CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 48 , Issue 4
Showing 1-19 articles out of 19 articles from the selected issue
  • II. Chromosomal rearrangements, puffing and nucleolar-organizer
    Lucian Gavrila
    1983 Volume 48 Issue 4 Pages 741-748
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    In Chironomus sp., Mycetophila and Rhagoletis cerasi the chromosome rearrangements, puffing and nucleolar-organizing functions have been studied. Some details on “functional structures” in polytene chromosomes of these dipteran species are presented. Some aspects regarding cytology of polytene chromosomes in Mycetophila and Rhagoletis are presented for the first time.
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  • C. B. S. R. Sharma, B. N. Behera, D. S. S. Raju, B. G. S. Rao
    1983 Volume 48 Issue 4 Pages 749-752
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Four systemic fungicides-thiabendazole, fuberidazole, carboxin and oxycarboxin have been tested for effects on chiasmata in barley. All compounds excepting thiabendazole have depressed chiasma frequencies significantly. The source of such a variation could be laid a) fairly very early in development as the treatment was done during the first DNA synthetic period in the seeds or b) much later during development because the compounds are systemic in nature. The observations are likely to be useful in genetic toxicology and in dealing with experimental crop populations.
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  • I. Karyology of Chondrostoma lusitanicum Collares-Pereira, 1980
    M. J. Collares-Pereira
    1983 Volume 48 Issue 4 Pages 753-760
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The karyotype of Chondrostoma lusitanicum Collares-Pereira, 1980 is established by the analysis of 246 kidney methaphasic plates obtained in 33 specimens.
    This Iberian endemic species is characterized by presenting the most common diploid number found in the known Cyprinids, that is, 2n=50 (NF=94). The karyotype is asymmetric and its haploid formula is 8: 14: 3. There is no evidence neither of intra and/or inter-individual polymorphism, nor of heterochromosomes, just like in the described holartic Cyprinids. Morphometric data concerning the six more conspicuous chromosome pairs are presented and discussed.
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  • XIV. Effect of the insecticide Dipterex “trichlorphon” on Vicia faba plant
    Soheir M. Amer, Enaam M. Ali
    1983 Volume 48 Issue 4 Pages 761-770
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The effects of the insecticide (Dipterex or trichlorphon) have been studied on: root-mitosis, meisosis and pollen viability of Vicia faba plants (var. Giza 2). 0.5% solution of pure “Dipterex is used in the present study. Root-treatment for four hours caused distinct decrease in the mitotic index indicating mitotic inhibition. Disturbed meta and anaphases (where the chromosomes spread irregularly in the cell) comprised the main type of the observed abnormalities: Lagging chromosomes and anaphase bridges were also observed.
    Vicia faba plants were sprayed at the flowering stage with the insecticidal solution once and twice for two successive days. The two treatments induced a significant percentage of abnormal PMCs/plant. The types of abnormalities observed in meiosis were the same as those observed in mitosis, except chromosome stickiness which was observed in a high percentage in meiosis only. The phenomenon of chromosome stickiness has been discussed.
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  • Kusum Agarwal, P. K. Gupta
    1983 Volume 48 Issue 4 Pages 771-779
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. In the genus Trigonella, male meiosis was studied in six species and mitosis with the help of root tip was studied in nine collections belonging to six species. All the species were diploid having n=8 and 2n=16, except T. polycerata where the chromosome number was n=22.
    2. Meiosis was normal in all the cases. Chiasmata frequency/bivalent varied from 1.77 (T. foenum-graecum) to 1.98 (T. corniculata).
    3. Total chromatin length varied from 16.36μ (T. cretica) to 33.05μ (T. foenum-graecum).
    4. The intraspecific variability in chromatin length was observed in four accessions of T. coerulea, suggesting that the species was dynamic and always undergoing a process of change.
    5. Species were classified according to classification of Stebbins (1971). Only four of the 12 catagories were represented, indicating that the degree of asym metry was low.
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  • Kusum Agarwal, P. K. Gupta
    1983 Volume 48 Issue 4 Pages 781-793
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. In the genus Medicago male meiosis was studied in 14 species and mitosis with the help of root tips was studied from 19 collections belonging to 15 species. Most of the species were diploids having n=7 or n=8, only two species (M. sativa and M. scutellata) were tetraploids having n=16.
