CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 55 , Issue 1
Showing 1-25 articles out of 25 articles from the selected issue
  • H. U. Anaso, J. O. Uzo
    1990 Volume 55 Issue 1 Pages 1-14
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Preliminary investigations were carried out on cytomorphology, proximate chemical analysis and crossability relationships of three members of the genus Solanum both classified as S. incanum, with a view to establishing the genetic basis of their taxonomic relationships. Results from these investigations revealed variations in morphological characters, behaviour of chromosomes, proximate chemical composition and crossability relationships.
    With basic chromosome numbers of n=24 in both thorny and non thorny S. incanum (Plates 1 and 2) and preferential pairing of chromosomes, it is quite clear that these two wild types are not the same as the diploid West African S. incanum whose genomic number was n=12 and in which pairing was allosyndetic.
    Chemical composition of the two wild forms of S. incanum showed 71.59 per cent for the thorny and 73.58 per cent moisture for the non thorny S. incanum as against 85.56 per cent moisture content in the diploid cultivated S. incanum. Also protein and lipid contents of the wild tetraploid species were 5.30, 5.25 (for protein) and 7.03 and 7.00 per cent respectively as against 0.83 per cent reported in the diploid S. incanum.
    There was high cross-compatibility between the wild tetraploid thorny and wild tetraploid non thorny S. incanum but strong pistil pollen incompatibility between the two wild forms and the diploid cultivated S. incanum. The similarity in some behaviour of chromosomes between the wild tetraploid forms and the cultivated diploid species was probably due to the fact that the wild tetraploid forms of Solanum incanum were amphidiploids.
    It is suggested that the non thorny wild tetraploid S. incanum (Fig. 2) is a direct derivative of the thorny wild tetraploid S. incanum (Fig. 1), since both are similar morphologically, in behaviour of their chromosomes and chemical composition of their berries. It is also suggested that the non thorny tetraploid S. incanum is a botanical variety of the thorny tetraploid type and that the absence of thorns in the former was as a result of point mutation. If either the thorny wild tetraploid S. incanum or its non thorny derivative was truly the ancestor of the diploid S. incanum, then retrogressive evolution had taken place. But the trends in angiosperm evolution is for the lower genomic form to give rise to the higher genomic form.
    It is therefore concluded that the wild tetraploid S. incanum is not related to the cultivated diploid S. incanum. The name spinosum is suggested for the wild thorny S. incanum while incanum is reserved for the cultivated form of Solanum incanum. The non thorny wild derivative is a botanical variety of the thorny wild tetraploid form.
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  • M. Ahmad, T. K. Ghosh, A. Moitra, J. S. Datta Munshi
    1990 Volume 55 Issue 1 Pages 15-19
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The morphological and morphometric studies of the blood cells of an Indian air-breathing fish, Monopterus cuchia have been made using scanning electron microscope. The large elliptical erythrocytes (9.9μm×6.9μm) have relatively smooth surface. Clone cells arise within the erythrocytes and have been found to release red cell fragments, the “schistocytes” with spinous projections, which later on take the form of normal erythrocytes. Heteromorphogenic division of the red blood cells has also been observed. Among leucocytes, the mature granulocyte cells appear to be spherical with smooth surface. The granulocytes show multiple pseudopodial projections and are quite different from the erythrocytes. Several pits and protrusions are seen on their surfaces, giving a sieve like appearance. Morphometric measurements of different cell types have been done.
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  • Claudio Oliveira, Lurdes Foresti de Almeida Toledo, Silvio de Almeida ...
    1990 Volume 55 Issue 1 Pages 21-26
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Three local geographically isolated populations of C. nattereri from Brazil were analyzed. A different diploid number was detected in each sample, i.e., 2n=40 (Bonito river), 2n=42 (Biguá river), and 2n=44 (Tinguá river). Analysis of Nucleolus Organizer Regions showed that the Rio de Janeiro samples have one chromosome pair with NOR, while the Sao Paulo sample has two. In general, the NORs are C-band positive. Analysis of constitutive heterochromatin distribution showed some similarities between two of the populations. The different chromosome formulae identified permitted the characterization of the occurrence of three cytotypes for C. nattereri, suggesting that these cytotypes may actually be different species.
