Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 18 , Issue 1
Showing 1-9 articles out of 9 articles from the selected issue
  • II. Factors affecting the Feulgen reaction in vitro
    Atuhiro Sibatani
    1953 Volume 18 Issue 1 Pages 1-12
    Published: May 30, 1953
    Released: March 19, 2009
    1. Large excess of Schiff reagent enhances the color development of the Feulgen reaction in vitro, but this is rather due to the excess of metabisulfite contained in the reagent. The course of the color development is considerably influenced by the composition of the reaction mixture.
    2. On the basis of these findings, a standard procedure of the reaction was proposed. This employs 0.1M glycine buffer of pH 2.28 fortified with excess metabisulfite as the medium; then, the volume of the Schiff reagent to be added can be reduced down to 5 per cent of the final volume of the reaction mixture without affecting the sensitivity of the reagent.
    3. The attainable maximum of the color intensity is conditioned by the method of hydrolysis; N HCl at 60° gives higher values than glycine buffers of pH 1.42 or 2.28 at 100° The observed difference is not necessarily due to the destruction of the potentially reactive group. Hydrolysis for 15-30 minutes with N HCl at 60° gives an extinction value of ca. 0.25 (1cm optical path) per μg DNA-P per ml of the final mixture prepared in accordance with the standard procedure, after standing for 3-4 hours.
    4. The spectral absorption curve of the Feulgen pigment is modified by the conditions of hydrolysis and the temperature and duration of the color development. Its maximum is situated at 546mμ or somewhat longer wavelengths, shifted distinctly towards the shorter wavelengths from that of the Schiff pigment developed with formaldehyde, as far as the both reactions are conducted according to the standard procedure.
    5. Two samples of DNA obtained from beef spleen and herring sperm give fairly identical extinctions per unit quantity of DNA phosphorus.
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  • Genom analysis by means of differential reaction of chromosome segments to low temperature
    Tutomu Haga, Masataka Kurabayashi
    1953 Volume 18 Issue 1 Pages 13-28
    Published: May 30, 1953
    Released: March 19, 2009
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  • Syunsaku Nogusa
    1953 Volume 18 Issue 1 Pages 29-35
    Published: May 30, 1953
    Released: March 19, 2009
    The comparative study of chromosomes in male germ cells of some species of lizards belonging to the Lacertidae were undertaken with the purpose to find, if any, the cytotaxonomic characteristics. Takydromus tachydromoides, and T. smaragdinus show 38 chromosomes in diploid, both having a pair of the m-chromosomes of minute size, while Lacerta vivipara possesses 36 diploid chromosomes containing no m-chromosomes. The m-chromosomes exhibit a size variation by species, or even by individuals: They are exceptionally in size in a specimen of T. smaragdinus, medium sized in the ordinary specimens of the same species, and extremely small in T. tachydromoides. In L. vivipara there are no m-chromosomes. By the evidence of a gradual diminution of the m-chromosomes by species and the assumption of their final disappearance, the numerical relation of chromosomes existing in Takydromus and L. vivipara may be explicable.
    The correlation between the chromosome diminution and the geographical distribution of animals was considered.
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  • Seizi Tatuno, Koji Yano
    1953 Volume 18 Issue 1 Pages 36-42
    Published: May 30, 1953
    Released: March 19, 2009
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  • Goichi Nakajima
    1953 Volume 18 Issue 1 Pages 43-49
    Published: May 30, 1953
    Released: March 19, 2009
    1. In the present investigation, cytological studies on the F1 plants, raised from Triticum sphaerococcum and Secale sereale, was carried out.
    2. 160 flowers on 10 spikes of T. sphaerococcum (n=21) were pollinated with the pollen of S. cereale (n=7), and 46 grains were obtained. From these grains 5 F1 plants were raised. The percentage of the raised indivi-duals to the number of all the pollinated flowers was 3.13 per cent.
    3. The external characters of F1 plants seem to have resemblance to the parents, although much more closely to the mother plant (T. sphaerococcum) than the intermediate of the parents (Photo. 1 and Table 1).
    4. The number of somatic chromosomes of F1 plants counted to be 28 (Fig. 1) and it corresponds to the sum of the reduced chromosome numbers of the parents.
    5. At first maturation division in PMCs of the F1 plants, 04 bivalents and 2820 univalents were observed (Figs. 28). The frequency of bivalents in PMCs was shown in Table 2, and the case of zero in the number of bivalents appeared to be the mode. These bivalents seem to be derived from synthesis between A and B or among A, B and D genomes of T. sphaerococcum which is the mother plant. As there seems to be no homology between A, B, D genomes of T. sphaerococcum and R genome of S. cereale, synthesis will not occur between their chromosomes.
    6. At ana-telophase in heterotypic division of PMCs, the chromosomes were distributed to the opposite poles from 14:14 to 27: 1.
    7. The anther of these F1 plants was not opened and pollen grains showed almost sterile, but on rare occasions, some anthers were opened and consequently a few seed (5 grains) were obtained in natural selfing. From these 5 grains one F2 plant was raised.
