CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 65, Issue 3
Displaying 1-16 of 16 articles from this issue
  • S. A. Haroun
    2000 Volume 65 Issue 3 Pages 225-230
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Cytogenetic and breeding studies were carried out on Panicum turgidum from Saudi Arabia (South west area). The materials were collected from 5 sites and grouped into two main groups according to altitude level. The first group include three sites of collection at see level, whereas the second one include two sites at altitude of 2600 m above see level.
    Karyotype structure of the first group accessions shows high similarity recording 30m+4sm+ 2t. Karyotype measurements of this group recording 1.93 μm mean length of chromosome and arm ratio of 1.15 with very low standard error reflect the low variation between chromosomes within the set. In contrast the structure of karyotype in the second group shows 26m+6sm+4t, with significant variation in chromosome length recording 2.26 μm and arm ratio of 1.26. This in addition to the high values of standard error reflect the variation among chromosomes in length and centromere position within the set.
    Meiotic behavior of the first group accessions shows a low percentage of disturbed cells com-pared to that of the second group. In contrast to the second group, normal chromosome association was also observed in the first group accompanied with high level of chiasma frequency. Close relationship was noted between chiasma frequency and regular meiosis in form of chromosome association.
    A strong relation was indirectly also noted between chiasma frequency and seed set either in self or open pollination conditions for the two groups. Similarity of karyotype, normal meiosis and high pollen fertility for the first group (see level altitude) pointed to high stability in genome structure assuming a high potential for self compatibility of the accessions. The second group (2600 m altitude level) shows low fertility associated very strongly with other parameters suggest the partial self-compatible habit at such rich vegetation area which increase the probability of crossing with relatively compatible grasses.
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  • Pourali Safar, Khazab Mahmood, Kiabi Bahram, Sheidai Masoud
    2000 Volume 65 Issue 3 Pages 231-234
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Cytogenetic studies of 2 populations of Capoeta capoeta have been investigated Karyotype analysis of these species showed that, the first population chosen from Sefidroud and Shahroud rivers of Roudbar township has 2n=150, NF=234 and the second population chosen from Golestan National Park has 2n=150, NF=230. Polyploidy has also been observed in these species. Polymorphism has been observed in fundamental number (NF).
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  • Maha A. Fahmy
    2000 Volume 65 Issue 3 Pages 235-242
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The mutagenic potential of copper sulphate was evaluated in vivo using different mutagenic end points. Three different dose levels 2.06, 4.13, 8.25 mg kg-1 b.wt. (1/16, 1/8, 1/4 LD50) were tested intraperitoneally in this study. Copper sulphate induced a significant and a dose dependent increase in the frequency of sister chromatid exchanges (SCE's) at the tested concentrations. Such frequency reached 9.1±0.5/cell (p<0.01) after treatment with the highest tested dose which was lower than the value of mitomycin C 12.5±0.5/cell as the positive control. The 2 higher doses induced a significant increase (p<0.05) in the percentage of micronucleated polychromatic erythrocytes. Moreover a sever toxicity of bone-marrow cells was observed after treatment with the highest tested dose where the percentage of polychromatic erythrocytes reached 18.90% compared with 7.90% for the corresponding control value. In germ cells chromosomal aberrations was observed in mouse spermatocytes after treatment with copper sulphate with a dose dependent relationship. The repeated dose treatment induced higher effect than single dose treatment. Significant increase of morphological sperm abnormalities were also recorded after treatment with the 3 concentrations of copper sulphate (3 successive doses). Such increase reached 13.18±0.85% after treatment with the highest tested dose which exceed the value of mitomycin C (11.10±0.87). The present results indicate that copper sulphate is genotoxic in the mice examined.