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  • H. N. Murthy
    1990 Volume 55 Issue 1 Pages 27-29
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Guizotia bidentoides was first described by Oliver and Hiern (1877) in the Flora of Tropical Africa. Hoffmann (1889) transferred this taxon to genus Bidens as Bidens pinnatipartita (Hoffm.) Wild. Baagøe (1974), based on morphological studies, suggested to retain this species in the genus Bidens. Cytological investigation of G. bidentoides reveals that this species is consisting of 2n=48 chromosomes and karyotype is asymmetrical. Meiotic studies showed twenty four bivalents at diakinesis. Thus, transfer of Guizotia bidentoides from genus Guizotia to Bidens (Baagøe 1974) on morphological ground is fully corroborated by present cytological evidences.
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  • M. J. Olszewska, J. Maszewski, A. Bilecka
    1990 Volume 55 Issue 1 Pages 31-35
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Using fiber autoradiography, replicon sizes and DNA replication fork rates were studied in 6 diploid angiosperm annual species with different 2C DNA values and S phase durations (Ts). The only correlations were found between Ts and Rs/Ts ratios (positive correlation, p=0.001) and between 2C DNA content and the rate of fork movement (negative correlation, p=0.05). The observations raise the possibility of a connection between the mechanisms involved in DNA chain elongation and the amount of repetitive sequences and between Ts and the functional arrangements of replicons.
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  • N. K. Rao, E. H. Roberts
    1990 Volume 55 Issue 1 Pages 37-42
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Chromatid-type aberrations were predominant at all levels of viability in the primary roots derived from lettuce seeds stored at moisture contents from 8.1% to 18.1%. In seeds stored at lower moisture contents (3.3 and 5.5%), although chromatid aberrations were predominant initially, there was a relative increase in the chromosome-type aberrations with loss of viability. The implications of these results are discussed in relation to the mechanism of production of chromosomal aberrations.
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  • B. R. Tyagi, Ratna Dubey
    1990 Volume 55 Issue 1 Pages 43-50
    Published: March 25, 1990
    Released: March 19, 2009
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    Morphology of the pachytene chromosomes of Artemisia annua (2n=18) has been studied in detail. In all chromosomes the heterochromatin is clustered around the centromere. On the basis of total length the chromosomes are numbered from 1 to 9, the last being the shortest of the complement. The short arm of chromosome 3 is associated with the nucleolus. Each of the nine pachytene bivalents has been identified by its distinctive morphological features such as relative length, position of centromere, symmetry of heterochromatic parts and presence of characteristic chromomeres.
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  • An aneuploid of Plantago lagopus L. for a telocentric microchromosome
    Manoj K. Dhar, A. K. Koul, A. Langer
    1990 Volume 55 Issue 1 Pages 51-56
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    In the progeny of a cross between di- and trisomic plants of Plantago lagopus, one offspring had the full complement of 12 and a small additional chromosome. The latter is distinct on account of its very small size and terminal centromere. To distinguish it from rest it has been called microchromosome. It shows affinity with one of the two nucleolar chromosomes of the standard complement and keeps attached to the nucleolus during prophase. The microchromosome gets transmitted through male as well as female sex tracks. In the progeny raised by selfing the m plus plants, a few offsprings with two m chromosomes have been recovered.
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  • J. Christopher, Benny Jacob
    1990 Volume 55 Issue 1 Pages 57-60
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Detailed cytological investigation has been made on Coix lacryma-Jobi var. ma-yuen, a soft-shelled cultivated taxon, collected from North East India. The count of 2n=30 for this species is the first hexaploid record for the genus. The previous reports have all been di-tetra or octoploids with a few aneuploids. Meiosis has been found to be somewhat irregular with a few multivalents and univalents along with bivalents in all the PMCs. The karyotype is unspecialized belonging to 1A category and the chromosomes are similar to the other varieties of C. lacryma-Jobi in size and morphology. The origin of this cyto-type is only speculative and the evidence indicates that it is probably a hybrid.