    2. Chiasmata frequency/bivalent varied from 1.77 (M. tornata) to 2.18 (M. scutellata).
    3. Total chromatin length varied from 14.36μ (M. tuberculata) to 48.56μ (M. sativa Coll. no. 1766).
    4. On the basis of karyotypes, species were classified according to the classification of Stebbins (1971). Only four of the 12 categories were represented by the species examined, indicating that the degree of asymmetry was low.
    5. Accessory chromosomes were recorded from root tip cells in four taxa belonging to three species (M. intertexta, M. littoralis and M. tornata).
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  • Kusum Agarwal, P. K. Gupta
    1983 Volume 48 Issue 4 Pages 795-801
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. In the genus Tephrosia male meiosis was studied in 8 species and mitosis with the help of root tip was studied in three species. The chromosome number was invariably found to be n=11 and 2n=22. Chromosome number in three species (T. maxima Pers., T. oxygona Welw. ex Baker and T. polystachya E. Mey) were reported for the first time.
    2. The meiosis was normal in all the cases. The chiasmata frequency/PMC varied from 16.15 (T. bracteolata) to 21.00 (T. maxima).
    3. The total chromatin length varied from 15.78μ (T. purpurea) to 26.15μ (T. bracteolata).
    4. The chromosomes were mainly metacentric and did not vary greatly so that the level of asymmetry was low.
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  • Yoshito Asano
    1983 Volume 48 Issue 4 Pages 803-809
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Meiotic metaphase I in PMCs was observed in seven interspecific hybrids in Lilium. The extent of chromosome pairing was found to vary according to the cross combination. No significant differences were recognized between the observed and calculated random frequency distributions for the number of bivalents/cell except for two cases. The random distribution of bivalents in cells is explicable as the result of the chance pairing of homoeologous chromosomes with low attraction. ‘Attraction range’ specific to each hybrid was given. There was a tendency that chiasma frequencies per bivalent were in proportion to the mean pairing rates.
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  • Marjorie P. Maguire
    1983 Volume 48 Issue 4 Pages 811-818
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    A new fixation technique has permitted more detailed light microscope observations of the leptotene to pachytene meiotic progression of maize microsporocyte chromosomes than has been possible following use of traditional fixatives. With use of this new procedure, squash preparation produces excellent spreading of chromosomes at stages where the tightness of the synizetic knot has previously prohibited analysis. Using this technique, a novel finding was that at zygotene stage, extensive homologue alignment, which can be either loose or closely parallel, but at greater than synaptic distance, apparently precedes synapsis. Synaptic initiation is frequently intercalary and there may be a number of sites of initiation per bivalent. Telomeres and conspicuous heterochromatic regions are often among the last parts to synapse. The clear alignment of homologues in advance of synapsis is regarded as strongly suggestive of the existence of multiple chromosome sites which are active at homologue pairing and function in advance of synapsis.
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  • Reiko Karasawa, Katsumi Ueda
    1983 Volume 48 Issue 4 Pages 819-826
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The development and disappearance of the nuclear vacuoles in pollen mother cells of Haplopappus gracilis were described and the relationship between nuclear vacuoles and the synizesis was discussed. Nuclear vacuoles originated by the invagination of nuclear membanes at the early leptotene stage. These nuclear vacuoles increased in volume, and occupied about one-half of the nuclear volume at the late synaptic stage. The fully grown nuclear vacuoles displaced the karyoplasm towards one side of the nucleus. This appearance just corresponds to the synizesis observed with the light microscope. Nuclear vacuoles gradually decreased in volume by releasing their sap into the cytoplasm from the diplotene through the diakinesis.
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  • Margaret L. Couture, Matthew J. Freund
    1983 Volume 48 Issue 4 Pages 827-832
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Menstrual blood was previously reported to contain large numbers of endometrial, squamous metaplastic, parabasal, and superficial and intermediate squamous epithelial cells. This report describes additional types of exfoliated cells found in the menstrual blood of three women collected by use of a new vaginal collection device. These included normal endocervical cells, benign squamous “pearls” (formed by the superficial and intermediate cells of the stratified squamous epithelium of the ectocervix or vagina), and parabasal cells which may originate by squamous metaplasia within the endocervical epithelium. The exfoliative cytology of menstrual blood presented in this paper and previous papers by these authors, includes all of the cell types obtainable by the conventionally used cell collection methods. The new collection technique used has certain advantages over the conventionally used cell collection methods, since it is noninvasive, convenient, and allows direct delivery or mailing of the sample by the patient to the laboratory.
