• časové faktory MeSH
• DNA bakterií biosyntéza   MeSH
• Escherichia coli cytologie   MeSH
• kyselina nalidixová farmakologie   MeSH
• Mycobacterium phlei cytologie   genetika   MeSH
• Mycobacterium cytologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA bakterií MeSH
• kyselina nalidixová 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

It was the aim of the present work to construct the replication map of the chromosome of Mycobacterium phlei. The method of mutagenesis of the replication point by N-methyl-N-nitroso-N'-nitroguanidine in synchronously dividing populations and the method of analysis of gene frequency were applied. The order of replication of 19 genes on the chromosome was determined by means of induction of back mutations and forward mutations in auxotrophic mutants PA leu and PA met and in double auxotrophic mutants with methionine as a reference marker.

• MeSH
• bakteriální chromozomy metabolismus   MeSH
• geny * MeSH
• mapování chromozomů MeSH
• mutace MeSH
• Mycobacterium phlei genetika   metabolismus   ultrastruktura   MeSH
• Mycobacterium genetika   MeSH
• Publikační typ
• časopisecké články MeSH

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

• 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