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  • H. S. Balyan, George Fedak
    1990 Volume 55 Issue 1 Pages 61-64
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    By crossing an amphiploid (T. timopheevii×H. bogdanii)2 as maternal parent with another amphiploid (H. californicum×T. aestivum) four hybrid plants were recovered at a frequency of 2.4% of the pollinated florets. The meiotic analysis of the data revealed a mean chiasmata frequency per cell in four hybrid combinations ranging from 7.61 to 8.63. Average chromosome associations of 6.12 bivalents, 0.33 trivalents and 0.007 quadrivalents per cell were observed at metaphase I. The lower than expected bivalent frequency in the septavalent hybrid (2n=7x=49, AABDGHH) was attributed to the suppression of meiotic chromosome pairing by H. californicum.
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  • H. S. Balyan, George Fedak
    1990 Volume 55 Issue 1 Pages 65-69
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Two hybrids between an amphiploid (Triticum timopheevii×Hordeum bogdanii)2 and two cultivars of triticale (×Triticosecale Wittmack), Currency and Welsh, were produced at frequencies of 16.7 and 1.7% of pollinated florets. The mean chiasmata frequency per cell in two hybrid combinations ranged from 13.85 to 14.42. In hybrids, chromosome associations of up to eight bivalents plus the small frequencies of multivalents including trivalents, quadrivalents and pentavalents were observed at metaphase I. The bivalent frequencies in excess of seven and low frequencies of multivalents were attributed to pairing between A, B, G and H genome chromosomes.
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  • A. B. Sapre, Anjali S. Naik
    1990 Volume 55 Issue 1 Pages 71-77
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Mixoploid plant showing a range of aneuploid PMCs from nullisomic (2n-2, 2n=18) to tetrasomic (2n+2, 2n=22) constitutions was isolated from a population of Coix gigantea. While majority of the PMCs were diploid carrying 2n=20 chromosomes, nearly 24% PMCs in some male racemes showed typical aneuploid chromosome configurations viz., 9II in nullisomics (2n=18), 9II+1I in monosomics (2n=19), 9II+1III or 10II+1I in trisomics (2n=21) and 11II or 9II+1IV in tetrasomics (2n=22). The chromosome configurational regularity among the aneuploid PMCs indicated that 2n-1 (2n=19) and 2n+1 (2n=21) constitutions probably arose through nondisjunction during one of the premeiotic mitoses in some sporogenous cells. Although difficult to explain the origin of PMCs with 2n-2 (2n=18) and 2n+2 (2n=22) constitutions, somatic pairing followed by nondisjunction during one of the premeiotic mitoses might lead to such situations.
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  • Enrique Y. Suárez, Laura Bullrich
    1990 Volume 55 Issue 1 Pages 79-86
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Magnif 41, a bread wheat cultivar shows very abnormal microsporogenesis, apparently as a consequence of spindle disturbances giving a chaotic picture at the tetrad stage producing pollen grains of different size and frequently showing the presence of micronuclei. Female meiosis seems also to be affected but to a lesser extent than that observed on the male side. High aneuploidy frequency is observed in this cultivar, some of them with very atypical chromosome number or structure. Apparently mitotic spindles are not affected, however in the archesporial cells some disturbances have been detected. The origin of this behaviour seems to be a chromosome mutation inherited like a recessive factor, because it has also been observed in some off-type plants of Sinvalocho M. A., ancestor of this cultivar.
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  • O. P. Chaurasia, S. P. Sinha
    1990 Volume 55 Issue 1 Pages 87-90
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Muriate of potash (potassium chloride), when administered orally at the rate of 500 mg per mouse (Mus musculus) per day for eight days, was able to induce a six-fold increase in the rate of chromosomal abnormalities in the bone-marrow cells. Gross type abnormalities like stickiness, clumping and pulverisation, etc., and individual types like chromatid breaks, gaps, centric fusion and deletions were observed. The breaks were randomly distributed in respect to both chromosome number and length (region).
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  • Cytological effects of isoproturon on the root meristem cells of Allium cepa
    L. K. S. Chauhan, V. Sundararaman
    1990 Volume 55 Issue 1 Pages 91-98
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Isoproturon, a substituted urea herbicide, was tested to study the possible effects on the root growth, macromolecular biosynthesis, and mitoses in the root meristem cells of Allium cepa. The compound exerted dose-dependent root growth retardation. Inhibition of macromolecular biosynthesis as observed with the treatment of isoproturon possibly led to the mitodepression. Induction of various cytological abnormalities suggests that isoproturon is highly turbogenic (spindle poison) rather than clastogenic. Moreover, induction of chromosome breaks in addition to various mitotic abnormalities may lead to mutagenic events.
