CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 65 , Issue 1
Showing 1-16 articles out of 16 articles from the selected issue
  • F. Ahmad, A. Comeau, Q. Chen, J. Collin, C. A. St-Pierre
    2000 Volume 65 Issue 1 Pages 1-6
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    Fluorescent in situ hybridization (FISH) was utilized to monitor the level of ionizing radiation (60Co source) in their ability to cause intra-and intergeneric chromosomal aberrations in triticale seeds. Seeds were irradiated with 0, 20, 50, 100, 200, 300, 400, 500 and 1000 Gy doses. The root growth of irradiated seeds was greatly inhibited at 200 Gy and above. Various types of aberrations including wheat-rye, wheat-wheat, rye-rye, wheat-rye-wheat, rye-wheat-rye translocations and acentric fragments with or without translocations were observed. There was a consistent increase in proportion of aberrations per cell with an increase in radiation dose. It was concluded that for an optimal level of chromosomal translocation and least number of acentric fragments, a 20 Gy dose was quite sufficient for inducing a desirable level of wheat-rye chromosomal translocations. The excellent efficiency and importance of utilizing FISH in such studies of alien-introgression via chromosomal translocations are discussed.
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  • J. C. De Luca, L. Zufriategui, M. V. Ripoli, G. Giovambattista, F. V. ...
    2000 Volume 65 Issue 1 Pages 7-11
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    The “Saavedreño” Creole cattle was established at the Saavedra Experimental Station (Santa Cruz de la Sierra, Bolivia) in the seventies' aiming to obtain a dairy breed adapted to humid tropical environments. The relationship between the occurrence of the 1/29 translocation and subfertility or infertility is well known. On the other hand, the analysis of the Y chromosome morphology is useful to determine the possible introgression with Bos indicus. As the incidence of 1/29 translocation and Y-chromosome morphology has not been previously studied in the “Saavedrerio” Creole cattle, cytogenetic studies were performed in 40 bulls from different origin and 47 dams. Results obtained demonstrated a low frequency of 1/29 translocation (1.15%) in the animals and the presence of an acrocentric and submetacentric Y chromosome morphology.
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  • M. Pal, D. Ohri, G. V. Subrahmanyam
    2000 Volume 65 Issue 1 Pages 13-16
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    The chromosome number of Amaranthus tenuifolius Willd. has been found to be 2n=28 which gives a new basic number (x=14) for the genus Amaranthus; previously characterized by x=16 or x=17. The karyotype of A. tenuifolius shows distinct features and is more symmetrical than that of other 14 grain and vegetable amaranth species studied.
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  • A. Dryanova, B. Dimitrov
    2000 Volume 65 Issue 1 Pages 17-23
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    Morphogenetic response of triticale callus cultures was studied after supplement of the herbicide Stomp 330 into the regeneration nutrient medium. It is found, that the regenerative ability is not affected at the lowest herbicide concentration. However, the higher doses reduce regenerative ability at different rates depending on the genotype. Rhizogenesis is completely suppressed. The necrotic calli increased and the fresh, unorganized growing calli reduced. Numerous abnormalities are observed in the treated tissues. Considerable part of the cells, especially those, situated in intensively proliferating zones are enlarged and vacuolized. Abnormalities as chromatin pycnosis and micronuclei are observed. The frequency of these abnormalities is proportional to the herbicide concentration. It is established, that Stomp 330 exerts strong C-mitotic effect in the callus cells, which is demonstrated by high frequency of polyploid cells.
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  • Alma Gpe. Arellano-Meneses, Luz Angélica Hernández-Carb ...
    2000 Volume 65 Issue 1 Pages 25-28
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    The karyotype of Peromyscus difficilis amplus from Totalco Veracruz, Mexico is reported. The chromosomes were obtained from bone marrow cells and the classification is described. The diploid number found is 48 and the fundamental number is 66. The chromosomic formula is 2M+8ST+13T. The X chromosome is subtelocentric and the Y is telocentric. The karyotype described is different from the other subspecies reported.
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  • Praneet Damrongphol, Boonserm Poolsanguan
    2000 Volume 65 Issue 1 Pages 29-34
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    Five different peroxidase-labeled lectins, Helix pomatia agglutinin (HPA), Concanavalin A agglutinin (Con A), Ricinus communis agglutinin (RCA-I), Wheat germ agglutinin (WGA) and Ulex europaeus agglutinin (UEA-I), were used to investigate alterations of the lectin binding patterns during oocyte development of the giant freshwater prawn, Macrobrachium rosenbergii. HPA, Con A and RCA-I binding sites were detected in the cytoplasm of developing oocytes; whereas HPA, WGA and UEA-I binding sites were localized on the oocyte surfaces. Although, HPA binding to the cytoplasm of developing oocytes could be detected at all stages of development, significant differentiation of the binding occurred at vitellogenic stage. Con A or RCA-I binding to the cytoplasm was first detected at early vitellogenic stage but the patterns of binding were altered at later stage. Moreover, HPA, Con A or RCA-I was reactive to different regions of the cytoplasm and produced different types of the reaction products. Formation of new surface components at vitellogenic stage was also implicated. The oocyte surfaces began to be reactive to HPA at early vitellogenic stage and were intensely reactive to HPA, WGA and UEA-I at late vitellogenic stage. Furthermore, affinity of HPA or RCA-I to the nucleolus was also detected at late vitellogenic stage.
