The chromosome numbers were counted in 47 species and varieties belonging to 25 genera oft he family Gramineae. Four genera, Arundinella (n=9), Fingerhuthia (n=10), Harpechloa (n=10) and Trichopteryx (n=12) were previously unknown cytologically. Eighteen species and varieties belonging to various genera were studied cytologically for the first time. In addition eight species and varieties studied are characterized by chromosome numbers differing from earlier reports. Cytological and anatomical data suggest that Fingerhuthia occupies an aberrant position in the tribe Festuceae and should be removed from the subfamily Festucoideae. It was indicated that this subfamily is far from homogeneous. The genus Aristida differs from other members included in the subfamily Eragrostoideae in cytology and leaf anatomy.
1) It was shown that megasporogenesis of Trillium kamtschaticum Pall. took place, as in other species of Trillium, after Allium-type. 2) A method of analysis of the mode of disjunction of bivalent chromosomes at the first meiotic anaphase was described with “half tetrads” of the EMCs of this plant. 3) The “half tetrad” analysis was carried out with ten individuals having heterozygosity in differential segments of chromosomes. There could be found no post-reductional disjunction among thirty-one heterozygous chromosome pairs detected in these individuals,
1) Abnormal stomata, which appeared in the variegated leaves of cytoplasmic male-sterile durum plants were investigated cytologically and classified in six types according to two criteria, namely; degree of differentiation of guard cells and their nuclei, and abnormality or deficiency of subsidiary cells. 2) Observation on the cross-section of variegated leaves revealed that the inner air space of the abnormal stomata was smaller than that of normal stomata and that palisade cells in the variegated portion were rather round and arranged irregularly. 3) The frequency of occurrence of abnormal stomata was investigated. The percentage of abnormal stomata in the variegated portion reached as high as 38%, but the mean value in the variegated leaf was 12% in longitudinal and 9% in transverse directions. Mature leaves of male-sterile plants do not have abnormal stomata any longer (only 0.2% of the stomata was abnormal). 4) Alteration of stomatal distribution was observed in the variegated leaves, that is; the average number of stomata per unit length is decreased in longitudinal direction and is increased in transverse direction, as compared to the number found in normal green leaves. 5) It was ascertained from the x2-test that abnormal stomata did not occur at random in the variegated leaf, but occurred serially to a certain degree and that more series were found in longitudinal than in transverse direction. 6) Cell length and nuclear length of guard cells in the variegated leaf varied widely and decreased in comparison with those of the normal green leaf. On the other hand, some subsidiary cells were increased in length (although the mean value of cell length was decreased). Width of cell and nucleus did not change to the same degree. 7) A correlation between cell length and nuclear length of guard cells was found expressed by a correlation coefficient as high as +0.9137. 8) The data presented lead to the assumption that an unknown cytoplasmic factor induces abnormal metabolism in winter leaves, leading to abnormal development of stomata, and on the other hand, to formation of abnormal chloroplasts. The abnormal stomata seem to accelerate the chlorophyll variegation. The present author wishes to express his cordial thanks to Dr. H. G. duBuy, National Institute of Allergy and Infectious Diseases, U.S.A., who was kind enough to read over the manuscript and make some corrections in the style.
That ultraviolet-induced respiratory deficiency in Saccharomyces was photoreversible implicated the nucleus as the site of radiation damage; further, the fact that only the induction of variants in respiration adapted cells was photoreversible supported the primary conclusion drawn from this work that the induction of respiration deficiency resulted from damage to a nuclear entity involved in the adaptive formation of respiratory enzymes. Unlike the photoreactivation of induced respiration deficient variants, photoreactivation of inactivational damage was independent of the state of cellular adaptation to respiration. This, together with the observation that the expression of ultraviolet damage resulting in the production of respiration deficient variants was completely determined by post-irradiation respiratory conditions while the expression of inactivational damage was only partly so determined, revealed that cellular inactivation and the induction of respiratory variants involve different nuclear disturbances. This paper presents the first experimental challenge to the hitherto accepted concept that non-segregational, respiratory deficiency in Saccharomyces is cytoplasmically inherited.
1) Three types of accessory chromosomes, E, e and ee were found in Lilium medeoloides A. Gray. Their maintenance in mitotic tissue was complete since little few intra-plant variation in their number and size was detected. 2) Meiotic disjunction of the accessory chromosomes was often irregular conditioned by a) their mode of conjugation, b) their position in spindle apparatus at MI, and c) their size, the small size being defective in anaphase disjunction. 3) Fifteen different karyotypes were distinguished with respect to the number and type of these accessory chromosomes among 117 individuals obtained from nine aggregates of this plant. Adding to these, one triploid plant, which did not include any accessory chromosomes, was found. 4) All the plants obtained from three aggregates had no accessory chromosomes and, therefore, their karyotype was fixed, being 2n. Only one type of accessory chromosome, E, was found in one of the aggregates examined. The remaining aggregates included different types of accessory chromosomes in various combinations both in number and kind. 5) Mapping of individuals bearing flower buds was made at two localities where an aggregate of this plant was chosen for investigation. Active sexual reproduction was confirmed in one of the two which was the most polymorphic in karyotypic constitution. In another, which included no accessory chromosomes and accordingly revealed no karyotypic variation decline of sexual propagation was inferred.
