CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 62, Issue 2
Displaying 1-15 of 15 articles from this issue
  • A. Badr, S. F. Khalifa, A. I. Aboel-Atta, M. M. Abou-El-Enain
    1997 Volume 62 Issue 2 Pages 103-113
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Taxonomic relationships in the Solanaceae have been discussed based on chromosomal criteria of 45 species; including three new records; belonging to 15 genera representing eight of the 14 currently recognized tribes; and their phylogeny based on variation in chromosome number is proposed. In contrast to the traditional subfamilial delimitation of the family (Murray 1945, D'Arcy 1979, 1991, Armstrong 1986) cytological data indicate that subfamily Cestroideae is less evolved than subfamily Solanoideae. These data further support the isolation of Cestrum in a separate tribe. The isolation of tribe Salpiglossideae in a separate family as proposed by Hutchinson (1973) and the delimitation of both Datura and Hyoscayamus as two separate tribes as done by D'Arcy (1991) is strongly supported by cytological data. In agreement with both Wettstein (1895) and D'Arcy (1991) the delimitation of Nicandra in a separate tribe is further recommended. However, the separation of Atropa and Lycium from the tribe solaneae are not likely to be justified based on cytological ground.
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  • Eduardo J. Greizerstein, Carlos A. Naranjo, Lidia Poggio
    1997 Volume 62 Issue 2 Pages 115-120
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The karyotypes and total DNA content of five wild species of Amaranths (Amaranthus bouchonii (2n = 32), A. hybridus (2n = 32), A. quitensis (2n = 32), A. powellii (2n = 34) and A. spinosus (2n = 34)) were studied. These data are compared with that of the four grain species. The results indicate that this kind of studies allows the differenciation of these nine species of Amaranthus. There are differences in the karyotype formulae and asymmetry indexes A1 and A2. Moreover, this kind of studies let some taxonomical controversies be solved, for instance, to maintain A. bouchonii as a independent taxa of A. powellii.
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  • Chieko Saito, Makoto Fujie, Atsushi Sakai, Haruko Kuroiwa, Tsuneyoshi ...
    1997 Volume 62 Issue 2 Pages 121-132
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    We examined the differentiation of the generative and the vegetative cells of tobacco (Nicotiana tabacum SR-1) by a newly developed cytological method using fluorescence microscopy after embedding of samples in Technovit 7100 resin. The extent of condensation of the chromatin in generative and vegetative nuclei was measured semi-quantitatively in sections of uniform thickness by microphotometry. The extent of chromatin condensation in the generative nucleus was about 5 to 10 times as high as the vegetative nucleus throughout pollen maturation which lasted about 5 days. Such a difference was clear immediately after PM I, indicating that the differentiation of the two cells had already started as soon as PM I has finished. Maturing generative cells had almost as much condensed chromatin as chromosomes of PM I. We also examined whether the generative cell has the potential for gene expression. The localization of RNA was visualized by staining with acridine orange. The results revealed the cytoplasm of the generative cell contained RNA and the density of RNA was as high as in the vegetative cell. This result suggests that the generative cell has the potential for gene expression in spite of the highly condensed chromatin in the nucleus. Furthermore, the generative nucleus in the mature pollen retained small nucleoli. Their presence implies that rRNA is synthesized consistently in generative cells.
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  • S. Rai, A. B. Das, P. Das
    1997 Volume 62 Issue 2 Pages 133-141
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Extensive karyotype analysis including determination of somatic chromosome number, total chromosome length and volume and estimation of 4C DNA amount were carried out on 9 different cultivars of ginger (Zingiber officinale Rose.) for the first time. A significant variation in nuclear DNA amount was recorded at the cultivar level. The 4C DNA amount varied from 19.663-24.102 pg in the cultivars studied. The correlation coefficient studies showed that the 4C DNA content and genomic chromosome volume were interdependent. The structural alteration of chromosomes as well as loss or addition of highly repetitive sequences in the genome showed variation in the DNA amount at cultivar level, but a marginal variation in nuclear DNA content at the cultivar level indicated a close relationship between them.