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  • Ultrastructural effects of isoproturon on the root meristem cells of Allium cepa
    L. K. S. Chauhan, V. Sundararaman
    1990 Volume 55 Issue 1 Pages 99-105
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Electron microscopic studies were conducted on the root meristem cells of Allium cepa to find out the effect of isoproturon on the organelles involved in cell division. The action of isoproturon was apparently observed on the nucleus and microtubules of these cells. Electron microscopic observations are consistent with that of light microscopic studies showing various mitotic aberrations. These observations indicate effect of isoproturon on microtubular function, though further evidence is required to explain whether microtubular protein polymerization is the mechanism of such alterations.
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  • B. N. Susheelamma, Jalaja S. Kumar, S. B. Dandin, M. S. Jolly, K. Seng ...
    1990 Volume 55 Issue 1 Pages 107-114
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Karyotype studies of ten exotic cultivars namely, Kosen, Kokuso-13, Kokuso-21, Kokuso-27, Roso and Rokokuyso belonging to Morus latifolia Poir., Kenmochi, Mizusawa and Ichihei belonging to Morus bombycis Koidz. and Chinapeking belonging to M. alba L. were reported for the first time. Of the ten cultivars, five are diploids (2n=28), two are triploids (2n=3x=42) and remaining three are aneuploids (2n=28+2). Chromosomes are generally small with an average length of 1.16μ and length ranges from 0.62μ to 1.70μ in all the cultivars studied. Relative length ranges from 96 to 131μ. In most of the cases, complement consists of only two types of chromosomes with median and submedian centromeres resulting in bimodal karyotypes. As a whole, frequency of median chromosomes is more than submedian ones. Of the ten strains, two strains namely Kokuso-13 and Mizusawa bear satellite chromosomes. Morphological variation and evolution of taxa were attributed to structural changes in the karyotype and an attempt has been made to study the phylogenetic relationship among the varieties of each species based on their karyotype. Vegetative propogation seems to have played a major role in maintaining the taxa at different ploidy level.
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  • Jeanne Zoundjihekpon, Sadi Essad, Bakary Toure
    1990 Volume 55 Issue 1 Pages 115-120
    Published: March 25, 1990
    Released: March 19, 2009
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    Des études caryologiques ont permis de déterminer le nombre chromosomique 2n de vingt échantillons du complexe Dioscorea cayenensis-rotundata. Tous les echantillons observés ont le nombre de base x=10. On a ainsi observé onze tétraploïdes (2n=40), sept hexaploïdes (2n=60) et deux octoploïdes (2n=80). Dans les dix groupes variétaux analysés, neuf ont le même niveau de ploïdie. Le groupe variétal Gnan présente deux niveaux de ploïdie: 4x pour I'échantillon béninois et 6x pour les échantillons ivoiriens. Les résultats obtenus sont en accord avec les hypothèses polyphylétiques de l'origine du complexe Dioscorea cayenensis-rotundata. Mais, contrairement à ce qu'on avait tendance à affirmer, it n'y a pas de localisation préférentielle des tétraploïdes au Nord de la Côte d'lvoire, ni des hexaploïdes au Sud.
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  • Song Ping
    1990 Volume 55 Issue 1 Pages 121-124
    Published: March 25, 1990
    Released: March 19, 2009
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    The karyotype of Gossypium bickii Prokh., a wild diploid species originated in Australia, was analysed in this article. The result showed that the karyotype formula of G. bickii was 2n=2x=26=20 m+6 sm and had no satellite chromosome. This further proved the taxonomical position of G. bickii as the only species of G genome in Gossypium.
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  • O. Azzioui, J. Moret, M. Guern
    1990 Volume 55 Issue 1 Pages 125-134
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    A study of C-bands on Giemsa stained chromosomes was carried out on Ornithogalum species from Morocco. Results concerning two closely akin European taxa are also given. The heterochromatic profiles of these species are not very rich. Certain populations of O. kochii have shown a chromosomal translocation. Based on these results, the relationships between the taxa and biogeographical implications are discussed.
