CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
7 巻 , 4 号
選択された号の論文の10件中1~10を表示しています
  • M. Nawaschin, Helene Gerassimowa
    1936 年 7 巻 4 号 p. 437-465
    発行日: 1936/12/30
    公開日: 2009/03/19
    ジャーナル フリー
    1. Alle die uns zur Verfügung stehenden Daten beweisen, daß beim Altern des im Samen eingeschloßenen ruhenden Embryos Mutationsveränderungen der Chromosomen vor sich gehen, die einen massenweisen Charakter annehmen können. Die Hypothese, nach welcher die Erhöhung des % der Mutanten unter den aus alten Samen erzogenen nichts anderes ist als eine rein arythmetische Folge des vorwiegenden Absterbens der nicht mutanten Embryonen, muß fallen gelassen werden, denn sie widerspicht den Tatsachen.
    2. Die Ursache dieser Mutationsveränderungen kann nicht in der Akkumulation der natürlichen Radiation während einiger Ruhejahre des Embryos liegen. Man kann berechnen, daß die wirkliche natürliche Irradiation höchstens 1/750 der tatsächlich beobachteten Mutationen hervorbringen könnte. Diese Schlußfolgerung zeigt gute Übereinstimmung mit den Daten, die von anderen Autoren für die Genmutationen bei der Drosophila erhalten wurden.
    3. Der eigenartige physiologische Zustand des ruhenden Embryos, die Tatsache des Mutationseffektes der erhöhten Temperatur und Feuchtigkeit, die Existenz von “Mutationsgenen” usw. machen den Zusammenhang der Mutation mit physiologischen Veränderungen in der Zelle sehr wahrscheinlich. Über die Natur dieser Prozesse läßt sich allerdings bis jetzt nichts bestimmteres aussagen.
    4. Mutationsveränderungen entstehen wahrscheinlich noch in ruhenden Zellen; dies geht hervor aus ihrer sehr großen Mannigfaltigkeit, die sich schon bei den ersten Zellteilungen des keimenden Embryos geltend macht, und aus der raschen Reduktion dieser Mannigfaltigkeit auf 1-2 Sorten von Veränderungen, die bei der weiteren Entwicklung erhalten bleiben. Entstünden während der Entwicklung des Individums fortgesetzt neue Mutationen, so hätten wir ein anderes Bild. Die Daten einiger Autoren, die auf die Existenz einer “Hachwirkung” des Mutationsfaktors hinweisen, fanden keine Bestätigung in der vorliegenden Untersuchung: der einfache sektoriale Aufbau der mutanten Pflanzen ist der beste Beweis dafür, daß die Mutationsveränderungen im Augenblick des Beginns der individuellen Entwicklung schon vorhanden sind und im Verlauf dieser Entwicklung nicht mehr entstehen.
    5. Die Verteilng der mutanten Zellen im Körper des Embryos ist zunächst eine zufällige. Es kommt aber bald zur Eliminierung der Mehrzahl der mutanten Strukturen (infolge ihrer Lebensunfähigkeit), und es entwickelt sich eine Chimärenpflanze, die am häufigsten aus einigen wenigen Sorten von Gewebe zusammengesetzt ist. Dank der frühen Differenzierung der Meristeme und dem unabhängigen Mutationsgange ihrer Zellen besteht kein Zusammenhang der oberirdischen und unterirdischen Teile hinsichtlich der Mutationsvariabilität. Die mutierten Gewebe können einen beliebigen Teil der Pflanzen bilden (die Reproduktionsorgane mit eingeschlossen).