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  • T. V. V. Seetharami Reddi, D. Rama Mohana Rao
    2000 Volume 65 Issue 1 Pages 35-41
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    In the desynaptic plants at pachytene no single unpaired threads were noted and pairing was apparently complete. The desynaptic mutants were classified into 'medium strong' based on the number of univalents present at diakinesis. Mean number of chiasmata per bivalent was significantly less in the mutant plants when compared to normals. In the desynaptic plants, when the mean bivalent frequency was less than three, there was no clear metaphase I stage, but it was rather a metaanaphase stage. The unoriented chromosomes at metaphase I lead to highly irregular distribution of chromosomes ranging from 11 : 13 to 4 : 20 at anaphase I. Variable number of microspore formation per PMC was observed at tetrad stage. Formation of micronuclei was also observed with considerable frequency. Complete pollen and seed sterility was observed.
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  • M. G. M. Franzoni, M. A. A. Castro-Prado
    2000 Volume 65 Issue 1 Pages 43-48
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    5-Azacytidine is a cytidine analogue whose incorporation into DNA leads to DNA hypomethylation. This 5-azacytidine effect results in alterations in a variety of gene functions including cellular differentiation and gene expression. The aim of this work is to demonstrate the recombinogenic effect of 5-azacytidine. The Aspergillus nidulans master strains UT448 and UT196 were used to produce the UT448//UT196 diploid strain. Conidia of this strain were inoculated in Petri dishes containing selective medium supplemented with 40 or 100 μM 5-azacytidine. The plates were incubated for 5 days at 37°C. Mitotic segregants were isolated from the diploid colonies and phenotypes of the segregants were analyzed. 5-Azacytidine was shown to be positive in inducing somatic crossing-over in diploid cells of A. nidulans. An increase in the mitotic recombination frequencies was observed in several linkage-intervals of chromosomes I and II from UT448//UT196 diploid strain.
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  • A. B. Das, S. Mohanty, R. H. Marrs, P. Das
    2000 Volume 65 Issue 1 Pages 49-56
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    Karyotype analysis, determination of somatic chromosome number, total chromosome length and volume, cytophotometric estimation of 4C DNA content and Interphase Nuclear Volume (INV) were carried out in 6 species of Ferocactus of the family Cactaceae. Significant interspecific variations in nuclear DNA amount were noted with a constant somatic chromosome number (2n=22). The 4C DNA content varied from 7.04 pg in F. horridus to 9.20 pg in F. wislizeni. The INV varied from 330.22 μm3 in F. latispinus to 482.36 μm3 in F. wislizeni. The 4C DNA content showed a significant positive correlation with both mean chromosome volume and INV; mean chromosome volume also showed a significant correlation with mean INV. The structural alterations in the chromosomes as well as loss or addition of highly repetitive sequences in the genome suggest variations in the nuclear DNA at interspecific level during macro- and micro-evolution of the species.
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  • Marcos Antonio Loureiro, Lucia Giuliano Caetano, Ana Lúcia Dias
    2000 Volume 65 Issue 1 Pages 57-63
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    The two species of genus Crenicichla showed the same diploid number, 2n=48 chromosomes with different karyotypes. The diploid number of 48 chromosomes is proposed as a conserved characteristics through the karyotypic evolution of cichlids. The NOR, coinciding with the secondary constriction, was detected on the short arm of the first metacentric chromosome pair in two species. The treatment by chromomycin fluorochrome coincided with the NOR and through the DAPI fluorochrome technique it was detected no marking, being negative on the secondary constriction. The pattern of constitutive heterochromatin was very similar among these species, being observed preferentially in centromeric regions, as well as on the secondary constriction.
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  • M. S. Hassanane, B. P. Chowdhary, I. Gustavsson
    2000 Volume 65 Issue 1 Pages 65-69
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    We are successfully succeeded in producing 2 painting probes from the bovine Y chromosome using chromosome microdissection and DOP-PCR techniques. We are separately microdissected 5 to 6 copies from both the whole Y bovine chromosome and the q arm of the Y bovine chromosome. We amplify these microdissected DNA fragments through DOP-PCR. Fluorescent in situ hybridization technique (FISH) with these probes on a metaphase spread from a normal bovine lymophcyte cultures from cattle, buffalo, sheep and goat was applied.
