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Volume 33, Issue 12
Displaying 1-5 of 5 articles from this issue
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Michio TSUKAMURA, Yo NODA, Masakuni YAMAMOTO, Mitsuo HAYASHI1958 Volume 33 Issue 12 Pages 379-388
Published: 1958
Released on J-STAGE: November 30, 2007
JOURNAL FREE ACCESSThe streptomycin-resistance of M. tuberculosis var. hominis has been studied from genetic aspect, and the following conclusions have been obtained.
The streptomycin-susceptibility of this organism is concerned with three genotypes, sensitivity, lower resistance, and higher resistance. The genotype, for lower resistance consists of multiple factors and produces such mutants as giving various sizes of colonies on the medium containing lower streptomycin concentrations but only small colonies on the medium containing higher drug concentrations. The genotype for higher resistance probably consists of a single gene and produces such mutants as giving large colonies even on the medium containing higher drug concentrations. Mutation to these two genotypes for streptomycin-resistance occurs independently. The system of genetic control for streptomycin-resistance in M. tuberculosis var. hominis appears to be similar to that in Escherichia coli in spite of the difference of bacterial species.
Fluctuation of phenotype in the existence of the same genotype exists also in bacteria.View full abstractDownload PDF (546K) -
Taro FUJII, Seiji MATSUMURA1958 Volume 33 Issue 12 Pages 389-397
Published: 1958
Released on J-STAGE: November 30, 2007
JOURNAL FREE ACCESSDownload PDF (2047K) -
Kodo MAEKI1958 Volume 33 Issue 12 Pages 398-404
Published: 1958
Released on J-STAGE: November 30, 2007
JOURNAL FREE ACCESSThe chromosomes of the cabbage butterfly, Pieris rapae, have been studied by several investigators with defferent results: Beliajeff ('30) reported n, 25 for Russian forms, Federley ('38) gave n, 26 for Finnish forms, Lorkovié ('41) informed n, 25 for Yugoslavian forms, and the present author ('53) found n, 26 for apanese forms. It is interesting to know that the chromosomes of Pieris rapae reported by Federley ('38) and by the present author ('53) differ slightly, either in number or in morphology, from those of Russian and Yugoslavian forms studied by Beliajeff and Lorkovic.
Morphologically Pieris rapae from Europe is very closely related to Pieris rapae from Japan. Recently some Japanese lepidopterists have reported the occurrence of Pieris mannii in Shikoku, while most authors are doubtful for its occurrence. The present author was undertaken re-examination of the chromosomes of P. rapae based on the material collected in various localities, with particular reference to the question as to the occurrence of P. mannii in Shikoku. For investigation, the testes of P. rapae were adopted as material; they were presented by mature imagoes of 235 specimens which were collected in the following districts: Shikoku (Kôchi, Kubokawa, Uwajima, Matsuyama, Niihama, Takamatsu), Honshu (Nishinomiya, Osaka) and Hokkaido (Hakodate, Sapporo, Asahigawa).
It was found that there occurs a chromosomal dimorphism in Pieris rapae: there are two groups of animals, one having n, 26 and the other n, 25. The presence of a m-chromosome seems to cause the dimorphism as mentioned above: the individuals having n, 26 contain a m-chromosome in the haploid set, while those of n, 25 carry no such element. The n, 26 individuals are rather frequent in occurrence with a frequency of 65%. It seems most likely that the n, 26 individuals are of an ancestral type, and that the n, 25 individuals are derived form the former as a result of the disappearance of the m-chromosome.
Considered from the results of the chromosome study of P. rapae, it is difficult to discuss the occurrence of P. mannii in Shikoku.View full abstractDownload PDF (1117K) -
V. Germination of F3 seed and the number of somatic chromosomes and external characteristics of F3 plantsGoichi NAKAJIMA1958 Volume 33 Issue 12 Pages 405-411
Published: 1958
Released on J-STAGE: November 30, 2007
JOURNAL FREE ACCESS1. In the present research, the germination of F3 seed, and the number of somatic chromosomes, external characteristics and fertility of F3 plants of Triticum-Secale triple hybrid raised between F1 T. turgidum×S. cereale and T. vulgare were studied.
2. 736 grains of F3 seed were obtained from 21 fertile individuals among 40 F2 plants, and 674 grains of them were sown in separate pots in October 1938 and 1939, and 177 F3 individuals were obtained (Table 1). The fertility of the F3 varies with the each parent, and the percentage of the F3 seed has been shown to vary from 2.50 to 65.37. As a whole, the percentage of the number of F3 seed obtained from the F2 plants having 2n=29-31 or 45 chromosomes showed a rather high percentage in germination.
3. As seen in Table 2, the number of somatic chromosomes of the 177 F3 hybrids varies from 28 to 49. These individuals may be divided into three groups. The F3 individuals raised from F2 having 2n=29-33 chromosomes have 2n=28-32, and these seem to make a group, and most of them have 28-29 chromosomes (71.43% in this group). The number of chromosomes of other F3 individuals raised from F2 having 2n=43-47 chromosomes varies from 2n=40 to 49, and they make another group. The rest of the F3 raised from F2 having 2n=37-39 have 2n=32-43, making a group lying between the above two groups.
4. The external characteristics were observed with 153 individuals of the 177 F3 plants. The length of culms and awns, spikelet number on a spike and spikelet density of F3 individuals having smaller number of chromosomes (2n=28-32) surpass the other F3 plants having the larger number of chromosomes, while, on the length of spikes, the former individuals were inferior to the latter.
5. 126 individuals among the 153 triple F3 plants were somehow fertile. And the fertility per spikelet has shown to vary from 4.2 to 128.0% according to individuals (Table 3). Generally speaking, the percentage of seed fertility per spikelet has been higher in F3 plants having smaller number of chromosomes (28-29). and as the somatic chromosomes increase above these numbers the fertility falls gradually but again rises.View full abstractDownload PDF (1120K) -
1. The life-cycle of the Mycobacterium 607Tadashi HIRANO1958 Volume 33 Issue 12 Pages 412-417
Published: 1958
Released on J-STAGE: November 30, 2007
JOURNAL FREE ACCESSIn the present study the author observed the life-cycle of Mycobacterium 607, morphologically, in vitro, by the phase-contrast microscope.
The vegetative cells which have been cultured on the 3 per cent glycerine-agar culture-medium usually reproduce by the binary fissions.
Sometimes they show small club-like bodies which grow and change into usual bacteria.
The cells which have been cultured for fifteen days on Oka-katakura's culture-medium form spherical bodies, rod bodies and germinating processes in the case of the old culture, the cells become granular form.
The author suppose that, in the life-cycle of Mycobacterium 607, the spherical body, at first, divides into Diplococcus-like forms which change into rod bodies. The rod bodies reproduce by the binary fission in some cases and also show the small club-like bodies.
When the nutrition is adepuate, the cell reproduces by the binary fission and takes the ordinary form. If nutrient medium is not adequate, the cell takes degenerative form and changes into rod body which becomes the spherical form. The spherical body become into granular forms which are thought to be the resting cells.
Though the spherical and granular forms of Mycobacteria has been thought to be the degenerative forms, the present author thinks that the spherical form is one stage of the life-cycle because the cell division is quite normal when the spherical body divides into Diplococcus-like forms.
The polymorphic forms of Mycobacterium 607 are seen as in the case of the other Mycobacteria.
The present author thinks that the polymorphic forms are the stages of the life-cycle, respectively.View full abstractDownload PDF (710K)
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