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  • J. G. Seijo, A. L. Ramos, S. Sato
    1997 Volume 62 Issue 2 Pages 143-150
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Pea seedlings were incubated in sorbitol solutions of various osmotic potentials (ψs) in order to study the effects of osmotic stress on cell division, and its relationship with root growth and water status. A net promotion of growth occurred when roots were subjected to moderate osmotic stress (ψs =-0.65 MPa), but decreased at lower ψs. The water potentials of the mature and elongating zones decreased concomitantly with the reduction of the sorbitol ψs. Turgor increased slightly in both zones when there was an increment of growth (ψs =-0.65 MPa), afterwards decreasing until almost zero when medium was ψs =-2.04 and-2.7 MPa. Mitotic index was enhanced at moderate osmotic stress but decreased when the stress became higher, in accordance with the patterns of growth rate and turgor. However, the MI was not zero even when the growth stopped and the turgor of cells was lost. Analysing the mitotic phases at the lowest ψs an inversion of their frequencies was observed when compared with an active meristem : prophases and anaphases decreased in favour of metaphases and telophases. Moreover, the observation of scattered metaphasic chromosomes, chromosome amalgamation and the occurrence of several micronuclei in telophase-like cells indicates serious cell cycle disturbances. Therefore, our results suggest that osmotic stress affects the cell division in two different ways. First, cells enter Go because of the adverse environment and, second, microtubules depolymerize owing to the low water potential of cells and turgor loss, affecting the functionality of mitotic spindle, phragmoplast formation and cell wall expansion.
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  • J. G. Seijo, A.L. Ramos, S. Sato
    1997 Volume 62 Issue 2 Pages 151-156
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Epicotyls of pea seedlings incubated for 48 hr in sorbitol solutions of diffbrent osmoticpotentials reduced their growth rate and reached nearly 20%of the control whenψs was lowerthan-0.65 MPa. There was a decrease of water potential in the mature tissue accompanyingthe decrease in sorbitolψs. However, turgor was kept almost constant even under the moststressingψs. In the elongating zone of the stems, there was a steep reduction of theψw whenseedlings were incubated at-0.65 MPa, then, it remained almost constant decreasing againonly at-2.7MPa. Despite the reduction ofψw, turgor was kept constant in all the treatments.Mitosis reduced whenever osmotic stress was applied, and the lowest MI was about 50%of thecontrol. Neither abnormal chromosome behaviour nor alteration of the frequency pattern ofmitotic phases was observed. These results showed that in pea epicotyls, cell elongation wasmuch more sensitive to osmotic stress than cell division. The differential response of celldivision to osmotic stress between shoots and roots is discussed.
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  • H. Flores-Olvera, P. Mercado-Ruaro
    1997 Volume 62 Issue 2 Pages 157-162
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The meiotic chromosome numbers for 18 species of Atriplex section Obione (Chenopodiaceae) are presented. This is the first report for Atriplex abata, A. elegans, A. linifolia, A. minuscula, A. parishii, A. pueblensis, A. tampicensis, A. texana and A. thornberi. Photographs of the meiotic figures of 12 species are presented. All the species are diploid with 2n = 18, except for Atriplex argentea, A. cordulata, A. coronata and A. leucophylla tetraploids with 2n = 36. The basic chromosome number (x = 9) for the section is confirmed. Atriplex argentea, with the broadest geographic distribution, has at least two ploidy levels. All the tetraploid species occur in southwestern United States, the area of greatest diversity of the section Obione. Chromosome numbers appear to have taxonomic value and allopolyploidy might have played an important role in the evolution of the section.
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  • Nagwa H. A. Hassan
    1997 Volume 62 Issue 2 Pages 163-170
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The karyotype of the fat sandrat Psammomys obesus obesus from Egypt has been investigated. The diploid number of its chromosomes is 2n = 48. According to the relative chromosome length and the centromeric index, the autosomes were classified into 14 pairs of metacentrics and 9 pairs of telocentrics. The X-chromosome is represented by an outstandingly large metacentric element. The Y-chromosome is also a large metacentric falling in length between the second and the third pairs of autosomes. The constitutive heterochromatin, as revealed by C-banding technique is localized at the centromeric regions of the autosomes, different regions along the length of the X-chromosome (about 6.7-7.4% of its length) and one entire arm of the Y chromosome. The other arm showed heterochromatin bands homologous to that of the short arm of the X chromosome. In meiosis, the behaviour of the sex chromosomes was followed including types of association and the mode of segregation of the chromosomes. It has been suggested that the increase in the size of the sex chromosomes is mainly due to autosomal translocation.
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  • A. J. Alberdi, A. S. Fenocchio
    1997 Volume 62 Issue 2 Pages 171-176
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Karyotypic studies on five species (Characidae, Tetragonopterinae) from Argentina were carried out. Mitotic preparations from the kidney tissues were made by direct and short term culture methods. C-banding and silver staining was performed by conventional techniques. Astyanax bimaculatus, Gymnocorhimbus ternetzi and Moenkhausia sanctaefilomenae showed 2n = 50 chromosomes, with different karyotypic formulaes. Tetragonopterus argenteus showed 52 chromosomes and Astyanax schubarti 2n = 36 chromosomes. One pair of NORs was detected in most of species except in A. bimaculatus which showed numerical variation (1-6 carrier chromosomes) and size heteromorphism. The present paper reports the first cytogenetic study on the Tetragonopterinae from Argentina.