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  • Spontaneous breakage and fusion of chromosomes
    Tutomu Haga
    1953 Volume 18 Issue 1 Pages 50-66
    Published: May 30, 1953
    Released: March 19, 2009
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  • II. Veränderung im Ei bei der Befruchtung oder Aktivierung
    Yasuhiko Kanoh
    1953 Volume 18 Issue 1 Pages 67-79
    Published: May 30, 1953
    Released: March 19, 2009
    Um die Befruchtungserscheinung kenntlich zu machen, wurden die Veränderungen im Ei bei der Befruchtung, sowie bei der künstlichen Aktivierung durch Lebendbeobachtung and Schnittbetrachtung des fixierten Materials untersucht.
    Wenn das Ei besamt wird, kommt ein Zerfall der Kortikalalveoli im Eikortex wellenweise am animalen Pol beginnend ringsum vor, dann tritt ein Perivitellinraum in die Erscheinung, und die bipolare Differenzierung beginnt, wobei das Ooplasma alläahlich am animalen sowie am vegetativen Pol sich sammelt. Aber bald danach hört die Sammlung am vegetativen Pol auf, sodaß nur die schon vor der Befruchtung vorhandene schwach ausgeprägte Keimscheibe meter und mehr hervorwächst und sich hochwölbt. Die erste Furchung geschieht 2½ Stunden nach Besamung (Temp. 10°C).
    Das unbefruchtete Reifei ist die Voreizelle, d.h. der Oozyt II. Ordnung, und das Metaphasestadium der IIten Richtungsspindel kann erst nach dem Eindringen des Spermiums in den Eikortex, weiter fortschreiten.
    Mit Ausnahme vom Fehlen des Spermiums ist die Veränderung bei der künstlichen Ei-Aktivierung derjenigen bei der Befruchtung ganz gleich; nämlich, mit Anstich werden die Eier ohne Spermium aktiviert, infolgedessen einerseits das Zerfallen der Kortikalalveoli and die bipolare Differenzierung geschehen, dann die Keimscheibe sich hoch wölbt, andererseits die Teilung der Ilten Richtungsspindel fortschreitet und der Richtungskörper abgeschnürt, danach der weibliche Vorkern hergestellt wird. Anderes gesagt, die Eier ohne Spermium konnen nur mit Anstich ihre Reifungsteilung fertig machen.
    Bei Fischeiern findet in der Regel keine Polyspermie statt, sondern Monospermie. Dies ist auch der Fall beim Heringsei. Nach einigen Diskussionen darüber, wird der Schiuß gezogen, daß die Verhinderung der Polyspermie durch zwei Mchenismen gesichert wird, nämlich durch Verschließen der Mikropyle und durch eine schützende Veränderung im Eikortex nach der Ei-Aktivierung. Über these schützende Veränderung ist ferner eine Erwägung gegeben.
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  • Atuhiro Sibatani, Michio Fukuda
    1953 Volume 18 Issue 1 Pages 80-85
    Published: May 30, 1953
    Released: March 19, 2009
    Mitotic indices of parenchymal cells of rat livers in postnatal growth were calculated under several assumptions from the age and the increase in number of hepatic nuclei estimated by biochemical methods with animals in various growth stages, and compared with those established by microscopic observations on the same materials. As to the general pattern of the change in mitotic index across various growth stages, the calculation proved to agree fairly well with the observation, but the former tends to give considerably lower values. The reason of such a discrepancy is not clear. Low mitotic activity of hepatic cells in adult rats can be regarded as an expression of slow increase in number of hepatic nuclei rather than of cellular turnover of liverr parenchyma.
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  • V. Chromosome numbers of the hybrid sugarcanes bred in Formosa
    Akira Moriya
    1953 Volume 18 Issue 1 Pages 86-92
    Published: May 30, 1953
    Released: March 19, 2009
    1) Chromosome numbers of eleven Formosan sugarcane varieties raised by crossing were determined as follows:
    Varieties Parentage Chromosome
    number (2n)
    F 46 920 POJ×Fm 3 122
    F 107 2878 POJ×2940 POJ 107, 107+1f
    F 108 2725 POJ×F 46 ca. 109
    F 110 2878 POJ×Fm 3 124
    F 118 2878 POJ×F 84 117
    F 122 Badila×EK 28 ca. 130
    F 125 11/9C×2878 POJ ca. 128+2f
    F 133 2725 POJ×S. robustum 94
    11/9C 2725 POJ×Sweet Sorghum 118
    271/11C (2725 POJ×Japanese Broom corn)
    ×F 108 112 or 111+1f
    1614/13A F 108×S. robustum 94
    2) F 122 is a hybrid between two varieties, both having 2n=80. Its chromosome number is much higher than the expected number, presumably because of the abnormal gamete formation of EK 28, although the detailed mechanism is unknown.
    3) Back crosses of sugarcane-sorghum hybrids with sugarcanes showed either nearly the expected chromosome number or ten chromosomes more. The early maturing hybrid was not obtained from the descendants of sugarcane-sorghum hybrids.
    4) Two hybrids between S. robustum and commercial varieties were found to have just the sum of the haploid chromosomes of each parent.
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