    6. Der Prozentsatz der Mutanten unter den aus alten Samen erzogenen Pflanzen ist im allgemeinen desto höher, je länger die Zeitperiode war, die die Samen im Ruhezustande verbrachten; er zeigt indessen starke Schwankungen, indem er in einzelnen Fällen 50% und mehr erreicht und andererseits bis auf einige wenige Prozente absinkt. Diese Schwankungen hängen anscheinend von einer Reihe akzessorischer Ursachen ab, von denen die wichtigste in der hohen Sterblichkeit der Mutanten in frühen Entwicklungsstadien liegt. Diese Ursache führt manchmal zu einer sehr merkwürdigen Situation, denn es können nämlich aus außerordentlich stark mutierten Embryonen nur sehr wenige Mutanten erhalten infolge des Untergangs der Keimlinge in ersten Keimungsstadium und des Überlebens von nur einzelnen zufälligen Exemplaren
  • N. N. Sokolow, G. G. Tiniakow, J. E. Trofimov
    1936 年 7 巻 4 号 p. 466-489
    発行日: 1936/12/30
    公開日: 2009/03/19
    ジャーナル フリー
    1. The present work has had for subject a morphological study of the following specimens of Gallinaceae: common fowl (Gallus domesticus), Caucasian pheasant (Phasianus colchicus), silver peasant (Nycthemerus argentatus), peacock (Pavo cristatus), guineafowl (Numidae meleagris), turkey (Melagris gallopavo), woodcock (Tetrao tetrix).
    The individuality of the largest elements of chromosome complements has been established for all these specimens; the corresponding caryograms are given in Figs. 2, 4, 6, 8, 10, 12, 14. The general aspect of the chromosome complement in each specimen can be respectively seen in Figs. 1, 3, 5, 7, 9, 11, 13, 15, 17, 19. Determination of the chromosome numbers has not been aimed at in the present research.
    2. The comparison of the individual chromosomes studied between themselves has revealed a similarity of a number of chromosomes. On the strength of morphological data and the length of chromosomes, a table has been drawn (Fig. 15). As a result, fourteen chromosome types have been ascertained in Gallinaceae (Fig. 16).
    3. The material obtained enables us to distinguish two groups of caryotypes; the first group, embracing common fowl, peacock guinea-fowl, is characterized by the presence of numerous chromosomes with two arms; the second group containing Caucasian pheasant, silver pheasant, turkey, stone partridge (according to data obtained by Peshkovskaia) is characterized by the prevalence of rod-shaped chromosomes with a terminal spindle fiber attachment.
    4. The strong similarity between the caryotypes of a number of large individual chromosomes of the specimens studied leads the authors to the conclusion that in the evolution of Gallinaceae the divergence of separate forms was in the main not followed by any morphological changes in chromosomes, being apparently due to mutations of genes.
  • A. A. Moffett
    1936 年 7 巻 4 号 p. 490-498
    発行日: 1936/12/30
    公開日: 2009/03/19
    ジャーナル フリー
    1. Twenty-one species and varieties of Lachenalia examined showed four different basic numbers x=7, 8, 11 and 13. A polyploid series 3n, 4n and 6n occurs with the basic number 7.
    2. The somatic chromosomes are of unusual shapes, frequently tapering towards the ends. Certain chromosome resemblances are traced between species with different basic numbers. Chromosome morphology indicates that the higher basic numbers have not arisen by fragmentation of chromosomes.
    3. The higher basic numbers are therefore perhaps derived from the lower, as secondarily balanced numbers. Probably this is the most frequent mode of origin of new basic numbers in a genus. Secondarily balanced basic numbers may arise by the formation of a polyploid series in the original number, followed by interspecific hybridisation between different polyploids.
  • William Bryden
    1936 年 7 巻 4 号 p. 499-503
    発行日: 1936/12/30
    公開日: 2009/03/19
    ジャーナル フリー
    1. Normally descended testes of white rats have been placed in the abdomen for varying lengths of time and sections were made to examine the stages of meiosis.
    2. Obvious differences in late prophase and metaphase stages were observed in the 28 day and 12 day forms.
    3. The types of bivalent found have been illustrated and discussed.
    4. The chiasma frequencies of the experimental forms compared with those for the normally descended forms have been compared and no significant differences result.
