CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 33 , Issue 1
Showing 1-18 articles out of 18 articles from the selected issue
  • Brunetto Chiarelli
    1968 Volume 33 Issue 1 Pages 1-16
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The chromosomes of 27 animals belonging to 11 species of the genus Cercopithecus were studied.
    The number of chromosomes for the different species studied, varies from a minimum of 2n=54 to a max. of 2n=72. In individuals belonging to the same species, a different number of chromosomes has been noted.
    The morphological analysis did not reveal any clear relation between the total number of chromosomes and the number of acrocentric chromosomes.
    The total length of the caryotype measured on 20 metaphase plates, increases with the increase of the number of the chromosomes.
    On the basis of these two data I suggest the hypothesis that the variation in the number of the chromosomes of the genus Cercopithecus is originated by the reduplication of single chromosomes.
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  • B. L. Kaul
    1968 Volume 33 Issue 1 Pages 17-20
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The effect of infection with mosaic virus on the meiotic process of Datura quarcifolia has been studied. It was seen that there was complete breakdown of synapsis at diakinasis and metaphase I and 24 univalents were observed. As a consequence of presence of univalents many irregularities appeared during the later stages. There was a significant reduction in the pollen and seed fertility.
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  • II. Meiotic effects of some phenols
    Soheir M. Amer, Enaam M. Ali
    1968 Volume 33 Issue 1 Pages 21-33
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The cytological effects of some phenols which are either used as pesticides, or are the degradation or end-products of well known pesticides were tested on the meiosis of Vicia faba. The used phenols did not show much variations in the types of the induced abnormal P.M.Cs. The most abundant meiotic irregularities were: stickiness, lagging chromosomes, and anaphase bridges; less common phenomena e.g. fragmentation were also observed and discussed. P-nitrophenol was the most toxic of all the used phenols, since it produced the highest percentage at abnormal P.M.Cs. The used phenols did not effect pollen viability. More than 40, 000 P.M.Cs, and more than 50, 000 P.Gs were investigated in the present study.
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  • Aiko Sakai, Michio Shigenaga
    1968 Volume 33 Issue 1 Pages 34-45
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The course of formation of the stack of annulate lamellae was studied in spermatogonial cells of the grasshopper, Atractomorpha bedeli. A tubular body with a very compact and regular pattern occurs often in the cytoplasm (Fig. 1). Some tubules in the tubular body protrude into the cytoplasm, becoming wider in diameter (Figs. 2 and 3). Protruding tubules may fuse with each other forming a lamella (Figs. 2 and 3). As a result, many parallel cisternae with an annuli or a periodic pattern (Fig. 4) develop in the form of a stack of annulate lamellae. With the further growth of the lamellar stack the compact and regular form of the tubular body is lost (Fig. 6). The tubular body gradually becomes smaller (Figs. 7 and 8), and finally disappears when the lamellar stack has developed fully (Fig. 9).
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  • J. Venkateswarlu, Panuganti N. Rao
    1968 Volume 33 Issue 1 Pages 46-49
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Asynapsis was observed at diakinesis in the pollen mother cells of a single flower bud of Zebrina pendula Schnizl. (n=12), while the rest of the material was non-asynaptic showing rings and chains of 6, 4 or 3 chromosomes, bivalents and univalents.
    Reduced chiasma frequency, high frequency of univalents and rod bivalents and low frequency of higher associations indicate a failure of chromosome pairing or chiasma formation in the exceptional bud.
    A gene or chromosome mutation controlling chromosome pairing or chiasma formation occurring in the inflorescence primordium or in the primordium of a flower has probably caused the reduction in the chiasma frequency.
    The above and similar occurrence of asynapsis as effecting a few cells in the sporangium or one or more flowers in an inflorescence is considered to be related to the time of occurrence of the mutation.
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  • S. L. Basak, P. K. Biswas
    1968 Volume 33 Issue 1 Pages 50-53
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. In autotetraploid of jute (Corchorus olitorius L.) maximum number of PMC's were found to contain three to five quadrivalents, four quadrivalent being the modal class.
    2. The coefficient of realization of quadrivalent was found to be high (0.57).
    3. All types of quadrivalent configurations were observed. Ring (52.12%), chain (22.12%), spoon (11.79%) and figure of eight (8.84%) were predominant types of configurations.
    4. In respect to coorientation of quadrivalents, linear, convergent, parallel and indifferent types of configurations were observed.
    5. Chiasmata per chromosome in tetraploid and diploid were found to be 0.89 and 0.93 respectively.
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  • P. D. Gupta
    1968 Volume 33 Issue 1 Pages 60-68
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. In the present work, the origin and cytochemistry of both the types of yolk (fatty and compound) in the oogenesis of Locusta migratoria are discussed.
    2. The fatty yolk globules (L3 bodies), consisting of triglycerides only, are derived from the Golgi bodies (L1 bodies), consisting of phospholipids only, through an intermediate stage, the duplex Golgi bodies (L2 bodies) which contain phospholipids in their cortices and triglycerides in their medullae. In this process the thick cortex of duplex Golgi bodies becomes greatly attenuated.
