CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 20, Issue 2
Displaying 1-10 of 10 articles from this issue
  • G. Tischler
    1955 Volume 20 Issue 2 Pages 101-118
    Published: August 31, 1955
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    1) Aus den mir bis Juli 1954 vorliegenden Daten errechnete ich folgende Prozentsätze für die diploiden und polyploiden Angiospermen, nachdem ich diejenigen Species, die möglicherweise diploide und polyploide Rassen im Gebiet besitzen, vorsichtshalber als “ununtersucht” fortließ. Dagegen wurden die Arten, für die nur in anderen Arealen derartige Rassen anzunehmen waren, in dem betreffenden infrage stehenden Gebiet eindeutig gewertet.
    Es ist klar, daß in kleineren Arealen die Artenzahl pro 1000 qkm entsprechend höher ist, als in größeren, die noch dazu keine all zu großen klimatischen Unterschiede aufweisen. In der Größe vergleichbare Areale wie Rumänien und Norrland (15:3) oder Ungarn und Island (22:5) zeigen besonders deutlich die Abnahme der Artenzahl von Süden nach Norden.
    2) Für Schleswig-Holstein berechnete ich den Polyploidiegrad der Arten, die ihre Hauptverbreitung nach Süden, S. W. oder S. O. einerseits, nach Norden andererseits haben.
    3) Rechne ich für Centraleuropa, Schweden und Groß-Britannien die Arten mit diploiden und polyploiden Rassen in meiner Gruppierung mit, da hier am ersten eine Wahrscheinlichkeit besteht, daß tatsächlich beide Rassen auch im Gebiet enthalten sind, ergibt das Für Island, S. W. Grönland und Spitzbergen sind keine Arten mit chromosomal verschiedenen Rassen aufgeführt, resp. sie sind von vorneherein als getrennte Arten aufgefaßt.
    4) Eine Untersuchung derjenigen Arten, die nicht bis Centraleuropa gekommen sind, ergibt (wieder unter Weglassung derjenigen, die möglicherweise diploide und polyploide Rassen besitzen) für
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  • Kenji Nakamura, Jin-ichi Kitada
    1955 Volume 20 Issue 2 Pages 119-132
    Published: August 31, 1955
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    1. Spermatogonial chromosomes of Grylloblatta sp. are found to be 30 in number, including an XY pair of sex-chromosomes. X is a large metacentric chromosome, its shorter arm being as long as the largest of the acrocentric autosomes. Y is not identified from the evidences at hand, but if a certain one of the largest acrocentric chromosomes is assumed to be Y, the situation would be analogous to what should be expected from the centric fusion of X with a member of a large acrocentric autosomal pair.
    2. In Oecanthus indicus and in an unidentified species the chromosomes are 19 in the male and 20 in the female. Accordingly, the condition of the sex-chromosomes is XO-XX, as usually found in the Orthopteroid insects. The chromosomes-complexes of both species are similar and very much alike to that of Oe. longicauda except for the presence of a small Y-chromosome in the latter. From the similarity of autosomal assortments and size variation of the Y found by Makino, it may probably be assumed that the XO-condition of the indicus-type has been derived from the apparatus of longicauda by gradual diminution of the Y-element until its complete disappearance. The evolutional process of the XO-condition found in Oe. nigricornis cannot be accounted for in the same way, since X is metacentric having two arms of almost equal length.
    3. The primitive condition of the sex-choromosomes in the Oecanthus group is assumed to be of XO-XX type, X being acrocentric. The evolutional process of these different types of sex-chromosomes in this group may be explained as follows: if breakage happened to occur in an X and translocation of its distal part to the centric end of the other had taken place in the female, metacentric neo-X and an acrocentric neo-Y would have been formed. The XO-XX condition of nigricornis may be of the metacentric neo-X, while the XY pair of longicauda would be consisted of an acrocentric original X and a neo-Y. The XO-XX condition of indicus-type, of which X being acrocentric, would have been brought about from XY-XX of longicauda-type by gradual diminution to complete disappearance of Y.
    4. The relation between acrocentric and metacentric types of the XO-XX conditon which are reported in closely related species of Orthopteroid insects would be interpreted in the same way.
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  • III. Meiosis
    V. S. Raman
    1955 Volume 20 Issue 2 Pages 133-147
    Published: August 31, 1955
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    Meiosis has been found to be normal in all the species. Abnormalities of cytokinesis were observed in the horticultural varities of J. sambac, namely virupakshi, adukkumalli and gundumalli. The nuclei in the tapetal cells of all the species are plurinucleolate. There was no indication of persistent nucleolus during meiosis, though its persistence was observed in root tip mitosis. The pollen mother cells have been found to occur in groups connected by protoplasmic strands. The presence of these do not seem to interfere with the meiotic process. Their occurrence in all the species appears to be a general feature.
    Evidence from secondary association shows that the 26 chromosomed species are likely to be in the nature of allotetraploids derived from the basic number 7.
    One autotriploid of J. sambac var. gundumalli and one autotetraploid J. flexile have been described, and their possible origin discussed in the light of the available data.
