CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
44 巻, 1 号
選択された号の論文の31件中1~31を表示しています
  • III. Meiotic abnormalities
    Narsinha Dayal
    1979 年 44 巻 1 号 p. 1-5
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Meiotic abnormalities were studied in three inbred lines of radish (Raphanus sativus L. var. radicola Pers.), namely LS-337/24, LS-337/25 and LS-43/51, their F1 hybrids and the original population. Plants of the inbred lines showed greater meiotic abnormalities at metaphase I and anaphase I in comparison to those of hybrids and the original population. Univalents and anaphase bridges with or without fragments were more frequently present in the inbred lines whereas they were almost absent in the hybrids and the original population. Besides other meiotic abnormalities such as stickiness, desynapsis, non- and unequal segregation of chromosomes at anaphase I, laggards, premeiotic errors etc. were also noted in the inbred lines. It has been demonstrated that meiotic abnormalities in radish is genotypically controlled. The mechanism of the formation of anaphase bridges has also been discussed.
  • Germination of pollen grains on stigma
    Narsinha Dayal
    1979 年 44 巻 1 号 p. 7-12
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Pollen germination on the stigmatic surface and further development of pollen tubes in the style have been studied in two inbred lines of radish (Raphanus sativus L. var. radicola Pers.), namely LS-337/24 and LS-337/25, their F1 and backcross hybrids and the original population in order to understand the mechanism of reduced fertility of the inbred lines. The inbred lines differed significantly among themselves and from the original population in pollen germination on stigma under identical condition of pollination; pollen germination in the inbred lines is much lower in the inbred lines. Pollen grains of LS-337/25 germinated quite well on the stigma of LS-337/24 and the F1 hybrid LS-337/24×LS-337/25, but the pollen grains of LS-337/24 showed poor germination on the stigma of LS-337/25 and the F1 hybrid, indicating its genotypic peculiarity. Differences among lines, hybrids and the original population were also noted in style length, stigma morphology and the number of pollen tubes in the style. Possible mechanism of semi-sterility of the inbred lines has also been discussed.
  • S. S. N. Sinha
    1979 年 44 巻 1 号 p. 13-19
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Leaves of a mutant plant (whitish yellow in colour) were studied with electron microscope. The ultrastructure of the plastids of the chlorophyll mutants showed deformed or degenerated grana with disintegration of stroma lamellae. This may be attributed to the changes in the nature of the gene, controlling the development of the chloroplast. Such an abnormality may be caused by genetic blocking of the production of some enzyme controlling the development of the lamellar system. Complete degeneration of the lamellar system follows. Vesicles present in the chloroplast may be the out come of lamellar disintegration. In lentil the very rare occurrence of xantha or albina mutants may be due to more than one gene responsible for controlling the development of the ultrastructures of plastids.
  • Antonio J. Tambasco, Marcos A. Giannoni, Lilia M. de Azevedo Moreira
    1979 年 44 巻 1 号 p. 21-27
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Chromosomes of M. quadrifasciata anthidioides pupae, obtained by squash preparations from ovaries, were analysed through proteolitic digestion with trypsine and subsequent staining with Giemsa. The G-bands were described according to the nomenclature proposed by the Paris Conference (1971) for human metaphasic chromosomes.
  • B. N. Verma
    1979 年 44 巻 1 号 p. 29-38
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Four species of Pithophora viz. P. kewensis, P. zelleri, P. polymorpha and P. roettleri were collected from different localities of Ranchi and Muzaffarpur and their cytology has been worked out.
    The nuclei at growing end cells have been found to be smaller, deeply stained and crowded than rest part of the cells. In all species at hand, except P. kewensis, abnormal nuclei of various shapes and sizes have been observed in addition to normal ones which are spherical. The number of abnormal nuclei are fairly high in older cells and they are very faintly stained, presumably due to poor chromatin material.
    The diameter of interphase nuclei has been found to be inversely proportionate to the number of nuclei present in the cells. Form having low number of nuclei possesses bigger nuclei than those having comparatively higher number of nuclei. Such a correlation between the dimension and number of nuclei has not been reported so far in other genera of Cladophorales.
    Nuclear division in P. kewensis has been observed exclusively mitotic while in rest of the three genera, it is accomplished partly by mitosis and partly by amitosis. Amitotic division takes place by furrowing and not by nuclear plate formation. It has been assumed that amitotic division in Pithophora is an adaptation to its week metabolic process. Further, it has been held that amitosis in this genus, may be compensatory to the absence of sexual reproduction and/or polyploidy and that it might have played a significant role in speciation of the genus.
