CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 37 , Issue 3
Showing 1-18 articles out of 18 articles from the selected issue
  • IV. Interrelation between nucleus and phragmoplast
    L. V. Olah, J. J. Bozzola
    1972 Volume 37 Issue 3 Pages 365-376
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    A study of nuclear and phragmoplast association observed in digitonin-treated Allium sativum cells led to a tentative hypothesis that initiation of formation of the phragmoplast-cell wall complex is triggered by a message released by chromosomes of restituting nuclei. A similar theory is applied in an attempt to explain the multiple spindle and phragmoplast systems present in certain PMC's, coenocytic embryos, and non-cellular or nuclear endosperm. Tritiated thymidine and uridine incorporations suggest that digitonin does not interfere with DNA and RNA synthesis. Compounds structurally and functionally related to digitonin did not induce digitonin mitosis.
    Acknowledgements: The authors gratefully thank the S.I.U. Office of Research and Projects for financial support and the Merck, Sharp, and Dohme Research Laboratories for purification of digitonin. We also express our sincere gratitude to Drs. Tadashi Hirano and Akio Kushanagi for the valuable assistance granted the senior author during his stay at the Tokyo Metropolitan Isotope Center.
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  • R. B. Singh
    1972 Volume 37 Issue 3 Pages 377-381
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Karyotype measurements of two dioecious species of Rumex, namely, R. hastatulus (subgenus acetosa) and R. acetosella (subgenus acetosella) and their F1 hybrids; F1+=(R. hastatulus 2n=8) _??_×(R. acetosella 2n=42) _??_ and (R. hastatulus 4n=16) _??_×(R. acetosella 2n=42) _??_ were recorded. The acetosella chromosomes are much smaller than the hastatulus chromosomes and can easily be identified in the hybrids. A significant decrease in the size of the R. acetosella chromosomes (particularly the sex chromosome) and a compensating increase in the size of the R. hastatulus chromosomes were found in the F1 hybrid karyotypes when these were compared with the chromosome sizes in the parental karyotypes. Apparently the genetic and physiological balance resulted in shortening of the shorter chromosomes and lengthening of the longer chromosomes.
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  • Takuzo Yamada, Kaichiro Yanagisawa, Yosito Sinotô
    1972 Volume 37 Issue 3 Pages 383-388
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The cells of the cellular slime mold D. discoideum were harvested and suspended in salt solution and the supernatant of the cell suspension was then obtained. It was found that when the cells of the mutant strain KS17 were treated with the supernatant, differentiation into spores was inhibited, although fruits were normally formed, and that when they were treated with the highly concentrated supernatant, the differentiation into both the spores and stalks was repressed and the development ceased at the stage prior to fruiting. When the differentiation was inhibited, the cells remained in a completely undifferentiated stage. The inhibitory effect of the supernatant is due to the action of inhibiting substance secreted by the cells. The substance was secreted by the cells of all strains examined in D. discoideum. However, it only acted on KS17 cells to inhibit the differentiation.
    KS17 cells were treated with the supernatant at different stages of development. It was found that inhibitory effect varied remarkably with the stages. The effect was maximum at the aggregation stage and none at the migration stage. Some effect was also observed at the early culmination stage, but after this stage no effect was observed. The reason and significance of the different inhibitory effect at dif-ferent developmental stages were discussed.
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  • J. V. Pantulu, V. Manga
    1972 Volume 37 Issue 3 Pages 389-394
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Plants with two extra chromosomes were obtained in the progeny of a triploid plant. The extra chromosomes were deficient for short segments in one of their arms. Meiotic studies in PMC's of these plants showed that these extra chromosomes were not pairing with any of the other chromosomes of the complement but were only pairing among themselves. In cells with the extra chromosomes there was a significant variation in PMC' chiasma frequency. Meiotic abnormalities like differential condensation of chromosomes, persistent nucleoli and cytomixis were observed. The effect of these extra chromosomes on the behaviour of the other chromosomes was compared with the effect of B's when present in numbers of five or more on the A-chromosomes.
