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I TAKAHASHI

Publications and source records attributed to I TAKAHASHI.

At least 19 recordsLinked to original sources
PubMed1965

TRANSDUCTION OF SPOROGENESIS IN BACILLUS SUBTILIS.

Takahashi, I. (McMaster University, Hamilton, Ontario, Canada). Transduction of sporogenesis in Bacillus subtilis. J. Bacteriol. 89:294-298. 1965.-A number of asporogenous mutants of Bacillus subtilis were isolated and genetic analyses with these mutants were carried out by means of transduction mediated by bacteriophage PBS 1. The ability to form spores could be restored by transduction in all mutants examined, with the exception of Sp(-)H12-3, although they were not transformable under my experimental conditions. The results of reciprocal transduction suggest that genetic loci at which a mutation can affect sporulation are numerous. A spore marker (sp 1) was transduced jointly with prototrophy and some antibiotic resistance markers (streptomycin, erythromycin, and neomycin). Other spore markers (sp N2-2, sp 170-2, and sp H12-4) were also linked to auxotrophic markers (ser, tyr, and phe) at a fairly high frequency. This linkage relationship indicates that genes controlling the formation of spores are located along the chromosome far apart from each other. The result also suggests that blocks in a variety of biochemical processes may result in the expression of the asporogenous phenotype.

Bacillus subtilis↗
PubMed1965

LOCALIZATION OF SPORE MARKERS ON THE CHROMOSOME OF BACILLUS SUBTILIS.

Takahashi, I. (McMaster University, Hamilton, Ontario, Canada). Localization of spore markers on the chromosome of Bacillus subtilis. J. Bacteriol. 89:1065-1067. 1965.-Attempts were made to locate spore markers on the chromosome by determining the mapping distance of ery(r), str(r), phe, tyr, and ser markers to which the spore markers are closely linked. The results obtained indicated that locus sp N2-2 is located near the terminus and loci sp 170-2, sp H12-4, and sp 1 are distributed between the middle and the origin of the chromosome. These spore markers are not linked to each other. The above observation confirms our previous finding that in Bacillus subtilis spore markers are distributed randomly along the chromosome.

Bacillus subtilis↗
PubMed1964

INCORPORATION OF BACTERIOPHAGE GENOME BY SPORES OF BACILLUS SUBTILIS.

Takahashi, I. (Microbiology Research Institute, Ottawa, Ontario, Canada). Incorporation of bacteriophage genome by spores of Bacillus subtilis. J. Bacteriol. 87:1499-1502. 1964-The buoyant density in a CsCl gradient of deoxyribonucleic acid (DNA) extracted from spores of Bacillus subtilis was found to be identical to that of DNA from vegetative cells. Density-gradient centrifugation of DNA of spores derived from cultures infected with phage PBS 1 revealed the presence of a minor band whose density corresponded to that of the phage DNA in addition to the spore DNA. No intermediate bands were present. The relative amount of the phage DNA present in the spores was estimated to be 11%, suggesting that spores of this organism may incorporate several copies of the phage genome. Although the possibility that true lysogeny may occur cannot be entirely eliminated, the results seem to indicate that the phage genomes incorporated into spores are not attached to the host chromosome in this system.

Bacillus subtilis↗
PubMed1964

[CECOPLICATION].

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Cecal Diseases↗