    Unlike other genera viz. Cladophora Kutz., Rhizoclonium Kutz. and Chaetomor-pha, mitotic nuclear, division in all the four species under study, is confined to a particular region of any cell and different stages i. e. from prophase to telophase in succession have been observed in a single cell.
    Chromosomes at metaphase in each of four species at hand organize on an equatorial plate exceeding the diameter of interphase nuclei. Sticky nature of the metaphase chromosomes has been experienced consistently during the course of investigation and hence it seems to be a characteristic feature of the genus.
    The chromosomes at metaphase have been counted as 24 in P. kewensis and P. zelleri and as 36 in P. polymorpha and P. roettleri. Chromosome number in three species viz. P. zelleri, P. polymorpha and P. roettleri has been reported for the first time whereas in P. kewensis, it is confirmation of earlier finding of Patel (1971). Since meiosis has not been ascertained so far in Pithophora, haploid or diploid nature of worked out chromosome numbers has not been expressed. Basic chromosome number as 6 has been suggested for Pithophora.
  • Catalina Romero Lopes, Edmondo José de Lucca, Ana Maria de Andr ...
    1979 年 44 巻 1 号 p. 39-47
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    The present paper describes the karyotype and plasma esterase isozymes in 10 species and one hybrid of Columbiformes.
    The genus Columba showed the greatest enzymatic polymorphism but was uniform as to the diploid chromosome number. Esterase data showed a high affinity among Leptotila, Geotrygon and Columba. Among Claravis, Columbina and Scardafella no variability in the electrophoretic patterns was found but a high chromosomal diversification was observed.
    These data enabled us to propose some modifications in the previously proposed phylogenetic relationships.
  • J. N. Rai, A. Saxena, H. J. Chowdhury
    1979 年 44 巻 1 号 p. 49-57
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    The development of ascocarp and the nuclear behaviour during the development of ascus and ascospores was studied in Achaetomiella virescens. The ascocarp development in A. virescens begins with the formation of deeply staining ascogonial coils as lateral branches of the vegetative hyphae. As these coils develop into multicellular, multinucleate ascogonia, they are surrounded by a pseudoparenchymatous envelope. This ascocarp initial in later stages of development gets differentiated into a central sporogenous core and wall layers. The central sporogenous core breaks and becomes a loose mass of multinucleate cells. Some of these multinucleate cells become meristematic and give rise to ascogenous cells at the base of developing ascocarp. Asci are formed from these ascogenous cells by croziers. Four divisions result in binucleate ascospores and each mature ascospore has a single nucleus. The haploid number of chromosome is 6 (n=6).
  • V. Cytogenetic studies on P. somniferum×P. setigerum hybrids and amphiploids
    C. P. Malik, T. N. Mary, I. S. Grover
    1979 年 44 巻 1 号 p. 59-69
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Hybrids between Papavr somniferum and P. setigerum had mean pairing as 10.7II+11.6I at metaphase I. Rarely one trivalent was also observed. Late stages of meiosis indicated abnormalities e.g. laggardism, precociously dividing chromosomes etc. In the F2, plants with 2n=23-34 chromosomes were obtained.
    i. The presence 12II in the triploid hybrids indicated homologies between somniferum and setigerum genomes. In addition autosyndesis between some of the chromosomes of second setigerum genomes also occurred.
    ii. The amphiploids, raised following colchicine treatment, had mean pairing of .65IV+.65III+26.9II+7.65I at metaphase I. There was low frequency of multivalents. The bivalent pairing is attributed to strong differential affinity be-tween chromosomes of the same origin in the amphiploid. The occurrence of a genetic system promoting bivalent formation in the setigerum species is envisaged.
    iii. The possible role of other species e.g. P. glaucum, P. orientale and P. aculeatum in the origin of P. somniferum and P. setigerum is discussed.
    iv. In addition F2, backcrosses have also been cytogenetically analysed and their data are used in interpreting the genome relationships of somniferum and setigerum species.