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  • Maha A. Fahmy, Fawzia A. E. Aly
    2000 Volume 65 Issue 3 Pages 243-252
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    N-Nitrosodiethanolamine (NDELA) constitutes a serious potential genotoxic and carcinogenic hazard. The mutagenic potential of NDELA was evaluated in mice in vivo using the 2 cytogenetic parameters, chromosomal aberration and sister chromatid exchange. Single oral treatment by gavage using different doses of NDELA 10, 20, 50, 100, 250, 400 mg kg-1 b.wt. induced an increase in the percentage of chromosomal aberrations in mouse bone-marrow as well as in mouse primary spermatocytes in a dose-dependent relationship. Such percentage was statistically significant at the doses ranging from 20-400 mg. Repeated dose treatment with the doses 50, 100, 250 mg kg-1 b.wt. NDELA for 3 consecutive days induced slight increase in the incidence of chromosomal aberrations over that of a single dose treatment. The results also show that NDELA is a potent inducer of sister chromatid exchanges (SCE's). Intraperitoneal treatment with the doses 100, 250, 400 NDELA induced a significant and dose dependent increase in the frequency of SCE's. Such frequency reached 14.90±0.68/cell and 18.20±0.48/cell (p<0.01) after treatment with the 2 higher doses 250 and 400 mg kg-1 b.wt. which exceed the corresponding value of mitomycin C (13.90±0.63) as the positive control. Concurrent administration of vitamin C (L-ascorbic acid) at a dose of 20 mg kg-1 b.wt. moderately minimized the genotoxic effects of NDELA in all experiments examined.
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  • J. A. Lisanti, E. Pinna-Senn, M. I. Ortiz, G. Dalmasso, S. Parisi de F ...
    2000 Volume 65 Issue 3 Pages 253-259
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The genus Akodon, comprising more than 60% of the species of the Akodontini, widely distributed in South America, presents many interesting cytogenetic atributes, such as an ample karyotypic variation (2n=10-52), intraspecific and intrapopulational polymorphisms of the autosomes and of the gonosomes, and, as in both species here studied, XY fertile females. We report a cytogenetic comparative study of A. azarae (2n=38) and of A. boliviensis (2n=40) specimens. In these species, only the sex chromosomes, the first autosomal pair and the small bibrachial autosome characteristic of the genus, can be identified in conventional preparations. Chromosome relative lengths of each species were determined from G-banded karyotypes, and a schematic representation of the G-banding patterns is presented. The comparison of these patterns shows that 16 autosomal pairs are “shared” chromosomes, corresponding to 88.3% of the autosomal complement of A. azarae and to 87.5% of that of A. boliviensis. Furthermore, A. azarae pair 2 (8.23% of its autosomal complement) has a banding pattern homologue to pair 15 and most of pair 12 of A. boliviensis, which indicates that this chromosome of A. azarae would basically result from a tandem translocation. Apparently, no correspondence exists between the remaining pair 16 of A. azarae and pair 11 of A. boliviensis.
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  • S. B. Ning, Y. C. Song, L. Wang, Y. Ding
    2000 Volume 65 Issue 3 Pages 261-270
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The highly conserved proto-oncogene c-myc and tumor suppressor gene p53 in animals has been shown to play a central role in regulating multiple developmental processes including growth, proliferation and differentiation, and are also 2 of the important genes associated with programmed cell death. Using the probes corresponding to the 2 genes derived from human, we detected and localized their DNA homologs in maize (Zea mays L.) at cytogenetic level for the first time utilizing chromosome in situ hybridization. For detection, techniques, 3, 3'-diaminobenzidine and fluorescence staining were utilized. Both of them gave the identical results. The signals of the test probe corresponding to c-myc were detected on 4L (the long arm of chromosome 4) and 5L and 1S (the short arm of chromosome 1) simultaneously. And those of p53 were localized on 5S, 1L, 3L and 9L simultaneously. These results further confirmed the existence of the homologs of the 2 genes in maize at DNA level. The improvements of FISH technique using heterologous probes were discussed.
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  • K. N. Venkatachalapathy, H. P. Puttaraju
    2000 Volume 65 Issue 3 Pages 271-275
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    C-banded chromosomes prepared from the 4 regional populations of Extorista sorbillans reveal the presence of characteristic large blocks of constitutive heterochromatin in the pericentric regions of all the autosomes. An intercalary band localized on short arm of one of the homologues of VI chromosomes in males of Bangalore population appears to be an interesting feature as it was absent in all the males and females of other populations, of Chitradurga, Kolar and Hassan. The sex chromosomes (X, Y) of all the above populations were characterized by complete C-positive heterochromatin.
