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41.
Megumi Fujisue Masao Sakai Kiyotaka Yamanat 《Development, growth & differentiation》1991,33(4):341-351
The specification of the dorsoventral axis in naturally polyspermic eggs of the Japanese newt, Cynops pyrrhogaster , was first examined by studies on the spatial relationship between the dorsal midline of the future body plan and the sperm entrance points (SEPs 1 ). On local insemination, the dorsal blastopore lip was usually found to be formed opposite the SEPs, as in anuran monospermic eggs. Next the movements of the subcortical layer and the cortex were analyzed. "Subcortical rotation" was observed, similar to that of Xenopus laevis eggs with respect to its timing and extent, and its direction was shown to predict the embryonic axis of the eggs. Thus, the dorsoventral axis was concluded to be determined by essentially the same mechanism in the newt as in Xenopus .
Owing to their large size and long first cell cycle, newt eggs appear to be suitable material for study of subcortical rotation, but their behavior is unique in that subcortical rotation occurs in only the vegetal hemisphere so that the subcortical layer stretches in the future dorsal side. Studies on the movement of Nile blue spots suggested that the cytoplasm under the cortex in newt eggs consists of two layers. 相似文献
Owing to their large size and long first cell cycle, newt eggs appear to be suitable material for study of subcortical rotation, but their behavior is unique in that subcortical rotation occurs in only the vegetal hemisphere so that the subcortical layer stretches in the future dorsal side. Studies on the movement of Nile blue spots suggested that the cytoplasm under the cortex in newt eggs consists of two layers. 相似文献
42.
Minoru Takagi Masao Maeno Yasuki Takahashi Kichibee Otsuka 《The Histochemical journal》1992,24(2):78-85
Summary The present study utilized biochemical and immuno-and lectin-histochemical methods to demonstrate solubility and retention of mineral-binding non-collagenous proteins in rat midshaft subperiosteal bone during EDTA demineralization. A monoclonal antibody (9-A-2) specific for chondroitin 4-sulphate and dermatan sulphate and wheat germ agglutinin (WGA) specific forN-acetyl-d-glucosamine,N-acetylneuraminic acid, andN-acetyl-d-galactosamine were used. Bone proteins were extracted from fresh unfixed or aldehyde-fixed specimens with a three step extraction procedure, 4 M guanidine HCl (GdnCl), aqueous EDTA without GdnCl, followed by GdnCl. For comparison with the second extraction step, ethanolic trimethylammonium EDTA (ethanolic EDTA) was substituted for aqueous EDTA. Based on protein staining and Western blot analysis of SDS-polyacrylamide gel electrophoresis of each extract using 9-A-2 and WGA, retention of mineral-binding proteins extractable from fresh specimens with aqueous EDTA was greatly increased in tissue when ethanolic EDTA was used. Their retention was even greater with prior aldehyde fixation. Maximum retention with no detectable solubility of 9-A-2 and WGA reactive proteins was obtained after ethanolic EDTA extraction of aldehyde-fixed specimens, which concomitantly provided the strongest immuno- and lectin staining. These results indicate that this combined method dramatically improves retention of PGs and glycoproteins during demineralization of bone tissues and provides the best method for localizing these glycoconjugates. 相似文献
43.
Kuriyama Akira; Takeuchi Masayuki; Kawai Fumio; Kanamori Masao 《Plant & cell physiology》1992,33(5):647-650
The formation of sporophytic shoots, which is induced by treatmentwith benzylaminopurine of gametophyte tissue of Equisetum arvense,can be divided into initiation and developmental phases. Thenitrogen in MS medium was suitable for two phases as well as gametophytic growth, buta reduction in the concentration of available nitrogen was neededfor the development of shoots. ions alone were effective for gametophytic growth and the initiationof sporophytic shoots, but both and ions was required for the developmental phase. (Received February 18, 1992; Accepted April 14, 1992) 相似文献
44.
The methods of primary culture and cryopreservation of mouse astrocytes under serum-free conditions were examined. Cerebra from newborn C3H/He mice were employed as the source of astrocytes. The cultured cells were able to grow in a serum-free, chemically defined medium containing transferrin, hydrocortisone, biotin, sodium selenite, insulin, fibroblast growth factor and epidermal growth factor. After the culture was maintained in the medium for 3 weeks, purity was assessed using immunofluorescence staining. The great majority of the cells (>98%) contained glial fibrillary acidic protein and S-100 protein which are cell markers of astrocytes. To cryopreserve the enriched astrocytes under serum-free conditions, various cryoprotectants were examined. The combination of 10% dimethylsulfoxide and 0.1% methylcellulose gave the highest survival rate. These methods of primary culture and cryopreservation will be useful in physiological and biochemical studies which require mouse astrocytes. 相似文献
45.