  • Donna Cachita-Cosma, Constantin Craciun
    1979 年 44 巻 1 号 p. 71-75
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    The epidermal cells of peony petals immersed for a couple of hours in chlorhydric procaine (of 1000 ppm concentration) undergo a physico-chemical alteration of the colloids in the vacuolar sap. As a consequence, some corpuscle formations, of lipo-proteic nature, appear in the vacuolar sap; in optic micro-scopy they have a hyaline aspect, are strongly refringent and may add the vacuolar dye. Observations carried on in electron microscopy allowed us to make sections through these corpuscles (48 hours after the tissues were introduced in procaine solution) and an electronically dense aspect was remarked. By their sectioning, the corpuscles suffered a surface undulating process. As the procaine accumulates in the cell, an evolution of the corpuscle forming process is obvious, in the course of time. The process becomes stable 48 hours after the treatment is applied; the corpuscles are large and manifest the tendency to anchor in the tonoplast, forming deposits.
  • S. C. Verma, D. Ohri
    1979 年 44 巻 1 号 p. 77-90
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Chromosome studies based on Feulgen-stained squashes of pretreated and untreated root-tips of eleven cultivars and three local weedy populations of Lathyrus sativus L. (f. Leguminosae) have shown consistent variation in the karyotype between the strains. There is also observed considerable variation between the strains as regards total chromosome length and volume at metaphase in root meristems, and this variation is by and large developmental, and this has been confirmed by detailed analysis on four varieties. Further substantiation on the nature of such variation is derived from microdensitometric estimations of nuclear DNA of a sample of four cultivars, showing wide differences in TCV. There is general constancy of nuclear DNA, suggesting that the observed variation in chromosome volume does not involve the genetic material. It could be due to variation in the protein component.
    The prophase chromosomes show precocious condensation of centromeric regions producing a characteristic proximal-distal gradient, suggestive of hetero-chromatin. Contrary to the earlier reports, the present observations reveal in general 2 SAT-pairs in the complement, one with small satellite and the other with a large chromosome segment distal to the secondary constriction. A very notable feature of cells at prophase is the occurrence of upto 4 fragments, resulting from the disarticulation of the satellites of 2 SAT-pairs, implying weak secondary constrictions.
  • S. C. Verma, D. Ohri
    1979 年 44 巻 1 号 p. 91-102
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    The locally cultivated material of Rhoeo spathacea (=R. discolor) is totally pollen sterile, irrespective of the time of the year. Meiotic analyses of random samples have shown complete breakdown of the well known Rhoeo system. A fully opened-out ring of 12-chromosomes is not observed, and a chain of twelve occurred only rarely. The chiasmata are not confined only to the pairing segments, but also occur in the interstitial and differential segments which, very often leads to a break-up of the interchange complex into two to five groups. The orientation at metaphase I is basically non-disjunctional, and often unequal distribution occurs at anaphase I. Pollen mitoses revealed sub-haploid, hyper-haploid, diploid and tetraploid pollen. It is suggested that during its long history of cultivation through vegetative means, several mutations may have accumulated upsetting the genetic control on chromosome pairing limited only to the pairing segments. We suggest that most of the pollen sterility is segregational and recombinational in origin; and there is also the probability of the occurrence of mutations causing pollen sterility or the occurrence of some developmental block originating outside the pollen perhaps mediated by environmental factors, as yet unidentified.
  • F. S. Bokhari
    1979 年 44 巻 1 号 p. 103-109
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Chromosome numbers were counted in the control material. New count was made i.e., 2n=42 in C. eragrostis.
    Study of the germination percentages and survival percentages of three mem-bers of Cyperaceae and one species of Luzula, show that there is only a slight difference between numbers germinating and numbers surviving. The opposite is true for plants with a localised centromere.
    Study of the survival percentages in the M1, M2 and M3 generations of the above four plants with diffuse centromeres, shows a general reduction in survival in M2 and only a very slight improvement, if not further reduction, in M3. By contrast, in plants with localised centromeres, there is nearly 100% survival in M2 at doses where seeds from the M1 plants are viable.
    Overall, the prossession of a diffuse centromere confers no advantage, following seed irradiation.