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  • A. A. El-Ghamery, A. I. El-Nahas, M. M. Mansour
    2000 Volume 65 Issue 3 Pages 277-287
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The present investigation was carried out to study the cytological effects of the herbicide atrazine on Allium cepa and Vicia faba with respect to the cell cycle response, mitotic index, chromosome aberrations and nucleic acids content. The root of young seedlings of V. faba and adventitious roots of A. cepa were treated with the following concentrations : 25%, 50%, 75% and 100% of the recommended dose (3.75 g/l) for 4, 8, 12, 24 h. The results indicated that atrazine herbicide reduced the mitotic division in both plants compared to the respective control. Mitotic index values were progressively decreased with increased the concentration and treatment time. In V. faba, the treatment with the concentration of 100% for each treatment time (4, 8, 12, 24 h) was toxic, but in A. cepa, the same concentration with 24 h was only toxic. The percentage of the reduction in MI values in V. faba was higher than that in A. cepa. Also, it has been clearly observed that the inhibition of mitotic division was associated with reduction in DNA and RNA contents in both treated plants root tips. This may point out that the inhibition of mitotic activity is due to a deficiency of DNA in the nucleus. The increased percentage of prophase in both plants was accompanied by decreased percentages of the other mitotic phase. The total percentage of aberrations increased with the increasing the concentration of atrazine herbicide and the period of treatment. The total percentage of aberrations in A. cepa was higher than that in V. faba for each treatment. Different abnormal mitotic figures were observed in all mitotic phases. Such types of abnormalities were stickiness, lagging, C-mitosis, bridges, irregular prophase, unequal distribution, fragments and a few cells with micronucleus at interphase stage.
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  • Maria Suely Pagliarini, Patrícia Matias De Freitas, Luiz Albert ...
    2000 Volume 65 Issue 3 Pages 289-294
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Cytogenetic studies carried out over a period of 2 consecutive years on a native still unidentified Brazilian accession of Paspalum (BRA-014176) revealed a meiotic mutation causing chromosome stickiness in microsporogenesis. In all inflorescences collected in both years, meiosis was normal until diakinesis. Chromosome stickiness became evident from metaphase I, when the chromosomes appeared as a dense cluster. Chromosome bridges of different thickness were observed from anaphase I to the microspore stage. In the microspores, the nucleus became pycnotic and in the pollen grain the chromatin suffered degeneration causing pollen steritlity.
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  • Soheir M. Amer, Fawzia A. E. Aly, Souria M. Donya
    2000 Volume 65 Issue 3 Pages 295-303
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    In the present studies, chromosome aberrations in splenocytes, spermatocytes and sister-chromatid exchange in bone marrow cells of the mouse were used as cytogenetic end points in genetic risk assessment of DDVP. Two routes of treatment were conducted using male swiss mice. Oral treatment by gavage for 3 successive days with 14.5 mg DDVP kg-1 body wt. and feeding mice for one, two and three months with Vicia faba seeds treated with 12 mg kg-1 DDVP and stored for 13, 26 and 39 weeks. Oral treatment by gavage with DDVP induced a dose-dependent increase in the percentage of chromosome aberrations in somatic and germ cells. It reached 17.50% (P<0.01) and 11.77% (P<0.01) in splenocyte and spermatocyte cells, respectively after treatment with 3×14.5 mg DDVP kg-1 body wt. The percentage of the induced chromosomal aberrations in somatic and germ cells increased by increasing the period of feeding with the stored seeds. DDVP induced its maximum effect on the induction of chromosomal aberrations in splenocytes and spermatocytes after feeding for 3 months with the seeds stored for 26 weeks. Its percentage reached 15.40% and 11.94% in splenocytes and spermatocytes respectively compared with 28.90% and 19.10% in splenocytes and spermatocytes respectively after i.p. injection with the positive control. The main type of aberrations in splenocytes was fragments and/or chromatid breaks. Gaps, Robertsonian translocations and tetraploid cells were observed in a lower percentage. Separation of chromosomes was the dominant type in spermatocytes. Both autosomal and X, Y univalents were observed, however, X, Y univalents were more frequent. Feeding mice with Vicia faba seeds treated with DDVP and stored for different periods of time had a weak effect on SCE's. The presented studies indicate that, the organophosphorous insecticide DDVP and its residues in stored Vicia faba seeds are genotoxic in the different kinds of cells analyzed.