Masamitsu Honma Eiko Kataoka Kiyokata Ohnishi Tadao Ohno Masao Takeuchi Nobuo Nomura Hiroshi Mizusawa 《In vitro cellular & developmental biology. Animal》1992,28(1):24-28
Summary Using the polymorphic DNA probes, ChdTC-15, ChdTC-114, pYNH24, and λTM-18, a DNA profiling system was developed that verified
identities of individual cultured cell lines collected in the Japanese cell banks, JCRB, RCB, and IFO. These highly polymorphic
DNA probes include both VNTR (Variable Number of Tandem Repeats) sequences and substantial lengths of unique regions. In the
mixed probe system, several distinct bands from four to eight can be used for cell line identification. These bands were widely
spread in a range of molecular sizes, and were stable and reproducible under stringent conditions of Southern blot hybridization.
Because the DNA profile was specific for each individual human cell line, it is useful not only to authenticate many existing
cultured cell lines but also to monitor their identity during propagation in a laboratory, and to confirm newly established
lines as unique. 相似文献
46.
Controlled alkaline hydrolysis of 16α-bromo-17-keto steroids , and with potassium carbonate and tetra-n-butylammonium hydroxide (n-Bu4NOH) and synthesis of 2α-hydroxy-3-ones , and by the controlled hydrolysis of the corresponding 2α-bromo-3-ones , and are described. Treatm carbonate in aqueous acetone or with n-Bu4NOH in aqueous dimethylformamide (DMF) gave 16α-hydroxy-17-ones , and in 85–90% yield, respectively. 2α-Hydroxy-3-ones , and were obtained by hydrolysis of the corresponding bromoketones , and in high yields using the above conditions or sodium hydroxide in pyridine or DMF, respectively. Deuterium labeling experiments suggested that equilibration between the 2α-bromoketone and the 2β-bromo isomer precedes the formation of the ketol in which the true intermediate might be the 2β-isomer . However, rearranged androstane derivatives, 3β-hydroxy-2-ones and , were stereoselectively obtained by treatment of the bromoketones and with an excess amount of sodium hydroxide. 相似文献
47.
Hiroshi Hayakawa Kanji Ishizaki Masao Inoue Takashi Yagi Mutsuo Sekiguchi Hiraku Takebe 《Mutation research》1981,80(2)
DNA-repair characteristics of xeroderma pigmentosum belonging to complementation group F were investigated. The cells exhibited an intermediate level of repair as measured in terms of (1) disappearance of T4 endonuclease-V-susceptible sites from DNA, (2) formation of ultraviolet-induced strand breaks in DNA, and (3) ultraviolet-induced unscheduled DNA synthesis during post-irradiation incubation. The impaired ability of XP3YO to perform unscheduled DNA synthesis was restored, to half the normal level, by the concomitant treatment with T4 endonuclease V and ultraviolet-inactivated Sendai virus. It is suggested that xeroderma pigmentosum cells of group F may be defective, at least in part, in the incision step of excision repair. 相似文献
48.
Yoshinori Asakawa Masao Toyota Reiji Takeda Claude Suire Tsunematsu Takemoto 《Phytochemistry》1981,20(4):725-728
Riccardia species (Metzgeriales) contain various types of sesquiterpenes. R. jackii produces ent-selinane-, ent-aromadendrane-and ent-bicyclogermacrane-type sesquiterpenes together with (R)-cuparene and α-barbatene. Aneura pinguis (= Riccardia pinguis) is chemically quite different from R. multifida and R. jackii. The former produces a large amount of pinguisone. R. multifida contains 6-(3-methyl-2-butenyl)-indole and (+)-β-elemene as the major components. Pallavicinia longispina (Dilaenaceae; Metzgeriales) produces mainly spathulenol. The chiral properties of the sesquiterpenes isolated from R. jackii are quite similar to those of red algae, Laurencia species. 相似文献
49.
A new bibenzyl having a dihydrooxepin ring was isolated from the acetone extract of the liverwort Radula tokiensis, together with the previously known 5 bibenzyls and 3 sesquiterpenes, trans-β-farnesene, cuparene and (Jcuparenol. Two known bibenzyls were isolated from R. japonica. The bibenzyl derivatives are significant chemosystematic markers of the Radulaceae. 相似文献
50.
Cells ofClosterium ehrenbergii expanded for about 4.5 hr after vegetative cell division and about 3 hr after sexual cell division. Short cells were produced by the sexual expansion. At the early stage of the vegetative and the sexual expansion, most microfibrils were deposited transversely to the cell axis on the inner surface of the new wall. Then, bundles of microfibrils, running in various directions, overlaid the transverse microfibrils already deposited, at the late stage of the both types of expansion. The pattern of microfibril deposition changed from the transverse to the bundled pattern about 4 hr after the vegetative and about 2 hr after the sexual cell division, respectively. The change of pattern of microfibril deposition seemed to be highly correlated with cessation of cell expansion. 相似文献