  • S. S. Raghuvanshi, D. N. Singh
    1979 年 44 巻 1 号 p. 111-121
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Comparative radiosensitivity of five varieties of Impatiens balsamina has been studied. Different parameters like germination/survival, growth, meiotic anomalies, pollen fertility and seed setting were taken into consideration. Response of varieties to germination survival and growth parameters was fairly uniform, but not so with regard to other parameters. A new approach for comparing radiosensi-tivity has been discussed. Stimulatory effect of radiation on chiasma frequency and seed setting in one of the variety has been reported. Insignificant difference in INV and ICV of five varieties have been reported. ICV appears not to reflect on the radiosensitivity. Genotypic constitution is responsible for the varietal difference in radiosensitivity. Study of trisomic in M2 has been presented.
  • Umrao Singh, H. K. Jain
    1979 年 44 巻 1 号 p. 123-133
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    A number of chemicals including actinomycin D, mitomycin C, cycloheximide, 5-fluorodeoxyuridine (FUDR) and potassium pyrophosphate (K4P2O7; 3H2O) have been tested for their effects on chiasma formation in the pollen mother cells of Delphinium ajacis. These chemicals are known to inhibit the syntheses of macromolecules like DNA, RNA or proteins. In general, it has been found that all the chemicals bring about a significant reduction in chiasma frequency. An exception, however, is provided by mitomycin C which increases chiasma frequency at lower concentrations and decreases it at higher concentrations. Another important finding is that none of the chemical treatments resulted in a failure of chromosome pairing. FUDR has been found to induce chromosomal aberrations in addition to its effect on chiasma frequency. The significance of these findings in relation to the mechanism of crossing over has been discussed.
  • Egbert W. Henry
    1979 年 44 巻 1 号 p. 135-152
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    The ultrastructural localization of peroxidases, during ethylene-induced abscission, in flower pedicels of Nicotiana tabacum L. cv. ‘Little Turkish’, has been investigated. Peroxidase activity has been localized in the plasmodesmata of abscission zone tissue that had been fixed in glutaraldehyde and subsequently incubated in diaminobenzidine (DAB) medium with post-fixation in osmium tetroxide. Preincubation of tissue in potassium cyanide, prior to incubation in DAB medium containing the inhibitor, demonstrates a significant reduction in DAB staining. Incubation of tissue in aminotriazole (an inhibitor of catalase activity), prior to incubation in DAB medium containing the inhibitor, does not inhibit the peroxidase activity in plasmodesmata incubated in DAB medium; however, aminothiazole does inhibit catalase present in the microbodies of DAB incubated tissue. It is suggested that proliferating plasmodesmata, in response to ethylene treatment, exhibit enhanced peroxidase activity and allow for the increased mobilization of peroxidase to the middle lamellar areas of the cell walls of abscising cells.
  • Jean Dexheimer
    1979 年 44 巻 1 号 p. 153-160
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    The object of this paper is to describe more precisely the ultrastructural localization of glucose-6-phosphatase activity in the cells of digestive glands of Drosera capensis during the mucigenic phase. The detection reaction is specific and very sensitive to fixing by glutaraldehyde.
    At no time was any activity detected in the endoplasmic reticulum or the dictyosomes. As in all plant specimens studied previously, the plasmalemma was very active. However, the majority of the glucose-6-phosphatase activity was concentrated in the cell wall, in the zones where mucilage accumulate (parietal “protuberances”, peripheral and median zones of the cell wall). It has not been possible to determine the significance of this localization.
  • J. Venkateswarlu, K. G. Raja Rao
    1979 年 44 巻 1 号 p. 161-166
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Pachytene chromosome morphology of P. pubescens L., (n=12) was studied. The twelve chromosomes were identified individually high lighting their diagnostic features and an idiogram, constructed on the basis of total chromosome length, lengths of chromatic and achromatic segments and arm ratios, was provided. Chromosome 8 has the nucleolus organiser in the totally chromatic short arm.
  • A. K. Singh
    1979 年 44 巻 1 号 p. 167-174
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    An autotetraploid was raised as a result of colchicine treatment in double whorlled, pink coloured variety of Portulaca grandiflora. In C2, segregants in different proportions with regard to number of floral whorls (1-∞), were observed. Selfed seeds from C2of individual type, showed further segregation in C3. Studies indicated that this trait is controlled by multiple gene system. Although, pollen sterility was not significantly affected by different number of whorls, however, seed setting showed direct correlation with number of whorls. Gynoecium and staminal transformation into petaloid structures was noted. The possible cumulative, pleotropic effects of present multiple gene system has been discussed.