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  • D. R. Malaviya, R. S. Shukla
    2000 Volume 65 Issue 3 Pages 305-311
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The karyotype of 20 cultivated varieties of lentil and 3 wild species revealed a good deal of structural variations. The chromosomal length ranged from 4.58 to 7.50 μm in L. orientalis, 3.86 to 6.11 μm in L. nigricans and 3.81 to 8.37 μm in L. montbrettii. The karyotype of L. montbrettii was assymetrical. Secondary constriction was noticed in the longest chromosome of the L. montbrettii and L. orientalis whereas it was present on the 3rd pair in L. nigricans. Total chromatin length. was 44.5 μm in L. orientalis, 34.64 μm in L. nigricans and 39.64 μm in L. montbrettii. Out of 20 genetic stocks of lentil most possessed 4-7 chromosomes with submedian centromere. In some varieties like L 3991, 74 TA 9/ILL 15 and LC 112, 3 to 4 pairs of chromosomes possessed median centromere. The size difference between the shortest and the longest chromosomes in most of the strains was less than 2 μm. Among different varieties “J” shape submetacentric chromosomes outnumbered the “V” shape metacentric chromosomes. Submetacentric chromosomes approaching acrocentric condition was found in few varieties like WYR 1811, 74 TA 276/ILL 262, 75 KT 36261/ILL 553 and Pant L 639. Most of the exotic lentil accessions possessed 0-1 metacentric and 6-7 submetacentric chromosomes and indigenous lines possessed 2-5 submetacentric and 2-4 metacentric chromosomes. Most of the karyotypes are symmetrical but a tendency towards evolution of asymmetrical is very much apparent within the species as also revealed by T. F. Meiosis in the majority of the cultivars under study showed near normal chromosomal pairing, except infrequent occurrence of univalents and multivalents. The average chiasmata frequency per bivalent was found to range from 0.8 to 1.8 in different cultivars. The exotic macrosperma cultivars in general possessed lesser chiasmata per bivalent indicating them as genetically advanced. The number of rod bivalents outnumbered the ring bivalents in all the wild species.
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  • Karima Mahrous, Sahar Ahmed
    2000 Volume 65 Issue 3 Pages 313-317
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Fragile sites expression induced by 25 μg/ml and 50μg/ml bromodeoxyuridine (BrdU) were studied in lymphocyte culture of 15 healthy Egyptian water buffalo (9 females and 6 males). In each animal, 100 metaphases were examined, the cells were scored for chromosome number and types of structural abnormalities. A site showing a gap or break was defined as fragile and reexamined after G-banding to identify the fragile site involved. The results showed significant difference (p<0.01) between 2 different doses of BrdU in the total aberrant cells and total structural abnormalities [20.5±3.9%, 42.6±3.5% (25μg/ml BrdU) and 26.9±6.4%, 55.9±10.9% (50 μg/ml BrdU), respectively]. A significant decrease in mitotic index in the treated culture was observed in respect to control culture. The difference between females and males was found to be significant in the total aberrant cells and total structural abnormalities in dose 50 μg/ml BrdU [44.2±3.2%, 40.2±2.4% and 63.3±5.6%, 44.7±5.8%, respectively]. Our results indicated that the common fragile sites are chromosome bands 2p13, 2q21, and 5q21. This is the first report of BrdU-inducible fragile sites in the genome of buffalo.
