Immunochemical and biochemical studies were carried out on the polysaccharides of Shigella flexneri in which phage mediated conversion of the type antigen had been observed. Descending and ascending paper chromatography was carried out to confirm the constituent sugars of the polysaccharides. The polysaccharides consist of glucose, galactose, heptose (?), hexosamine and N-acetylhexosamine. Quantitative determinations of sugars in the polysaccharides of the strains 1a, 2a, 3a, 4a and VX were carried out. Methylpentose, galactose and pentose were present in approximately the same ratios in all polysaccharides, but hoxosamine and glucose were detected in various ratios. The ratio of hexosamine to glucose is 1:1 in 1a and 2a, 3:4 in 3a, and 2:1 in 4a and VX. The amount of acetyl group is approximately similar to the amount of hexosamine, however in 3a polysaccharide O-acetyl group was also detected. Stability of various antigens of the polysaccharides against acid and alkali was compared. Antigenicity of the type antigen III was very sensitive against alkali. The antigenic determinants of the group antigens 3, 4 and 6 would be N-acetyl-D-galactosamine, and the antigenic determinants of 7, 8 would be α-glucosyl-(1→4)-_??_glucose or N-acetyl-D-galactosamine_??_-which is similar to those of the type antigens I, II and IVI.
Supernumerary and deficiency of the antenna are found to occur frequently in lines of Drosophila melanogaster which show a hereditary deficiency of compound eyes. The two types of antennal irregularity were shown to be a hereditary character. The same type of the irregularities are generally reproduced, but there are a few cases in which different types are produced. It was shown that these antennal irregularities are inherited always in accompany with the deficiency of compound eyes, no case being found in which the irregularities are reproduced without accompanying the eye-deficiency.
A fertile branch with a constant hypotetraploid chromosome number was produced on an extremely unstable aneusomatic hybrid of Solanum melongena var. pumilo×S. integrifolium F1. Stabilization of the chromosome number was accompanied by restoration of normal external appearance. In the F2 generation raised from the seeds of the changed branch, segregation was noticed both in the vegetative habit and in the chromosome number. Two types of chromosome number, 2n=48 and 2n=47, were observed in the F2 plants.
The frequency of polyploid tumor cells invading the lung of mice bearing Ehrlich hyperdiploid tumor (ELD) was reinvestigated by the organ graft technique. Pieces of lung tissue from mice bearing ascites tumors (containing 13 percent polyploid cells) were injected into the peritoneal cavities. The ascites tumors thus developed had 73.4 percent polyploid cells, while the control ascites tumors had only 11 percent. The experiment was repeated with another Ehlich tumor strain contatning only 2 percent polyploid cells. Ascites tumors, developing in two mice after lung tissue transplants, contained 26.7 and 28.1 percent, respectively, though control ascites tumors had 2.5 percent. To explain this phenomenon, two experiments were carried out: 1) ELD tumors containing only 0.2 percent polyploid cells were inoculated into the tail veins. Three metastatic tumors thus developed had 61.9, 40.4 and 17.9 percent polyploid cells, respectively, while the control animals had only 0.4 percent. 2) About 100 ELD tumor cells were injected directly into the brain, liver and under the skin to ascertain the difference, if any, in the occurrence of polyploid cells. No increase of such cells was observed in tumors developing after direct inoculation. From these experiments, cause of the increase of frequency of polyploid cells in metastatic tumors was discussed.
Chromosomes of dwarf female cattle were observed in comparison with those of normal females and males. Normal as well as dwarf female cattle had 60 chromosomes, namely 29 telocentric autosome pairs and one submedian metacentric X pair. There was no difference in thh karyotype between normal and dwarf cattle. Male normal cattle had 29 telocentric autosome pairs and in addition a submedian X and a median metacentric Y chromosome. From the above investigation, it was considered that the character of dwarfism is not reflected in the karyotype being due to a sigle autosomal gene mutation.
Avena barbata (2n=28, AAB'B') was crossed with a fatuoid heterozygote (2n=41, AABBCC-c) of A. sativa which is monosomic for the c-chromosome carrying both factors for the cultivated type grain character and normal synapsis, and the two types of the F1 plants, i. e. 35-chromosome plants (AABB'C) and 34-chromosome plants (AABB'C-c), were compared in their morphological characteristics and chromosome pairing. The 34-chromosome plants were shorter in plant height and showed the wild grain character, owing to the deficiency of the c-chromosome. In regard to chromosome pairing, no significant differences were found between the two types in the average number of pairs or of chiasmata per cell at metaphase I. It demonstrates that the meiotic pairing between the homologous chromosomes from the two species can take place in the absence of the synaptic factor of A. sativa, as the chromosomes are paired probably in the presence of the synaptic factor(s) of A. barbata.