  • Frank P. Cheng, Richard E. Crang
    1979 年 44 巻 1 号 p. 175-179
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Mouse L-cells in log phase were treated with cytochalasin B for time periods ranging from 20 sec to 1 h and subsequently examined by means of scanning electron microscopy. Zeiotic blebs appeared within the shortest time period in all cells but was accompanied by a general loss of microvilli in spindle and stellate shaped cells. It is suggested that initial responses in zeiotic bleb formation may be dictated by the amount of pre-existing membrane per unit area of the cell surface, i. e., the extensiveness of microvilli.
  • C. N. Sun, S. B. Cheng Chew, H. J. White
    1979 年 44 巻 1 号 p. 181-190
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    The fine structure of the smooth muscles in a land Turbellarian, Bipalium Kewense, has been studied. These muscles are composed of three types myofilaments. Besides the thick and the thin filaments, there is a third type of intermediate filament which forms networks to connect between the dense bodies. The nucleus, mitochondria, sarcoplasmic reticulum are mainly at the periphery of the muscle.
    Two types of glycogen granules with different sizes have been encountered; both scattered among myofilaments as well as close to mitochondria. One type exhibits a round granular appearance while the other is usually of a rosette form. Dense bodies closely associated with the sarcoplasmic reticulum, which are vesicular or tubular in appearance, are also encountered. The possible evolutionary aspects of skeletal muscle are considered.
  • I. Mitotic analysis in fourteen species
    S. S. N. Sinha, H. Roy
    1979 年 44 巻 1 号 p. 191-199
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
  • Meiotic analysis of sixteen species
    S. S. N. Sinha, H. Roy
    1979 年 44 巻 1 号 p. 201-209
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
  • Sukhraj S. Dhillon
    1979 年 44 巻 1 号 p. 211-214
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Cytological studies have been made in two West-Himalayan species of Scrophularia for the first time. A new base number x=12 is suggested for the genus and hence S. himalensis (n=24) and S. polyantha (n=12) are tetraploid and diploid species. The presence of B-chromosomes has been observed in both species and their significance in the origin of new base number is described.
  • II. Immature forms
    C. N. Sun, H. J. White
    1979 年 44 巻 1 号 p. 215-220
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    A variety of abnormalities of immature spermatozoa can be observed. Examples include cells with four condensed nuclei at various stages of maturation, a honeycomb type of nuclear envelope, abnormal pieces of acrsomes, membranous structures of various origins, and finally, occasional annulate lamellae.
  • Susan Abraham, Mathew P. Koshy
    1979 年 44 巻 1 号 p. 221-225
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    In a cytogenetic study on dividing root tip cells of onion, extract of green chillies was evaluated for cytotoxic and mutagenic effects in comparison with an untreated control group.
    The occurrence of achromatic lesions or ‘gaps’, chromosome breakage, chromosome clumping etc. were noticed in the treated cells. The frequency of abnormal metaphases was determined in the different treatments.
    The present study has shown that extract of green chillies (Capsicum annum) produces irrepairable damage in root tip cells of onion. It is advisable to limit the use of chillies in food as far as possible.
  • K. J. Madhusoodanan, O. P. Arora
    1979 年 44 巻 1 号 p. 227-232
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Matricaria chamomilla L. is a diploid species (2n=18) the flowers of which are important source of an oil commonly known as ‘Blue oil’. Improvement through artificial chromosome doubling gave favourable response resulting in larger and longer lasting capitula. Tetraploid showed typical autoploid meiotic behaviour and normal fertility.
  • P. N. Mehra, S. K. Sachdeva
    1979 年 44 巻 1 号 p. 233-240
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Twenty one taxa belonging to 18 species of monocots are studied. Four species i.e. Alocasia acuminata (2n=28), Cautleya lutea (n=12, 13), Carex insignis (n=24) and C. longipes (n=21) are investigated for the first time. New chromosome numbers are reported for another three species, namely, Globba hookeri (n=12), Carex filicina (n=21) and Fimbristylis complanata (n=10). Heteromorphic chromosome pairs are noticed in Paris polyphylla (2n=20).
  • S. S. Raghuvanshi, D. N. Singh
    1979 年 44 巻 1 号 p. 241-247
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Polyploidy has been induced in four varieties of Impatiens balsamina L. The most effective treatment for induction of polyploidy was found to be 0.2% aquous colchicine for 12 hours. The induced tetraploids were characterised by increase in height, size of flowers and late and longer blooming period. Despite good pollen fertility, polyploids have poor seed setting. Reasons for low frequency of multivalents in all the varieties have been discussed. Significant increase in chiasma frequency (C2) of 4n of three varieties have been reported. For most of the parameters distinct differences at varietal level in tetraploid were noted which appears to have genotypic base.