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  • M. S. Chennaveeraiah, K. K. Joshi
    1983 Volume 48 Issue 4 Pages 833-841
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Detailed karyomorphological study of 19 species and 27 collections of Linum is made. The study reveals the presence of n=8, 9, 10, 13, 14, 15, 16, 17, 18 and 30 chromosome numbers within the genus. However, the number n=9 and n=15 predominate over other numbers. L. pubescens is studied and karyotype of 13 species is described for the first time. New chromosome numbers are reported for 6 species. On the basis of general morphology and karyotype a phyletic tree is drawn to show the line of evolution within the genus and interrelationship among the species. The basic chromosome number is interpreted as x=9.
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  • S. G. Bharati, M. S. Chennaveeraiah
    1983 Volume 48 Issue 4 Pages 843-846
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Lychnothamnus barbatus collected from Karnataka, India has a large number of chromosomes with distinct karyomorphology and morphologically larger measurements and hence treated as new of variety of L. barbatus var. gigantii var. nov.
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  • I. Meiotic studies in South Indian bananas
    P. K. Agarwal
    1983 Volume 48 Issue 4 Pages 847-852
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Meiotic studies were conducted in 17 South Indian banana varieties. Different cytological abnormalities were observed. Sterility in diploid varieties of banana was found to be genic which operates to bring about disorganization of chromosomes and microspores at different stages of development. None of the variety showed restitution nuclei formation.
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  • Saleem A. Qureshi
    1983 Volume 48 Issue 4 Pages 853-858
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Some of the testicular cysts of one-day-old tea-tortrix moth, Homona magnanima Diakonoff were observed to contain degenerating spermatids which projected variable number of appendages in the flagellar region. These appendages are structurally similar to appendages on the flagellar region of Lepidopteran sperms, but seem to far exceed in number. The significance of these appendages is obscure and needs further work to understand their chemical nature and function.
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  • Aiko Sakai-Wada
    1983 Volume 48 Issue 4 Pages 859-867
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Studies were made on the fine structure and chemical components of the synaptonemal complex (SC) of pollen mother cells of Tradescantia reflexa. The SC of T. reflexa consists of three partite structures: a central element consisting of two tubules of about 20 nm width, which are twisted together, a lateral element appearing as an electron-opaque line of 25-35 nm width, and transverse filaments of about 10 nm width which connect the central and lateral elements.
    The central element contains basic protein and a small amount of DNA and RNA. The lateral element contains basic protein and small amounts of DNA and RNA. The transverse filaments contain non-basic protein.
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  • Singo Nakazawa
    1983 Volume 48 Issue 4 Pages 869-872
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Cellular morphogenesis results from concentration gradients of cellular substances, and the gradients are caused by cellular polarity, which is analyzed into “intercellular polarity vectors” (IPVs). The IPV is defined as the position vector of displacement of cellular substances.
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  • Toshiaki Kameya
    1983 Volume 48 Issue 4 Pages 873-878
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    To improve the dextran method for plant cell fusion, the effects of pH, inorganic salts and electrical stimulus on fusion were investigated using protoplasts aggregated by dextran solutions. Fusion frequency was enhanced by high pH conditions or by electrical stimulus. Fusion took place during dilution of dextranprotoplast mixtures with Mn++ and Ca++ solutions. Protoplasts treated by the dextran method developed into colonies after 3-4 weeks. These results demonstrate that the dextran method is useful for understanding fusion mechanism and for inducing somatic hybrids practically.
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  • Q. N. Ahmad, E. J. Britten, D. E. Byth
    1983 Volume 48 Issue 4 Pages 879-892
    Published: December 25, 1983
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Karyotypic analysis is difficult in the soybean which has numerous small chromosomes, not readily recognizable morphologically. Investigation is complicated by the technical problems of spreading and staining the chromosomes.
    A quantitative approach to karyotypic analysis is described using data from six cells selected on the basis of degree of contraction of the chromosomes and which were shown to be homogeneous statistically. Scatter diagrams were prepared from data on total length and arm ratios of the chromosomes to determine the homologous pairs of chromosomes. These data from the haploid complement values of the six cells were then plotted to identify as far as possible the individual chromosomes. Nine of the 20 chromosomes of the haploid complement were identified and described individually and the remaining 11 were characterized into classes based on length and arm ratio. A standard karyotype of the soybean is proposed.
    The method should be useful for karyotypic analysis of other species with problems similar to those of the soybean. The procedure should also prove useful for further work in the soybean itself, such as identification of chromosomes involved in monosomic, trisomic or other aneuploid conditions.
    This work is the first to provide a standard karyotype of the soybean.
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