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  • C. de la Torre, G. Giménez-Martín
    1972 Volume 37 Issue 3 Pages 395-398
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The variability of chromatic and heterochromatic zones in human acrocentric chromosomes is studied. There is a small variability in the latter, and that of heterochromatic zones seems positively related to the participation of the chromosome in the so-called “satellited association”.
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  • Shiu Yeh Yu, C. N. Sun
    1972 Volume 37 Issue 3 Pages 399-414
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Elektron- und lichtmikroskopische Studien wurden an den Septalzellen der Lungen von Ratten in verschiedenen Stadien der Entwicklung ausgeführt: Die Studien waren an embryonischen, neugeborenen, nach der Entwöhnung saugenden und erwachsenen Ratten. Biochemische Analysen dieser Lungengewebe wurden gleichfalls gemacht. Die Septalzellen der Lunge stammen von unentwickelten Zellen des Mesenchyms. In früherer Periode der Entwicklung der alveolaren respiratorischen Einheit veränderten sich die mesenchymalen Zellen von kubischer oder ovaler Form zu spindelartige Zellstruktur. Während dieser ganzen Entwicklung wurde eine Ansammlung von Fett und Glykogen in den Septalzellen beobachtet. Die Ablagerung von Fett in diesen Zellen nahm progressiv zu und erreichte das Maximum ungefähr am 15. Lebenstag und nahm von da an allmählich ab. Es ist nicht bewiesen, daß das Fett in den Zellen, ein Produkt aus dem zirkulatorischen Fett, abgelagert wurde. Daher muss man annehmen, daß das Fett in den Septalzellen auf neue Fett-Syntheses zurückzuführen ist.
    Kollagen des Interstitiums wurde unmittelbar nach der Geburt beobachtet. Elastische Fasern dagegen konnten erst nach ungefähr 17 Tagen nach der Geburt gefunden werden. DNS-Gehalt der Lunge vermehrte sich sehr schnell vor der Entwöhnung, dann langsamer. Die Proportionen von RNS zu DNS waren grösser nach 18-20 Tagen. Diese Daten deuten darauf hin, daß Elastin und Kollagen erst nach der Differenzierung der Septalzellen synthetisiert werden. Im Verlaufe dieser Differenzierung können die mesenchymale Zellen der Lunge in ein Fett-Ansammlungsstadium eintreten, ähnlich wie andere Zellen mesenchymalen Ursprungs zeigen. Später jedoch ändern these Zellen ihre Struktur and funktionieren als die Septalzellen. Die Fett-tragenden Septalzellen spielen wahrscheinlich eine bedeutende Rolle in der neonatalen Periode der Entwicklung der Lunge.
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  • B. A. Phadnis, M. N. Narkhede
    1972 Volume 37 Issue 3 Pages 415-421
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Chromosome behaviour was studied in colchicine induced polyploids in their advanced generations. Polyploids were isolated as sterile, partial fertile and fertile tetraploids. The abnormalities like asynaptic behaviour, univalent formation, non-disjunction of chromosomes, unequal distribution at anaphasic separation, laggards and micronuclei were observed. Fertile plants showed a trend towards “bivalency” and were comparatively more productive.
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  • N. K. Bhattacharyya
    1972 Volume 37 Issue 3 Pages 423-433
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. Detailed karyotype analysis of Zephyranthes mesochloa has been made. In the normal complement, 2n=24 chromosomes have been observed in the present investigation, whereas previous study in the same species has shown 2n=48 chromosomes. The significance of this difference has been discussed. Previous record of chromosome numbers in the genus Zephyranthes has been reviewed. The lowest and the highest number recorded in this genus are 2n=12 and 2n=120 respectively.
    2. Extensive numerical variation in the somatic chromosome complements has been noticed in Z. mesochloa, including both hypodiploid and hyperdiploid numbers which range from 2n=7+1 fragment to 2n=102. In addition, occurrence of structural chromosomal alterations in the somatic complements has also been noted. The mode of origin of these numerical and structural alterations has been discussed in the light of previous data in the present and other species of this genus as well as other genera of asexually reproducing plants.