    The probable origin of the various species in Jasminum have been discussed in which polyploidy and gene mutation may have played a major role.
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  • P. N. Bhaduri, P. N. Ghosh
    1955 Volume 20 Issue 2 Pages 148-149
    Published: August 31, 1955
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
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  • Shams-ul-Islam Khan
    1955 Volume 20 Issue 2 Pages 150-156
    Published: August 31, 1955
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    1. Heterozygous T5-6c with homozygous inversion in chromosome 5 has been used to study the effect of exposure to 36±2°F on crossingover.
    2. Crossingover frequency has been calculated by ascertaining directly the frequency of the crossover quartet.
    3. Data on the effect of exposure of heterozygous T5-6c with homozygous inversion in chromosome 5 to 36±2°F have been presented.
    4. The presence of an inversion increased the frequency of chains from 40% to 60%.
    5. The period of maximum response to the influence of low temperature exposures is 4-6 day period in the 5th week. The increase in crossover frequency is from 10.6% to 12.9% almost approaching the maximum limit of 13.2%.
    6. It has been suggested that the effect of low temperature on crossingover is through its influence on interference.
    The writer wishes to express his deep appreciation of Dr. C. R. Burnham for his continued interest, kind criticism and many helpful suggestions during the earlier course of this investigation. He is thankful to him for the stocks he made available for research. To Dr. A. O. Dahl of the Department of of Botany, University of Minnesota the writer is indebted for constructive crticism during the later course of this investigation.
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  • Ikuo Takeuchi, Masashi Tazawa
    1955 Volume 20 Issue 2 Pages 157-165
    Published: August 31, 1955
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    1. The capacity of D. discoideum to form the pseudoplasmodium and the fate of morphogenesis under the influence of various external agents were studied.
    2. The formation of the pseudoplasmodium and further processes of morphogenesis were remarkably checked and delayed by KCN whereas inhibition by compounds such as monoiodoacetic acid and NaF was not conspicuous.
    3. The presence of oxygen was required for the movement of the myxamoebae towards an aggregation center and the further stages of morphogenesis are increasingly sensitive to low oxygen tension. On the other hand, high oxygen tension such as that of pure oxygen had no effect on morphogenesis.
    4. The pseudoplasmodium formation was remarkably inhibited by DNP and NaN3 even at the concentration where the respiration of the myxamoebae was rather stimulated than reduced.
    5. Potassium and calcium ions showed contradictory effects on the number and the size of pseudoplasmodia as well as on the rate of morphogenesis.
    6. The normal processes of morphogenesis were observable at pH 5, 6 and 7, but not at pH 3 and pH 8.
    7. The morphogenetic process in relation to the population densities of the myxamoebae was investigated.
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  • P. A. Hyypio, Te May Tsou, G. B. Wilson
    1955 Volume 20 Issue 2 Pages 166-176
    Published: August 31, 1955
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
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  • G. B. Wilson, P. A. Hyypio
    1955 Volume 20 Issue 2 Pages 177-184
    Published: August 31, 1955
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
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  • Carl C. Lindegren, Dan O. McClary, Marion A. Williams
    1955 Volume 20 Issue 2 Pages 185-196
    Published: August 31, 1955
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    All metachromatically staining substances were originally thought by Lison (1935a; 1935b) to be the sulfuric esters of high-polymeric carbohydrates. Michaelis (1947) found that high-polymeric carbohydrates with carboxyl groups such as the capsular substances of pneumococci and mucin stain metachromatically (purple to red) with toluidine blue. Wiame (1946) found that metaphosphate also stains metachromatically. Both Wiame and Michaelis have shown by spectrophotometric analyses that metachromasy (when toluidine blue is used as the stain) is dependent upon (1) the concentration of metaphosphate, (2) the concentration of dye, and (3) the condition of the metaphosphate.
    The following tests devised by Grimme (1902) for the detection of volutin (metaphosphate), have been retained in general use: 1) metachromatic staining with dilute methylene blue, 2) extractability from unfixed cells with hot water at 80°C in five minutes, and 3) retention of the stain after treatment with 1 per cent sulfuric acid. Acid fastness is superior to the occurrence of metachromasy as a test for the presence of volutin.
    A cytological investigation of the location of metaphosphate (volutin) in the yeast cell was made in two types of preparations: 1) fixed impression smears and 2) progressively stained living cells. Essentially the same results were obtaned with both preparations except that the vacuoles were destroyed by drying the impression smears. The results showed that volutin (metaphosphate) is confined to the nuclear vacuole.
    There are three items which have led to erroneous conclusions concering the location of metaphosphate. The spindle, which is not visible in the unstained cell, often appears after staining as a clear area and is mistaken for the vacuole. Heavy deposits of glycogen similarly appear in the stained cell as clear areas and have been mistaken for the vacuole. The mitochondria, which are obvious in the cytoplasm, are destroyed by the staining and have been confused with the chromosomes covered with volutin which appear after staining.
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  • D. U. Gerstel
    1955 Volume 20 Issue 2 Pages 197-198
    Published: August 31, 1955
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
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