    3. The compound yolk globules have their origin from the fine circumnuclear carbohydrate granules of the early oocyte which arrange themselves at the cortical ooplasm in the late stages of oogenesis, where they grow and form the compound yolk globules.
    4. The protein moiety of the compound yolk is formed under the influence of nucleolar RNA which plays an important role in protein synthesis.
    5. Cytochemically, the compound yolk consists of carbohydrates (1:2 glycol groups) and acidic proteins; it is devoid of mucopolysaccharides and glycogens.
    6. The mitochondria, throughout oogenesis, remain in the form of small granules and do not take part in yolk synthesis.
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  • Distribution of bivalents
    P. R. Sreenath, S. K. Sinha
    1968 Volume 33 Issue 1 Pages 69-72
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    In order to ascertain the cause of deviation from the expected distribution of bivalents in asynaptic maize two models were set up corresponding to two different situations: 1) differential behaviour of chromosomes within meiocytes and 2) differences in the degree of synapsis between meiocytes within a population. Analysis of published data indicated differences between groups of meiocytes rather than intracellular differences. The implications of this finding and the limitations of this method of analysis were discussed.
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  • A. J. Pritchard, R. D. Court
    1968 Volume 33 Issue 1 Pages 73-77
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Treatment of dividing cells in root tips of Vicia faba with either mimosine or the sodium salt of mimosine in aqueous solution resulted in clumping and non-division of chromosomes at metaphase. A c-mitosis sometimes resulted from treatment with relatively low concentrations. Clumped nuclei did not divide while the mimosine treatment was maintained but growth was possible in radicles of V. faba after a treatment of 24hr in a 1 per cent solution of the sodium salt.
    Mimosine also caused chromosome clumping in the root tips of Glycine javanica, Secale cereale, Allium cepa, Hordeum vulgare and Leucaena leucocephala.
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  • Shigemi Honma
    1968 Volume 33 Issue 1 Pages 78-81
    Published: March 25, 1968
    Released: March 19, 2009
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    Cytological study was made on F1 plants of an intraspecific cross of P. vulgaris. Flower buds were fixed in propiono-alcohol and the pollen-mother cells were stained with propiono-carmine.
    The meiotic behavior was normal for the parental material. A few pollen-mother cells of the F1 plant showed cells with one or two bridges per cell. This meiotic irregularity indicated that the F1 plant was heterozygous for paracentric inversions and is probably the reason why favorable recombinants have not been obtained from this intraspecific cross.
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  • L. S. O. Ene
    1968 Volume 33 Issue 1 Pages 82-93
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Four species of Iberis, I. amara, I. pectinata, I. umbellata and I. saxatilis collected from Great Britain, all over Europe and some areas in the Mediterranean (not in Europe) were studied.
    They were shown to have normal flower buds with regular ratio between the length of the large sepal which partially encloses the rest of the bud. They had abnormal flower buds as well in which the above ratio was altered considerably. The abnormal flower buds were also sterile and had some malformations affecting the reproductive parts.
    Cytological studies established chromosome counts in both normal and abnormal buds:
    I. amara 2n=14 (normal); 2n=15 (abnormal)
    I. pectinata 2n=14 (normal); 2n=15 (abnormal)
    I. umbellata 2n=18 (normal); 2n =19, 20, 22 (abnormal)
    I. saxatilis 2n=22 (normal); 2n=23, 24 (abnormal)
    Strong evidence was presented indicating that the extra chromosomes in the abnormal buds were trisomics and tetrasomics (with occasional double tetrasomics). Correlated with translocations and multiple bivalent secondary associations (also demonstrated in the species studied) and with external morphological differences, it appears that the trisomics and tetrasomics could serve to explain the aneuploid increase in the Genus from n=7 to 9 and to 11.
    Interspecific crosses among all the species produced only one type of hybrid, I. pectinata female×I. amara male. Results from the interspecific crosses as well as sterility of abnormal buds indicated that there is a strong genetic barrier between species and gametes with different chromosome numbers.
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  • C. B. S. R. Sarma
    1968 Volume 33 Issue 1 Pages 94-96
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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  • Seymour H. Sohmer
    1968 Volume 33 Issue 1 Pages 97-99
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Microsporogenesis was investigated in selected cultivars of Manihot esculenta being cultivated at the Instituto Interamericano de Ciencias Agricolas in Turrialba, Costa Rica. The course of microsporogenesis was found to be “normal” in these cultivars and various stages of the process were recorded.
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  • T. Narasimha Das, A. Sudharsan Raj, B. V. Ramana Rao
    1968 Volume 33 Issue 1 Pages 100-111
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Cytological observations in Vicia faba using asafoetida revealed that asafoetida could cause aberrations and be used as a mutagen. About 0.1% to 0.2%/ of natural mutations do occur in Vicia faba. Since water treatment caused some aberrations it may be presumed that certain chemicals which are present in seed coat of Vicia faba must be soluble in water and in turn acting as automutagenic substances. Coumarins cause mutations. Since asafoetida is having umbelliferone which is 7-hydroxy coumarin it must be acting as a mutagen. So asafoetida can be used as a cheaply available mutagen. But how far this mutagen can be used in boosting up Agricultural production needs further investigation.