A thorough study of the karyotypes has been performed on fourteen different species and varieties of Jasminum in order to fill this lacuna in our knowledge of the cytology of this genus. Improved techniques, involving the use of Aesculine, have been standardized for this purpose. The absence of any detailed study on this aspect has been attributed mainly to the limitations of the methods adopted previously. A general resemblance has been noted in the chromosome morphology between species of Jasininum, indicating that the genus represents a natural assemblage. The different species and varieties have been found to differ from each other in minute details of the karyotype. This fact has been regarded to suggest the important role played by structural alteration of chromosomes in evolution. As each and every species or variety is characterized by a distinct karyotype, the significance of this study in the identification of species has been emphasized. The minor part played by polyploidy and specially, allotetraploidy, before the species concerned lost its capacity for sexual reproduction, has also been pointed out. Variation in chromosome complements has been noted in the same somatic tissue containing normal nuclei and, as sexual propagation is mostly ineffective in this genus, the role of such somatic mutations in speciation of this genus through asexual means has been suggested.
Unfertilized Arbacia eggs were used for a study of viscosity changes under suppressed respiration by the inhibitor sodium azide, or by nitrogen substituted for oxygen in the medium. The width of the clear zone produced by centrifugation of treated and control eggs was taken as an index of the cytoplasmic viscosity. Azide produced a conspicuous rise in viscosity within 15 minutes of treatment. Eggs placed in sea water with Nitrogen substituted for Oxygen took several hours before a similar rise in viscosity took place. When treated eggs from both azide and N2 vessels, were washed and returned to sea water, they regained normal viscosity; they were also fertilizable indicating no permanent change during treatment. It was concluded that oxidative energy is required for maintenance of protein structure in living cells.
1. The taxonomic position and history of C. Brownei has been described and compared with C. saltiana. 2. The somatic chromosome number of C. Brownei has been determined to be 16, which is reported for the first time. 3. The mitosis of the two species has been studied and their karyotypes analysed on the basis of morphology and length of the chromosomes and the position of the centromere. The differences between the two species have been pointed out. 4. The identification of C. Brownei as separate taxonomic species has been confirmed on cytological evidences and it is suggested that the species should not be merged with C. saltiana. 5. It has been further suggested that C. Brownei, is a relatively primitive species as compared to C. saltiana.
1. Chromosome numbers of five species of Oxalis, one species of Biophytum and two of Averrhoa jave beem determined from pollen mother cells during meiosis. They are n=24 in Oxalis pubescens and O. corniculata, n=14 in O. pes-caprae and O. violacea, n=28 in 0. teti-apIlylla, n=9 in Biophytum sensitivum, and n=11 in Averrhoa bilimbi and A. carambola. 2. All the species of Oxalis studied were polyploids on the basic numbers 6 and 7. From a review of all the cytological data on the genus it is seen that 5, 6, 7, 9 and 11. are the basic chromosome numbers in Oxalis, 7 being the most frequently occurring number. Biophytum and Averrhoa have 9 and 11 respectively as their basic numbers. 3. Affinities of the family are briefly considered in the light of cytological findings. Oxalidaceae is suggested to be more closely related to Geraniaceae. 4. Polyploidy, side by side with considerable change of basic chromosome numbers, is suggested to have been responsible for the evolution of a large number of species in Oxalis, while polyploidy and change of basic numbers are absent in Averrhoa.
The present study deals with a comparison of the chromosomes between the Yoshida sarcoma subline A and its single-cell clone. It was found that the single-cell clone here established and the original tumor were similar in their chromosome pattern. The cytological similarity between the single-cell clone and the original tumor may be attributable to the facts that the neoplastic population of the Yoshida sarcoma subline A is characterized by stemline cells of a certain genotypic constitution, and that the original tumor and its single-cell clone are genotypically as well as chromosomally identical, since they have originated from the stem-cells of a similar genotype. The authors wish to express their sincere thanks to Professor S. Makino for his kind direction and improvement of this manuscript for publication. Further cordial thanks are offered to Mr. T. Tanaka and Mrs. K. Kanô for their valuable advices and technical guidance.
The effects of cortisone administration and of long-term fasting on liver cells of rats were studied cytochemically following the applications of the acid hematein test for the demonstration of phospholipids, the periodic acid Schiff reaction for glycogen, and the Regaud's method for staining the mitochondria. Special attention was paid to the relation between the stainability by acid hematein of the mitochondria and on their morphology under experimental conditions. The stainability of cytoplasmic constituents, probably mitochondria, after the acid hematein test seemed to be closely associated with the morphology and the chemical constitution of the mitochondria. The mitochondria of a fine-spun form caused by the cortisone administration were not stained with acid hematein, although they were rendered detectable by means of Regaud's method of staining. With the above exception, there is shown, in respect to staining features of the liver cells, a similarity between Regaud's method and the acid hematein test. The mitochondria of the cortisone liver showed reduced affinity to acid hematein as compared with those of the normal liver. The author wishes to offer his sincere thanks to Professer S. Makino for his kind guidance and for his improvement of this manuscript for publication.
The effects of various amino acids, ethylenediaminetetraacetic acid (EDTA) and diethyldithiocarbamate (DDC) on the motive force of protoplasmic streaming in the plasmodium, Physarum polycephalum, were investigated by means of Kamiya's double-chamber method. The following results were obtained. 1. The motive force increased with the treatment with histidine, cysteine and glycine. This increase was greatest in histidine, greater in cysteine than in glycine. These processes were reversible. 2. Other amino acids induced no marked effects on the production of the motive force. 3. EDTA inhibited the generation of the motive force to a certain extent. This inhibition was not removed by the elimination of the reagent. But, when Mg++ was admitted after the removal of EDTA, the motive force not only recovered, but rather increased as compared with its original state. 4. DDC suppressed the motive force. No marked recovery was obtained by the addition of Mg++ in this case. 5. It has been suggested that the induced increase of the motive force by amino acids may be due to the release of some metal (perphaps zinc) from the plasmodium.