    3. Non-disjunction and endomitotic replication affecting all or several chromosomes of the complement have been suggested as possibly responsible for their origin. The evolutionary importance of such somatic alterations in species reproducing through vegetative means has been pointed out.
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  • N. K. Bhattacharyya
    1972 Volume 37 Issue 3 Pages 435-443
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. Sphenoclea zeylanica Gaertn. of the family Campanulaceae and Lobelia terminalis Clarke of the related family Lobeliaceae, the two being originally kept under Campanulaceae, have been studied cytologically. Chromosome number observed in them are:
    i) Sphenoclea zeylanica Gaertn. 2n=42
    ii) Lobelia terminalis Clarke 2n=14
    2. Their karyotype analysis reveals long metacentric chromosomes in L. terminalis and short chromosomes in S. zeylanica. x=7 has been suggested as the basic number for both the genera. Diminution in chromatin matter along with polyploidy as noticed here has been discussed in the light of recent data.
    3. A heteromorphic pair of chromosomes has been observed in L. terminalis. Significance of such structural alteration of chromosomes in evolution has been discussed.
    4. Taxonomic status of Sphenoclea has been discussed. Its relationship with Phytolaccaceae has been criticised on the basis of available cytological data in them. The retention of the genus within the Campanuloid complex has been suggested.
    5. The relationship of the two families, Campanulaceae and Lobeliaceae as mentioned by taxonomists has been confirmed from cytological studies.
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  • I. V. Sudhakaran
    1972 Volume 37 Issue 3 Pages 445-456
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The dry seeds of Vinca rosea L. were irradiated using different doses of gamma rays. The germinating seeds exhibits delay in the time of germination and reduction in the percentage of germination. A diminition in the rate of increase in the length of the seed roots with increasing dose of gamma rays is also observed. The mitotic abnormalities such as stickiness and clumping of the chromosomes, sticky bridges and structural changes followed by the bridges and fragments are quite frequently met with in the dividing cells in the present plants. These are relatively same as the usual characters observed in the actively dividing irradiated cells of root tip in other plants by previous workers. It is to be noted that in the present plant the cells of the root tips are not directly exposed to radiation and these cells are formed later in the root tips during germination of the irradiated seeds and it is quite likely that any metabolic imbalance can be induced in the cells. Thus these abnormalities of chromosomes during cell division cannot probably be attributed only to the direct effect of irradiation on the chromosomes but it is likely that these irregularities and others leading to mitoic delay and inhibition of mitosis are due to the formation of mitotic poison through the breakdown of micro- and macromolecules in the cytoplasm in the dividing cells during the germination of the irradiated seeds.
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  • V. Evolutional aspect of the degeneration of centrioles and the development of cell walls in the plant kingdom
    Bungo Wada
    1972 Volume 37 Issue 3 Pages 457-468
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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  • A. Yesoda Raj, A. Sudharsan Raj, G. Madhusudana Rao
    1972 Volume 37 Issue 3 Pages 469-477
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Seeds of SLO-13, a long duration paddy variety were treated with different doses of gamma rays from Co60 source and data on germination, survival, rate of growth, morphological variants and meiotic abnormalities in the M1 and viable and lethal mutants in the M2 were discussed. Beneficial mutants like dwarf, stiff strawed and early flowering were obtained in some treatments and their significance in plant breeding has been discussed.
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  • U. P. Singh
    1972 Volume 37 Issue 3 Pages 479-488
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Nuclear behaviour in the basidium and basidiospores of avenelia breyniae Syd. is described. Haploid chromosome complement (n=6) is determined from the metaphase I and II of the basidial cytology. Numerous aberrations are encountered during teliospore germination and nuclear behaviour in basidium and basidiospores. Possible consequences of these aberrant types are discussed in view of the hostparasite relationship.