In the PMCs of Trillium kamtschaticum, the frequencies of the combinations of two chromosomes which participate in an exchange were investigated with several materials irradiated at various stages of the meiotic prophase. In the materials irradiated in late October, the observed frequencies in the various combinations were roughly in accord with their expected values calculated on the basis of the proportionality to chromosome length and the random distribution of chromosomes in a prophase nucleus. On the contrary, in the cases irradiated later than the end of October, certain greater deviation from the expectation was demonstrated. Comparing the relative frequencies of the exchanges between homologous chromosomes, it was clearly shown that the values decrease in the cases of irradiation at November, December, and January of the next year. These results may be taken to indicate that chromosome pairing takes place later than October in the PMCs of this plant.
The inheritance of BHC-resistance in the Indian housefly, Musca domestica nebulo was studied by making reciprocal crosses between individual as well as groups of flies of a BHC-resistant and a susceptible strain of the subspecies. The F1 generation was less resistant than the resistant parents but far more resistant than the normal ones and there was no segregation in the F2 generation. The F1 hybrids were also back crossed with susceptible parents but no evidence for a monofactorial origin of resistance could be found. The validity of the results when checked by the formula of Castle (1921a, 1921b) led to the conclusion that BHC in M. d. nebulo is polygenic in origin.
I. H-h alleles. In the presence of ss, the H gene reveals the white spot on the head or face, while its recessive allele h reveals the white spot on the lumbar or back. This assumption has been obtaines from the following experiments.
The vegetative propagation, CO2 production and water content of the bulbs favorable for induction of bud mutations were examined. The results are summarized as follows: The floral organ which will give a flower in the first spring is formed in mid-November, and at the same time, the main bud which will flower in the second season is indicated by 2-3 scales. The growing point which will give a flower in the third spring, is differentiated inside those scales during the first spring. The bulbils did not have flowers if they grew up to be less than 8cm in circumference. In the previous paper, the irradiation was carried out mostly during September to November, and the color sporting of petals was observed during four successive vegetative generations after irradiation. This procedure explains the previous results; i. e., the tissues of the tulip bulb mentioned above, namely, the floral organ, the main bud and the growing point were irradiated at the same time, and consequently it appears that a change induced in the floral organ will appear in the first spring and a change induced in the main bud or the growing point will appear in the flower of the second or third spring respectively. CO2-production of tulip bulbs during 120 days of starage was measured by the gas flow method and the value of 4-10×10-3mg/1g fresh wt/1hr was obtained, which approaches that obtained from dry seeds of other plants. The greater susceptibility of tulip bulbs to radiation is probably due to their greater water content, which, in this experiment, was determined to be 56-58%.
The influence of acute and chronic irradiations on the growh of tulip plants was examined. The bulbs of two varieties, Diana (diploid) and Keizerskroon (triploid), were irradiated in two ways; namely, by 1kr in total amount with doses varying between 10 and 200r/h, and by chronic 6.8r/h irradiation the total amount varying between 2 and 8kr. The effects on plant growth, measured in terms of stalk length, flowering, survival, and bulbil yield were examined in the first vegetative season. The results are summarized as follows; 1) The total dosage required to produce severe growth inhibition was 1kr at acute irradiation with doses of 100 to 200r/h. On the other hand, at chronic irradiation with 6.8r/h, a larger total dosage, determined to be 8kr, was necessary to get the same effect as at acute irradiation. 2) Some differences in radiosensitivity were found in the two varieties, i. e., judging from 1kr total irradiation with doses varying between 10 and 200r/h, the diploid was more susceptible than the triploid variety in all responses examined, but there was little difference in radiosensitivity at chronic exposure to 6.8r/h. 3) The total weight and the total number of bulbils which formed the floral organ were reduced with increasing dosage, while the over-all number of bulbils was not much affected but rather showed an increase. Some difference was noted between the varieties when the yield was reexamined as to bulb size. These results show that although a general statement cannot be made, because the irradiation effect is modified by recovery and storage effect in the case of chronic irradiation, nevertheless it is estimated that acute irradiation is several times more effective than the chronic one. According to a previous paper, the differences in radiosensitivity among varieties to acute and chronic exposure will be due rather to the growth rate of tissue during irradiation than to ploidy itself. In the case of the bulbil yield after irradiation, the nutritional factors also were considered, falling into two categories; the influence of the relative growth of the mother plant (stalk length, etc.) on the bulbils; and the competition among the bulbils themselves.