    5. The degrees of terminalisation do not point to there being any real differences from such a movement of chiasmata.
    6. Presence of spermatozoa is markedly different in the normal and experimental forms.
    7. Those animals in which the testes remained in the abdomen for 28 days, showed a somewhat disorganised state of the bivalents at metaphase.
    8. It can be concluded that the raised temperature within the abdomen is sufficient to sause such a disorganisation.
  • Elliot Weier
    1936 年 7 巻 4 号 p. 504-509
    発行日: 1936/12/30
    公開日: 2009/03/19
    ジャーナル フリー
  • H. Pfeiffer
    1936 年 7 巻 4 号 p. 510-520
    発行日: 1936/12/30
    公開日: 2009/03/19
    ジャーナル フリー
    Weil das zwischen konfrontierten Gewebekulturen geförderte Wachstum der als Cassinotaxis bezeichneten Diffusionserscheinung in Gallerten ähnelt, läßt es sich nach den Vorversuchen in solcher Weise makroskopisch nachahmen. Die Hauptversuche bestehen dagegen in der Nachahmung des Synäreseeffekts der mit Explantaten beschickten Kulturgallerte durcheine auswechselbare Einrichtung zur Behandlungmit Warmluftstrom. Verschiedene mikroskopische (einschl. polarisationsoptischer) Untersuchungen erlauben dabei die Demonstration einer scheinbaren “Fernwirkung” zwischen genügend nahen Wirkungszentren analog dem direktiven Effekt konfrontiert wachsender Kulturen. Die Diskussion berücksichtigt die früheren Versuche mit trocknenden Gallerten, prüft den Geltungsbereich der angestellten Modellversuche und sucht die Ergebnisse für eine Analyse der Vorgänge beim Wachstum von Zellen in vitro auszuwerten.
  • Dyûhei Satô
    1936 年 7 巻 4 号 p. 521-529
    発行日: 1936/12/30
    公開日: 2009/03/19
    ジャーナル フリー
    1) Nerine curviflora (2n=22) has two chromosomes with secondary constrictions and the corresponding two nucleoli in the telophase nucleus.
    Nerine humilis (2n=33) has three chromosomes with secondary constrictions and the corresponding three nucleoli.
    2) Gasteria obscura (2n=14) has four nucleoli of different sizes and the corresponding four satellites and the sizes of the nucleoli are a function of the lengths of the connecting strand of the satellites. Gasteria maculata (2n=28) has eight satellited chromosomes and the corresponding eight nucleoli in the telophase nucleus, but the number of nucleoli decreases as a result of their fusion in the resting and the prophase stages.
    3) Scilla peruviana (2n=16) and S. peruviana var. alba (2n=16) have two satellited S3 chromosomes and the corresponding two nucleoli. S. ughii A-type (2n=17), B-type (2n=19) and Dtype (2n=22) have two S3 chromosomes and the corresponding two nucleoli, while S. ughii C-type has only one S3 chromosome and two nucleoli. On close observation another S3 chromosome translocated to the proximal end of the M4 chromosome (S3-M4) was found in S. ughii C-type. S. permixta A-type has two S3 chromosomes and two nucleoli and B-type has one S3 and one s-M4 ehromosomes and the corresponding one large, and one small nucleoli. C-type has one s-M4 chromosome and one M3-S3 chromosome and the corresponding one large and one small nucleoli. Secondary constrictions which have no relation to nucleoli exist in both Scilla and Haworthia.
    4) The karyotype alteration in Muscari (cf. Delaunay 1926) and the karyotypes of Trillium and Paris (cf. Haga 1934, Matsuura 1935) were explained by translocation in the light of the conception of SAT-chromosomes.
    The writer wishes to express his cordial thanks to Dr. Y. Sinotô for his kind advice and helpful criticisms throughout the course of this work.