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  • M. A. Q. Shaikh, M. B. E. Godward
    1972 Volume 37 Issue 3 Pages 489-495
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The present study deals with the mitotic consequences of gamma radiation induced chromosome breaks in L. sativus and V. ervilia following seed irradition. Various types of mitotic anomalies were encountered.
    These included:
    1. Single, double, triple, multiple, X-shaped and interlocked bridges. The double bridges lasted very long persisting upto the late telophase and often left pear-shaped projections in the daughter nuclei marking their positions.
    2. Centric and acentric fragments in the metaphase and laggards in the anaphase were present. The fragments were of different lengths and the majority of them were in pairs. There were also some rings, minute deletions, dicentric chromosomes and chromatids present.
    3. Unequal length of metaphase chromosomes showing much more variation in length than is observed in the normal karyotypes.
    4. “Condensed” and “non-condensed” micronuclei in the interphase cells were observed and there was increasing evidence indicating that some of these micronuclei divide and go to the daughter nuclei.
    5. Degenerated cells having little chromatin material and showing less stainability were present.
    6. Giant cells often having about double the size of the ordinary root meristematic cells were present only in the species V. ervilia.
    Probable causes of the production of mitotic abnormalities following seed irradiation treatment were discussed in the light of the findings of other workers.
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  • M. A. Q. Shaikh, M. B. E. Godward
    1972 Volume 37 Issue 3 Pages 497-505
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Mature and dry seeds of L. sativus and V. ervilia were irradiated with 5, 10, 15, 20, 25, 30 and 50 Krad doses of gamma rays (Co60) and M1 and M2 plants were grown along with the controls. Meiosis of both the generations were studied to detect and explain the types of chromosomal abnormalities produced at different stages of meiosis in the M1 generation and that were subsequently still present in the meiosis of the M2 generation. Meiosis in the control flowers of both the species was normal. The various types of abnormalities observed in the different stages of the Ml generation were as follows:
    Diakinesis: heavy fragmentation of the nucleolus; metaphase I: univalents, tetravalents, multivalents, fragments, complex interchanges, rings, clumped and unusual configurations and unorientated chromatin material forming a large, round and darkly stained mass when a few of the bivalents aligned at the equatorial plate; anaphase I: abnormal separation of the homologues, single and double bridges with or without fragments, anaphase I with laggards only, unequal numbers of chromosomes going to the poles; anaphase II: single bridges with or without laggards, anaphase II with laggards only, unequal volumes of chromatin material in daughter nuclei, unequal pollen grains, fused or twin pollen grains and very small pollen grains.
    In the M2 generation, very few meiotic aberrations were observed in both the species. They were as follows in the different stages of meiosis; diakinesis: fragmentation of the nucleolus; metaphase I: complex interchanges and configurations, fragments, unorientated chromatin material; anaphase I: lagging chromosomes in anaphase I; anaphase II: laggards in anaphase II, and unequal volume of nuclear material in the daughter nuclei.
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  • Yong Hoi-Sen, S. S. Dhaliwal, Teh Kok-Leng
    1972 Volume 37 Issue 3 Pages 507-511
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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  • Barbara Marczynska, Halina Pigon
    1972 Volume 37 Issue 3 Pages 513-517
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Cytogenetic studies of African cane rat (Thryonomys swinderianus) established a diploid chromosome number for this species 2n=44. Among 21 pairs of autosomes, one pair of large submetacentric chromosomes possess secondary constriction and satellites on the shorter arms. The X chromosomes are the largest metacentrics while the Y chromosomes is the smallest of the complement. The karyotypic similarities between African cane rat and other hystricomorph rodents are briefly discussed.
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  • Katsumi Ueda, Mihoko Sawada
    1972 Volume 37 Issue 3 Pages 519-523
    Published: September 25, 1972
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The DNA contents of akinetes at various developmental stages and vegetative cells in a species of Cylindrospermum were estimated from the intensity of fluorescence from these cells after treatment with coriphosphin solution.
    In the earliest stage of development the DNA content of akinetes was similar to that of vegetative cells. During maturation the DNA content increased and mature akinetes contained about thirty times that in vegetative cells.
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