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  • Madhumita Joardar, Archana Sharma
    1990 Volume 55 Issue 1 Pages 135-139
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Manganese, a metal of the first group of transitional elements is a known essential element for nutrition in both plant and animal systems. Information on the effects of Mn on cell division and chromosome, particularly in vivo is relatively meagre. The present experiment with both plant and animal systems indicated its toxicity. Mn2+ induced statistically significant number of breaks in both the systems in vivo.
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  • Ta-pen Wu
    1990 Volume 55 Issue 1 Pages 141-151
    Published: March 25, 1990
    Released: March 19, 2009
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    Comparing the important morphological characteristics between Sorghum macrospermum a single species accommodated in Chaetosorghum and S. bicolor a 20-chromosome Eu-sorghum species, the former was found to be more advanced than the latter. Detailed analysis of the karyotype of S. macrospermum at pachytene stage shows that the karyotype of this species is essentially similar to that of S. bicolor, but the former species has forty somatic chromosomes which is twice chromosome number of the latter species. The meiotic behavior of S. macrospermum is fairly regular with only a few quadrivalents and followed by normal fertility. Based on these morphological and cytological data, the author speculates that the Chaetosorghum is probably a segmental allopolyploid which arose as a result of the doubling of chromosomes of a natural hybrid between two putative 20-chromosome Eu-sorghum species whose chromosome complements are closely related but not identical.
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  • B. R. Tyagi
    1990 Volume 55 Issue 1 Pages 153-159
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Breeding behavior of an autotriploid Hyoscyamus muticus (3n=3x=42) was determined by studying the meiotic chromosome constitution of the 122 plants from 3n-selfed and 2n×3n and 3n×2n crosses. Of these, 109 (89.3%) were diploids with 28 chromosomes and 13 (10.7%) were aneuploids with 29 to 32 chromosomes. The recovery of only 32 as the highest chromosome number in the progeny suggested that the maximum number of extra chromosomes tolerated by this species is four. The aneuploids with up to four extra chromosomes were obtained only in the progeny of 3n-selfed and 3n×2n cross indicating female transmission of the extra chromosomes. Of the 13 aneuploids in the progeny of autotriploid, six plants with 29 chromosomes, four plants with 30 chromosomes, one plant with 31 chromosomes and two plants with 32 chromosomes were positively identified as single primary trisomics (2n+1), double primary trisomics (2n+1+1), triple primary trisomic (2n+1+1+1) and quadruple primary trisomics (2n+1+1+1+1), respectively, on the basis of their meiotic chromosome pairing behavior. The 3n×2n cross produced higher percentage of single primary trisomics than did 3n-selfed.
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  • M. A. Hamoud, A. Badr, Z. Turki
    1990 Volume 55 Issue 1 Pages 161-167
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The cytological features of 10 taxa belonging to 7 species of Allium L. have been investigated. These species are A. ampeloprasum, A. arvense, A. barthianum, A. curium and A. mareoticum from section Allium of subgenus Allium, and A. blomfieldianum and A. roseum from section Molium of subgenus Allium. The cytological results revealed a basic chromosome number of x=8 in all the investigated taxa. Diploid chromosome number of 2n=16 has been recorded in two taxa of A. barthianum, one taxon of A. blomfieldianum and one taxon of A. roseum. The triploid number of 2n=24 has been encountered in a sample of A. roseum. In one sample of A. barthianum, however, 3 B chromosomes have been detected. Tetraploid number of 2n=32 has been recorded in the other four species. The karyotypes of A. arvense, A. barthianum, A. blomfieldianum, A. curium and A. mareoticum are described here for the first time. The cytological and taxonomic relationships of the investigated species are discussed in the text.
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  • Kuldeep Kumar Koul
    1990 Volume 55 Issue 1 Pages 169-173
    Published: March 25, 1990
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Cytomixis has been observed for the first time in a tetraploid Alopecurus arundinaceus (2n=4x=28). This phenomenon has resulted in the formation of hypo- and hyperploid cells which, however, failed to reach later stages of meiosis.
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