  • Seikan Kusunoki, Yoshio Kawasaki
    1936 年 7 巻 4 号 p. 530-534
    発行日: 1936/12/30
    公開日: 2009/03/19
    ジャーナル フリー
  • K. Yasui
    1936 年 7 巻 4 号 p. 535-543
    発行日: 1936/12/30
    公開日: 2009/03/19
    ジャーナル フリー
    1. P. bracteata LINDL. has 14 diploid chromosomes, which make 7 bivalents in the meiotic phase of the PMC. The meiosis in the PMC occurs quite regularly and good healthy pollen grains are formed. Though it shows high sterility when selfed, the crossing inter se results in good seeds. The genom will be denoted by B.
    2. Supposed natural hybrid between P. orientale and P. bracteata or its derivative (No. 41-8) shows similar behaviour of chromosomes in the meiotic phases in PMC to that of artificially raised P orientale×P bracteata and its reciprocals, but the gametes in the latter are highly sterile while those of the former show a higher fertility.
    The somatic chromosome number in these plants is 28, though in some cells of No. 41-8 plant a small fragment chromosome was found in the meiosis. In meiosis of PMC 12, closely jointed, and one loosely jointed, bivalents, and 2 univalents were observed. These univalents divide or not in the lst meiotic division. Irregular behaviour of the chromosomes in the ist and 2nd divisions, namely the formation of diads, triads, extranuclear chromosomes, small Pollen grains, was observed in addition to good healthy looking tetrads.
    3. It is expected that a triploid will be obtained by crossing No. 41-8 with P. bracteata, a pentaploid by crossing P orientale with No. 41-8, and an octaploid by selfing No. 41-8.
    4. P Orientale is a hexaploid plant, and three genoms in its haploid are dissectable, each consisting of 7 chromosomes. Two of them form 7 bivalents in the meiotic phases of the F1 plants of P orientale and P. bracteata, and also in P. somniferum×P orientale and its reciprocal. Six chromosomes in a genom of P. orientale make 6 bivalents with 6 chromosomes in the genom B.
    5. P. orientale may be an autohexaploid, a closely related diploid plant with P. bracteata, but the determination has been postponed until more experimental data are at hand.
    6. There were no homologous chromosomes between P. orientale and P. somnifelum nor between P. somniferum and P. lateritium. In closing the writer wishes to express her hearty thanks to Prof. K. Fuazi by whose suggestion these studies were started, for his valuable advice throughout the course of the work. The expense of carrying out this study was partly defrayed out of a grant from the Foundation for the Promotion of Scientific and Industrial Research of Japan, to the authorities of which the writer's thanks are due.
  • T. Sugiura
    1936 年 7 巻 4 号 p. 544-595
    発行日: 1936/12/30
    公開日: 2009/03/19
    ジャーナル フリー
    Since I published “Cytological Studies an Tropaeolum majus” in 1925, 1 have been continually engaged in the karyological investigation of more than 260 species, covering 82 families, including both Monocotyledons and Dicotyledons (cf. Table 1 in which 81 families, 250 forms including 233 species are listed).
    1) Throughout the present study I have used modified Farmer's fixative exclusively for the fixation of materials of both flower buds and root-tips, and have had favourable results.
    2) I usually found one more or one less chromosome in related plants instead of a polyploidal relation. In some Gases the cause of this seemed to be explained by chromosome fusion during diaphase.
    3) In the plant groups investigated in the present work polyploidy and aploidy are both found. Discussion an these phenomena among others is left until further study an chromosome numbers in many more plants or plant groups has been made.
    4) The chromosome sizes during meiotic and somatic nuclear divisions were measured (cf. Table 1).
    5) True cell plate formation was not observed in the plants used in the present work.
    6) Considering the works of previous authors together with the present Gase it may be concluded that the f urrowing process during the formation of partition wall of pollen mother cells prevails in the Dicotyledonous plants and is found also in some Monocotyledons.
    The expense of carrying out the present study was partly defrayed out of a grant from the Educational Department, and from the Foundation for the Promotion of Industrial and Scientific Research of Japan, to the authorities of which the writer wishes to express his best thanks.
feedback
Top