  • Bungo Wada
    1979 年 44 巻 1 号 p. 249-258
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Both unrestricted cell proliferation and somatic cell mutation of cancer cells of all kinds are, at least in their starting points, intrinsically subjects of cytology and genetics but not of medicine. The explanation of these subjects is practically impossible without an elucidation of the mechanism of mitosis and of the genetic information of genes which control cell proliferation, cell differentiation, and metabolism of tissue cells of organs bearing cancers.
    Based on in vivo observations and genetic information on mitosis in eukaryotes, it has been become clear that a spherical metabolic nucleus (a resting nucleus) continuously changes into a spindle-shape mitotic nucleus (a metaphases pindle) in prometaphase. This change of the nucleus is predicted and performed by the spindle formation inducer gene (SFI gene). In the cell division of eukaryotes, karyokinesis always goes ahead of cytokinesis and, cell proliferation and cell differentiation take place antagonistically. Accordingly, prior to entering into cell differentiation, each cell stops its mitosis under the genetic information of the spindle formation repressor gene (SFR gene).
    If an epidermic primordial cell of an organ would happen to suffer a deficiency of the SFR gene from any internal or external cause, the cell would aquire a characteristic of unrestricted cell proliferation without cell differentiation and this character would be passed on to the offspring by mitosis. The deficiency of the SFR gene is inferred to be introduced by a recombination error of the gene DNA in chromosomes in the S-phase of dividing tissue cell nuclei. The DNA fractions would appear in and be diffused from the damaged cell nuclei treated with any carcinogens.
    The common idea that cancers are composed of embryonal cells is nothing but an old doctrine established upon fixation cytology. Any differentiated tissue cells which can renew themselves by metabolism, always maintain the genes for mitosis and those for cell differentiation in active states. Thus, variously different characters of cancers shown in different organs are nothing but a modified manifestation of phenotypes of genes which characterize each organ. The diversified characteristics of cancers imply, therefore, no evidence of a plurality of causes in carcinogenesis. The author maintains his opinion that the ultimate cause of carcinogenesis is unitary, namely the deficiency of the SFR gene induced in organs treated with carcinogens.
    Abnormalities of chromosomes, mitosis, physiology, biochemistry, enzymology, immunological reactions, etc. which appear in young or old cancer cell clumps are modified phenotypes manifested secondarily or thirdly by the genetic information of genes in differentiated tissue cells of organs bearing cancers in a teleonomy responding to their changing circumstances due to cell proliferation and growth.
    Extensive research papers on cancers are concentrated mostly on secondary or tertiary changes in cancer cell clumps. These studies may contribute greatly to cancer therapeutics but very little to the elucidation of the intrinsic nature of cancer cells. The descriptions of mitosis in text-books are too old and are in disregard of any principles of modern genetics and of the data on mitosis in living eukaryotic cells.
  • M. S. Jolly, S. K. Sen, G. K. Prasad, A. K. Sengupta
    1979 年 44 巻 1 号 p. 259-263
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
  • Tosihide H. Yosida
    1979 年 44 巻 1 号 p. 265-274
    発行日: 1979/03/25
    公開日: 2009/03/19
    ジャーナル フリー
    Some genetic aspects are presented on C-band polymorphism in 62 Japanese black rats (R. rattus tanezumi) of a breeding colony origin. Among 20 autosome pairs, nos. 1, 3, 7, 8, 10, 11 and 13 are polymorphic regarding the presence or absence of C-bands. Pairs no. 2, 4, 5 and 6 are devoid of C-bands, while pairs no. 9 and 12, and other small metacentric pairs (nos. 14 to 20) carry C-bands. In pair no. 1 showing acrocentric and subtelocentric polymorphism, merely the acrocentric member shows C-band. Such correlation between the banding pattern and the chromosome type is not found in pairs no. 9 and 13, though there occurs acrocentric and subtelocentric polymorphism in them. Results of genetic analysis of C-band polymorphism carried out in 24 offspring from 5 litters coming from different parents indicate that the C-band characteristics of the black rats show a regular segregation in offspring with the Mendelian ratio.
feedback
Top