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  • Sahar Ahmed, Hala El-Miniawey
    2000 Volume 65 Issue 3 Pages 319-324
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Cytokinesis-block micronucleus method was used to obtain a standardized quantitative assay for spontanous micronuclei in buffalo lymphocytes, as first report. Blood lymphocytes of buffalo from a clean environmental area were cultured to study the effect of different concentrations of cytochalasin B (cyt-B) on the frequencies of mononucleated, binucleated and polynucleated cells. The result showed that the optimal concentration of cyt-B to obtain the highest frequency of binucleated cells was 4μg/ml (126.8±17.0/1000 cells). The micronuclei (MN) frequency varied from 9 to 22 with a mean value of 13.5 ±2.9/1000 cells. A comparative study between the MN formation in buffalo lymphocytes from clean and polluted environmental areas revealed that the animals exposed to industrial emission of heavy metals (chromium, copper, zinc, cadmium, lead) showed a significant increase in MN formation 44.1±2.0/1000 cells compared to 13.5±2.9/1000 cells in buffalo from clean environmental area. Based on our results, cyt B-method can be applied as a reliable, simple and inexpensive method to assess mutagenic factors and hygienic level of environmental surroundings in buffalo.
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  • Mikako Ito, Nobuko Ohmido, Yukio Akiyama, Kiichi Fukui
    2000 Volume 65 Issue 3 Pages 325-331
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    Arabidopsis thaliana L. has 10 chromosomes that are small and similar in morphology. Molecular cytogenetics and image analyses were applied to characterize the somatic chromosomes. Prometaphase chromosomes were quantitatively analyzed based on their patterns of condensation, because they show a prominent uneven condensation along the chromosomes. The total length of the haploid prometaphase chromosomes is 16.5 μm, which is about 1.8 times the size of the metaphase chromosomes. We also detected the 45S (18S-5.8S-25S) and 5S rDNA loci by fluorescence in situ hybridization (FISH) and determined their locations on the chromosomes by the imaging methods. As a result, a quantitative chromosome map based on the condensation pattern was developed for the first time in Arabidopsis with the locations of rDNAs by using imaging methods. It is now possible to localize genes precisely on this map.
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  • Lanzhuang Chen, Liming Guan, Akio Kojima, Taiji Adachi
    2000 Volume 65 Issue 3 Pages 333-341
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    To clarify the mechanisms of aposporous embryo sac initial cell (AIC) appearance and apomictic embryo sac formation, several apomictic and obligately sexual varieties of bahia grass (Paspalum notatum) were studied cytological and quantitatively. Over 300 young buds from every variety were treated by clearing fluid (Herr 1982) and observed with nomarski differential interference-contrast optics. The observations revealed that, there was no cytological difference between sexual and apomicts up to megasporogenesis. After megasporogenesis, however, the megaspore usually degenerated and in final, disappeared in the apomicts in contradistinction to that in sexual to form 8-nucleate embryo sac. At the same time, AIC, which is originated from nucellar tissue around the megaspore, appeared with a sharp knife shape, and inserted the space that the degenerated megaspore left. When the ovary length was measured and used as an index, it is understood that the ovules of facultative apomicts usually contain several AICs, and the numbers increased as the ovary grew before anthesis. AIC appearance was different event from obligate sexual one, so it could be considered as a related candidate with apomixis gene expression. Therefore, the results of this study will be used to provide the information on isolation of apomixis gene from apomictic varieties.
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  • Ki-Su Lee, Kanji Ono
    2000 Volume 65 Issue 3 Pages 343-349
    Published: September 25, 2000
    Released on J-STAGE: November 09, 2009
    JOURNAL FREE ACCESS
    The process of plant regeneration from cultured A. fistulosum cv. Fresh cells was investigated morphologically and histologically. Somatic embryogenesis was observed in one cell line (Yline) when cells maintained by suspension culture in liquid MS medium containing 0.5 mg/1 2, 4-D were transferred into 2, 4-D-free medium. Two somatic embryogenesis pathways were identified in Yline cells. Pathway-I was the usual monocot somatic embryogenesis type, while pathway-II was unusual, in that the development of somatic embryogenesis proceeded via a large cell cluster-like proembryo. Another line of cells (W-line) did not show any indications of morphogenesis when cultured under the same conditions as Y-line cells. This is the first report of the existence of two pathways for somatic embryogenesis in Allium species.
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