The air-drying technique described here was modified to facilitate the analysis of chromosome complements in cells of a solid tumor. The procedure of chromosome preparation was as follows: Thoroughly wash the material in balanced salt solution, and mince on a watch glass as well as possible. Suspend in hypotonic solution (1:3 of Hanks and dist. water) for 20min at room-temperature. Centrifuge at 200 rpm for 2min, and take off the coarse precipitate. Centrifuge at 800rpm for 5min, and discard almost supernatant, leaving a small volume of supernatant in a centrifuge bottle. Resuspend cells gently. Put a centrifuge bottle in iced water, then add cold Carnoy's fluid very slowly. Leave for 30min in iced water. Centrifuge at 800rpm for 10min. Decant and suspend in about 0.5 to 1ml of ice-cold Carnoy's fluid. Drop on to wet slide (keeping in 50% of cold alcohol) from a fine pipettte. The drops should be very small. Spreading may be accelerated by blowing. Dry quickly over a spirit flame. Stain with 0.75% dahlia in 30% acetic acid for 1 to 2min. Rinse with distilled water, and mount. The method described above achieves a fairly uniform and complete flattening of metaphase figures in cells of a solid tumor of which it is difficult by manual squashing.
1. In the present report, the external characteristics, fertility and the meiosis in PMC's of F1 (TperR perH F1) plants and the external characteristics, fertility and the somatic chromosomes of F2 plants raised from Triticum persicum-Secale cereale amphidiploid (TperR) and T.persicum-Haynaldia villosa amphidiploid (TperH) were described. These F1 and F2 plants were obtained in 1961 and '62 respectively. 2. Hybridization was successful in producing trigeneric F1 in crossing TperR amphidiploid with TperH amphidiploid, but it failed in crossing TperH with TperR (Table 1). 3. The number of somatic chromosomes of the trigeneric F1 hybrids were 42 in 25 individuals and 41 in 5 respectively. The number of chromosomes, 42, corresponds exactly to the sum of the gametic number of these parental plants. 4. At the heterotypic metaphase on meiosis of PMC's of F1, 12-15 bivalents were observed (Figs. 5-11, 13-18). The frequency of the bivalents in one PMC was shown in Table 3. Almost all the bivalents consisted of two elements of equal size, but in very rare case, heteromorphic bivalent was observed. Most of the bivalents were ring-shape conjugated closely, though some of them were stickshaped. The case of 14II appeared to be the mode in every F1 plant (Table 3). It is thought that 14 of the 15 bivalents may be due to autosyndesis of the chromosomes of AB genomes of Triticum persicum derived from both parents, and the remaining one riled from autosyndesis of V or R genome, considering the results of cytological research on the intergeneric hybrids between Triticum, Secale and Haynaldia and one the haploid plant of Secale by Kostoff (1937), Nordenskiöld (1939) and Nakajima (1951, '56, '57, 'S9). 5. Trivalent was observed occasionally, in addition to bivalents at the heterotypic metaphase, and tetravalents were very rare. 6. As the anomalous PMC's, the large PMC having 2 nuclei, the giant PMC having 4n chromosomes (No. 11, 2n=41) and the many smaller PMC's having lesser chromosomes such as 2II+5I (Fig. 18), 3II+16I, 4II+17I, 5II+12I and 6II+12I and many others were observed. They may be thought of as caused by the anomalous division not of PMC but of archesporial cells of these F1 plants. 7. Most of the individuals of TperRperHF1 were almost fertile, though partial, and some anthers opened and some grains were obtained in natural selfing (Table 2) and by sowing them in October 1962, 63 matured F2 plants were raised. The number of somatic chromosomes of these F2 plants was found to vary from 21 to 54 (Table 7). 8. 12 individuals of 35 F2, the external characteristics of which were observed, showed fertility while others were completely sterile (Table 9). And as the total number, 562 grains were obtained from these 12 F2 plants, and a part of them were sown in October 1963 and many F3 plants were obtained.