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MARIKO IKEDA SHIN-ICHI NEMOTO MITSUKI YONEDA 《Development, growth & differentiation》1976,18(3):221-225
The sulfhydryl content of protein and the tension at the surface were measured for starfish oocytes from the first meiotic division to the cleavage stage. A cyclic change in both the protein-SH and the tension at the surface was found to accompany the division cycle, including the first and second meiotic divisions. It is concluded that the unequal meiotic divisions share the same character with the equal divisions of cleavage, with respect to changes both in the protein-SH and the tension at the surface. 相似文献
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Distributions of peroxidase isozymes in various organs of theJapanese morning glory (Pharbitis nil CHOISY) are described.Most peroxidase isozymes had indoleacetate oxidase activity. (Received December 29, 1969; ) 相似文献
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Masahiro YONEDA 《Entomological Science》2008,11(1):123-126
The colony initiation rates of Bombus hypocrita (a native Japanese bumblebee) and Bombus terrestris (a European species) foundresses were compared after 4 weeks of exposure to B. terrestris cocoons. The B. terrestris cocoons, when replaced weekly, were effective for inducing oviposition by foundresses of both species. There were no significant differences in the colony initiation rates of B. terrestris and B. hypocrita, either with the control treatment or with the cocoons. The cocoon method was also tested for five species and two subspecies of native Japanese bumblebees. The colony initiation rate was higher for foundresses of the subgenus Bombus s. str. than for foundresses of the subgenera Pyrobombus, Diversobombus, and Thoracobombus. When replaced weekly, the cocoons of B. terrestris are effective inducers of colony foundation in three Japanese native species, namely B. ignitus, B. hypocrita hypocrita, and B. h. sapporoensis. 相似文献
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对新疆与河北地区野生明亮熊蜂及小峰熊蜂蜂王内寄生螨布赫纳蝗螨Locustacarus buchneri的生物学特性进行了初步观察。结果表明: 该螨对两种熊蜂的寄生率分别为10.43%和8.3%,寄生部位为气管与气囊。室内饲养至30天的蜂王体内寄生螨量明显高于饲养至60天的蜂王。未被螨寄生的蜂王与被寄生者比较,前者体重显著高于后者,但二者间产卵始期、产卵率、食卵率和存活率差异不显著。 相似文献
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Transgenic rice hybrids that carry the Rf-1 gene at multiple loci show improved fertility at low temperature 总被引:1,自引:0,他引:1
By using a genomic fragment that carries the rice (Oryza sativa L.) fertility restorer gene, Rf-1, rice restorer lines harbouring multiple Rf-1 genes on different chromosomes were developed by genetic engineering and crossing. Hybrid lines that were obtained by crossing the restorer lines having two and three Rf-1 genes with a cytoplasmic male sterile (CMS) line had nearly 75 and 87.5% pollen fertility rates under a normal condition, respectively, whereas a conventional hybrid line showed a 50% pollen fertility rate. Furthermore, the seed set percentage under low temperature conditions was much higher in the hybrid lines with multiple Rf-1 genes than the conventional hybrid line. These results indicate that multiplication of the Rf-1 gene conferred cold tolerance at the booting stage to hybrid rice through increasing the potentially fertile pollen grains. This strategy to improve fertility at low temperature of hybrids could be applied to any grain crops that are developed based on CMS and its gametophytic restorer gene, let alone rice. 相似文献
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Interaction between Glucocorticoids and Epidermal Growth Factor In Vitro in the Growth of Palatal Mesenchymal Cells from the Human Embryo 总被引:3,自引:0,他引:3
TOSHIYUKI YONEDA ROBERT M. PRATT 《Differentiation; research in biological diversity》1981,19(1-3):194-198
Previous studies of ours have shown that palatal mesenchymal cells from the human embryo (HEPM cells) are responsive both to the glucocorticoid dexamethasone (DEX) and epidermal growth factor (EGF) through mechanisms associated with cytoplasmic and cell surface receptors, respectively. HEPM cell growth was inhibited by DEX and was stimulated by EGF. In the present study, the interactions between DEX and EGF were investigated. DEX (10–6 M) enhanced EGF-stimulated HEPM cell growth as assessed by an increase in cell number and ornithine decarboxylase activity under serum-free cell culture conditions. DEX also enhanced the specific binding of 125 I-EGF to these cells, which was reflected in an increase in both the number and the affinity of EGF receptors. EGF (1 ng/ml), on the other hand, decreased the number of sites per cell which specifically bind 3 H-DEX. EGF completely prevented the inhibition by DEX of HEPM cell growth. These results indicate that DEX and EGF interact with each other in the process(es) regulating HEPM cell growth. This interaction may be partially influenced by direct modulation of existing receptors for DEX and EGF present in the cells. 相似文献
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PERIODIC CHANGE IN THE TENSION AT THE SURFACE OF ACTIVATED NON-NUCLEATE FRAGMENTS OF SEA-URCHIN EGGS 总被引:3,自引:3,他引:0
MITSUKI YONEDA MARIKO IKEDA SETSUKO WASHITANI 《Development, growth & differentiation》1978,20(4):329-336
Unfertilized eggs of the sea urchin, Hemicentrotus pulcherrimus , were separated into two fragments by centrifugal force. The enucleate fragment (merogone) was subsequently activated by treating it with butyric acid and the tension at the surface was continuously measured by a compression method. The activated merogone was found to exhibit cyclic changes in tension, with a temporal pattern very similar to that of the changes accompanying the division cycle of normally fertilized eggs. This indicates quantitatively the presence in the cytoplasm of some periodic activity which can be triggered without nuclear control. Further, a periodic thickening of the intrahyaloplasmic space of the activated merogone, as noted by K ojima (14), was confirmed on the basis of extended observation. 相似文献
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Indoleacetate oxidase activity in Pharbitis nil, Japanese morningglory, was zymographically examined. Some isozymes appearedonly after treatment with a low concentration of hydrogen peroxide.This phenomenon was assumed to be due to the overlapping ofboth isozymes and natural inhibitor substances on the zymograms.
1Present address: Biological Institute, Department of LiberalArts, Shizuoka University, Ooya 836, Shizuoka, Japan. (Received September 30, 1968; ) 相似文献