    Surprisingly that both of the two probes were hybridized only to the bovine Y chromosome without any background or cross hybridization to any other chromosome especially the X chromosome. A similar hybridization signal was also observed when these probes were tested in river buffalo. In contrast, no signal was observed when these probes were tested on both sheep and goat metaphase spreads.
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  • Lyderson Facio Viccini, Carlos Roberto de Carvalho
    2000 Volume 65 Issue 1 Pages 71-73
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    Maize chromosome deficiency induced by irradiated pollen was characterized by image analysis. Chromosome measurements were obtained by the difference of chromosomal area density and that of the background. This methodology allows to make up precisely the deficiency length.
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  • N. M. George
    2000 Volume 65 Issue 1 Pages 75-82
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    The three heavy metals Pb, Hg and Cd were examined for the induction of meiotic abnormalities and changes in the M2 seed storage protein banding patterns of Vicia faba plants. The used metal nitrate solutions induced a wide range of meiotic abnormalities. The most abundant of them were stickiness, break, lagging, bridges and disturbed phases. At the level of M2 seed storage protein, the 3 tested metals caused changes in the protein banding patterns especially at the high molecular weight regions. The results showed that lead and mercury have more mutagenic potentialities than cadmium.
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  • Eyyüp Rencüzogullari, Mehmet Topaktas
    2000 Volume 65 Issue 1 Pages 83-92
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    The aim of this study was to investigate the ability of the mixtures of carbosulfan (C) (the effective ingredient of “marshal”, an insecticide/nematocide) and ethyl carbamate (EC) (carcinogen) and also the mixtures of carbosulfan and ethyl methanesulfonate (EMS) (mutagen) to induce the chromosomal aberrations (CA) in human peripheral lymphocytes and to investigate whether the test substances as a mixture had any synergistic effect. All the mixtures of the test substances increased the formation of chromosomal aberrations at all the concentrations and treatment times compared to the control groups. The combination of carbosulfan and EC synergistically increased the formation of CA, at the same concentrations of both carbosulfan and EC at 48 h treatment time. The combination of carbosulfan and EMS also synergistically increased the formation of CA especially at the high concentrations for 48 h treatment times.
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  • Rita M. P. Avancini, Shirlei M. Recco-Pimentel, Angelo P. Prado
    2000 Volume 65 Issue 1 Pages 93-96
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    The karyotype of Labidura riparia from Brazil is 2n=5A+XY for males and 2n=5A+XX for females. The chromosomes can be grouped into 3 large and 3 small pairs, the latter including the sex chromosomes. The Y chromosome is entirely C-band positive and remains heteropycnotic during most of the division cycle. The X chromosome, which is longer than the Y chromosome, presents no C-banding. The longest chromosome of the complement has very noticeable Cbands at one of its terminal. Only one nucleolus was seen in the preparations examined. These results on the general chromosomal morphology are very similar to the karyotype described for L. riparia in the USA. The most significant similarity is that chromosome number 1 is about 20% longer than chromosome 2, a feature not observed in the karyotypes of L. riparia from other regions of the world. In addition, the difference in size between the chromosomes X and Y of Brazilian and US L. riparia is not as large as that for other populations.
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  • Aveliano Fernández, Maria M. Arbo
    2000 Volume 65 Issue 1 Pages 97-102
    Published: March 25, 2000
    Released: November 09, 2009
    JOURNAL FREE ACCESS
    We hybridized 2 octoploid species (2n=8x=40) T. aureliis and T. cuneiformis and one hexaploid species (2n=6x=30), T. orientalis. One octoploid (2n=8x=40) and 2 heptaploid (2n=7x=35) hybrids were obtained. The hybrids were studied cytologically to determine their genomic relationships. Meiotic behavior in the T aureliis×T. cuneiformis hybrid was very irregular, with numerous laggard chromosomes and bridges in AI and AII. Mean pairing relationships were 10.10 I, 13.80 II, 0.53 III and 0.13 IV. All cells of T. aureliis×T. orientalis had 5 I+15 II, while T. cuneiformis×T. orientalis presented irregular meiosis, with mean pairing relationships of 4.86 I, 14.86 II and 0.13 III. The genome constitution of T. aurelii is AaAaAoAoBBBoBo and of T. orientalis is AoAoBBBoBo. On the basis of the chromosome associations in the hybrids, we propose the genomic formula AcuAcuAoAoBBBoBo for T. cuneiformis. The 3 genomes of T. orientalis are similar to 3 of the 4 genomes of T. aureliis and T. cuneiformis. The 2 latter species show also 3 common genomes and the fourth one is homoeologous.
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