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  • Yoshio Nakao, Yuh H. Nakanishi, Bungo Wada
    1968 Volume 33 Issue 1 Pages 125-136
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. The behavior of centrioles in spermatocyte meiosis of silkworms and of grasshoppers was reinvestigated by in vivo observations and by the use of improved fixatives.
    2. In both insects, the centrioles behave exclusively outside the spindle membrane. The centrioles participate in the sperm-tail filament formation at the spermatocyte stage in silkworms and at the spermatid stage in grasshoppers. However, no centrioles participate in spindle formation.
    3. Taking these facts into consideration, it is concluded that the centriole is intrinsically a primordial organelle for flagellum formation of the sperms and remains in an inactive state in other than male gametic cells in animals.
    4. Based on the atractoplasm theory, suggestions are made concerning the mechanism of mitosis for some divergent achromatic figures and on the generalization of mitosis mechanisms in plants and animals.
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  • Gurdev S. Khush, Charles M. Rick
    1968 Volume 33 Issue 1 Pages 137-148
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Telotrisomics-sporophytes possessing a telocentric chromosome in addition to the normal complement-were obtained and studied for six different chromosome arms of the tomato. They originated in the progeny of the following kinds of chromosomal deviants: terminal deficiency, tertiary monosomic, and compensating trisomic. Cytological studies at meiotic pachytene established that the centromere of three telocentrics was flanked by a heterochromatic chromomere opposite the intact arm and three appeared to have terminal centromeres. Of the latter group the centromere of two appeared to be of normal size, while one was about half normal size, its chromosome being the only one of the six telocentrics to be mitotically unstable. The longer the telocentric arm, the greater the tendency to form trivalents; when trivalents are not formed, the telocentric is invariably univalent, the preferential pairing between the two normal homologues leading exclusively to 12:12+telocentric anaphasic separations. Consistent with this cytological behavior, only one in several hundred trisomic progeny was of primary type, the rest telosomic.-The effects of the extra telocentric chromosome on gross phenotype of the plant are much greater for the long arms, and telocentrics for long arms closely resemble the corresponding primary trisomics. As a result of gametophytic elimination, the telocentric is never substituted for the corresponding normal chromosome, but can be transmitted as an extra element for all studied telocentrics on the female side and for the short arms also on the male side. The rate of female transmission generally exceeds that of the corresponding primary trisomic.-Inheritance studies of three telotriosmics permitted assignment of marker genes to their proper chromosome arms. Since efficiency of the trisomic ratio method is enhanced if the telotrisomic is phenotypically distinguishable from the diploid, trisomics for the long arms are better suited for genetic mapping purposes than those for short arms. In this fashion r and wf were proven to lie on 3S, rv and sf on 3L, var on 7S, and cpt on 8L, with correspondingly closer approximations of centromere positions. The incompletely dominant gene La was assigned to 7L by virtue of dosage effects in heterozygous triplo-7L. Considering their higher rates of transmission and less depressing effects on vigor and fertility, extra telocentrics render telotrisomics more useful for determining arm locations than either secondary or tertiary trisomics.
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  • M. S. Chennaveeraiah, D. G. Krishnappa
    1968 Volume 33 Issue 1 Pages 149-154
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The cause of sterility in Solanum wendlandii Hook. (2n=24) which is reproductively known to be a fertile plant in U.S.A. is revealed here by the desynaptic behaviour of chromosomes. The cytological observations reveal that only a few PMC's show normal behaviour of chromosomes. In most of the other cells, only a few bivalents are formed associated with varying number of univalents which range from 4 to 20 in a cell. Occasionally complete desynapsis has also been observed with 24 univalents. In addition, their behaviour at anaphase I and II is highly irregular. The unequal disjunction is a frequent phenomenon with a distribution of 2+22, 4+20, 6+18, 9+15, 10+14 etc., at the poles. The tetrad formation is also irregular. More than 60% of the pollen grains look empty. Thus there is a high degree of pollen sterility due to desynaptic behaviour of chromosomes, which may be due to partly genetical and partly environmental conditions.
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  • Part III. Fine structural aspects of early phragmoplast development in the absence of an organized mitotic spindle
    A. G. Underbrink, L. V. Olah
    1968 Volume 33 Issue 1 Pages 155-164
    Published: March 25, 1968
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The fine structure of the early developmental stages of anomalous phragmoplasts which occur during spindleless mitoses induced by digitonin in Allium cells was studied. Although spindle formation is suppressed, these anomalous phragmoplasts are functional in that a cell plate is produced. These phragmoplasts appear to develop initially from a proliferation of membranous profiles which are associated with the chromosomes. Later stages in the development of the phragmoplasts are recognized as localized, discrete aggregates of membranous elements situated among the chromosomes. During telophase, the restituting nucleus partially surrounds the aggregations of phragmoplast elements. As a result, one part of the developing cell plate and subsequent cell wall always remains lying in an indented part of the post-mitotic nucleus. It is suggested that the membranous profiles which proliferate among the chromosomes could be derived from fragments of the ruptured nuclear envelope.
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