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  • Antonina Natyaganova, Dmitry Scherbakov, Alexander Graphodatsky
    1997 Volume 62 Issue 2 Pages 177-180
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    G-banding was successfully demonstrated in chromosomes of Baicalasellus angarensis (Isopoda, Crustacea) using a simple and reproducible technique. The obtained bands were numerous and distributed along the whole length of the chromosomes. The number of the G-bands mached interrelated with the condensation of chromosomes. The bands of homologous chromosomes in some cells were matchable. C-banding patterns in chromosomes of B. angarensis have also been investigated. The constitutive heterochromatin is located in centromeric and interstitial position of several chromosomes.
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  • A. Uchino, L. Wang
    1997 Volume 62 Issue 2 Pages 181-189
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The C-band polymorphism of chromosomes in Paris tetraphylla (2n = 2x = 10) was confirmed in the plants from the four populations, i.e., Miike (Mi), Kunimi (Kn), Kikuchi (Kk) and Aso (As), in Kumamoto Prefecture of Kyushu. The five chromosomes, A, B, C, D and E, constituting a genomic set were polymorphic for the C-banded patterns, respectively. The number of different types due to the patterns of C-banded chromosomes was 5 in each of chromosomes A, B and E, 3 in C, and 4 in D. In addition, small telocentric supernumerary chromosome was C-banding positive in its entire arm.
    The patterns of occurrence of various types of chromosomes A to E were more or less similar between Mi and Kn populations, there being similar environmental conditions, including vegetation. On the other hand, Kk and As populations were different from the other populations in the patterns of occurrence of various chromosome types and in their environmental conditions including vegetation. Therefore, it might be considered that different chromosome types due to the patterns of C-bands distribute according to the adaptability to environmental conditions including vegetation among the populations. This speculation might be supported by the occurrence of supernumerary chromosomes in both Kn and As populations but absence in both Mi and Kk population.
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  • Joel S. Noumoff, Geeta M. Joseph, Randolph B. Deger, Runa Hatti, Shami ...
    1997 Volume 62 Issue 2 Pages 191-194
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The significance of fragile sites on human chromosomes and their relationship to cancer break-points resulting in translocation has been debated for over a decade. It is, however, still controversial if fragile sites are also the sites of translocations resulting in neoplastic transformations. We debate yet another aspect of translocation which is whether chromosomal exchange takes place after deletion or undeleted chromosomes could exchange parts directly. On the basis of three cases which are presented in this study, we have demonstrated objectively and for the first time translocation at the fragile sites and also translocation directly between undeleted chromosomes, providing proof in support of the exchange theory.
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  • Toshisuke Hiraoka
    1997 Volume 62 Issue 2 Pages 195-202
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Two kinds of poles, the PP and the MP, are manifested just prior to and during the synaptic stage of meiosis in the SMCs of Equisetum. A spectroscopic and ultracytochemical characterization of these poles has been carried out to elucidate their functions. The former pole not only works as the intracellular center of carbohydrate metabolism in this stage, but also as a possible supply center of intermediates for protein and fat biosyntheses. In contrast, the latter pole functions as the intracellular center of ATP production in this stage. This synaptic pole formation is causally related to the “chromosome and molecular pairing” of meiosis.
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  • N. Rubtsov, N. Serdyukova, E. Kaftanovskaya, F. Yang, L. Biltueva, N. ...
    1997 Volume 62 Issue 2 Pages 203-208
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    On the X chromosomes of the sheep, goat, Chinese muntjac, water deer, and roe deer, we have identified the regions which were homologous to the short arm of the cattle X chromosome by heterologous chromosome in situ suppression hybridization with the cattle X chromosome short arm specific DNA library probes generated by microdissection and TOPO-DOP-PCR amplification. Despite the chromosome rearrangements during karyotype evolution in pecorans, these homologous regions were each detected as one block on the X chromosomes of the above species.
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  • Milada Holecová, Maria Rozek, Dorota Lachowska
    1997 Volume 62 Issue 2 Pages 209-212
    Published: June 25, 1997
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    An analysis was made of C-banded karyotype of Otiorhynchus corvus Boh. The results indicate that the chromosome number is 2n = 22 and n_??_ =10 + Xyp. All autosomes and the X chromosome are metacentric, the y is dot-shaped. The examined karyotype shows only pericentromeric position of constitutive heterochromatin in all autosomes and the X heterochromosome. The y has a greater segment of constitutive heterochromatin and the rest of it is euchromatic.
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