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1.
EMI TSUCHIDA AKIKO FUJIWARA YUKIO FUJINO TAKARA YONAGA IKUO YASUMASU 《Development, growth & differentiation》1985,27(1):63-72
During initial several minutes after fertilization, sea urchin eggs exhibited high rate of respiration which was only slightly inhibited by cyanide. This cyanide-insensitive respiration was inhibited by calcium antagonists, diltiazem and verapamil, and calmodulin antagonists, N-(6-aminohexyl)-5-chloro-1-naphthalensulfonamide hydrochloride (W-7), N-(6-aminohexyl)-1-naphthalenesulfonamide hydrochloride (W-5) and chlorpromazine, which were added within 1 min after insemination. The inhibitory effect of W-7 on cyanide-insensitive respiration was higher than that of W-5. Cyanide-sensitive respiration of fertilized eggs observed after this initial period was not inhibited by these compounds. Ca2+ influx in eggs just after fertilization was inhibited by calcium antagonists but was rather enhanced by calmodulin antagonists. Fertilization-induced stimulation of cyanide-insensitive respiration probably results from calmodulin-dependent reactions which are activated by Ca2+ influx. 相似文献
2.
Further studies on the role of cell-wall-degrading enzymes in cell-wall loosening in oat coleoptiles
A fungal endo-ß-l,3-glucanase was compared with afungal exo-ß-1,3-glucanase with respect to their effectson elongation and cell-wall extensibility in oat coleoptilesegments. The exo-enzyme enhanced elongation and extensibilityof the cell wall. Its effect was not additive to the effectof indole-3-acetic acid when given together with the latter,at least during 3 hr of incubation. Endo-glucanase showed nosignificant effect on elongation and no interaction with theexo-enzyme. Auxin and exo-glucanase increased extensibilityof the cell wall. The exo-glucanase was separated by isoelectricfocusing. The two fractions which were separated and showedglucanase activity induced elongation and cell wall loosening. (Received March 16, 1970; ) 相似文献
3.
- It has been established that the absence of isocitric dehydrogenaseactivity in cotyledons of Vigna sesquipedalisin the germinationstage is due to the lack of endogenous TPN. It is unlikely thatthe TCA cycle in the cotyledon is operative.
- The activitiesof enzymes of the glyoxylate cycle, a modifiedTCA cycle, weremeasured through the germination stage. Theiractivities wereconsiderably higher in the cotyledon tissuethan in the hypocotyl.A dominant metabolic pathway of isocitricacid in the cotyledonmay be the glyoxylate cycle.
- DPN kinase which produces TPNfrom DPN, ATP and Mg++ was localizedin the supernatant portionof cell components in the cotyledon.Its activity was low. DPNkinase serves as a control factorfor the cotyledon metabolism.
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5.
KENTARO TAKAGI KARIBU FUKUZAWA† NAISHEN LIANG‡ MASAZUMI KAYAMA MUTSUMI NOMURA HAJIME HOJYO SADAO SUGATA HIDEAKI SHIBATA TATSUYA FUKAZAWA§ YOSHIYUKI TAKAHASHI‡ TATSURO NAKAJI‡ HIROYUKI OGUMA‡ MASAYOSHI MANO¶ YUKIO AKIBAYASHI TAKESHI MURAYAMA TAKAYOSHI KOIKE KAICHIRO SASA YASUMI FUJINUMA‡ 《Global Change Biology》2009,15(5):1275-1288
To evaluate the effects on CO2 exchange of clearcutting a mixed forest and replacing it with a plantation, 4.5 years of continuous eddy covariance measurements of CO2 fluxes and soil respiration measurements were conducted in a conifer-broadleaf mixed forest in Hokkaido, Japan. The mixed forest was a weak carbon sink (net ecosystem exchange, −44 g C m−2 yr−1 ), and it became a large carbon source (569 g C m−2 yr−1 ) after clearcutting. However, the large emission in the harvest year rapidly decreased in the following 2 years (495 and 153 g C m−2 yr−1 , respectively) as the gross primary production (GPP) increased, while the total ecosystem respiration (RE) remained relatively stable. The rapid increase in GPP was attributed to an increase in biomass and photosynthetic activity of Sasa dwarf bamboo, an understory species. Soil respiration increased in the 3 years following clearcutting, in the first year mainly owing to the change in the gap ratio of the forest, and in the following years because of increased root respiration by the bamboo. The ratio of soil respiration to RE increased from 44% in the forest to nearly 100% after clearcutting, and aboveground parts of the vegetation contributed little to the RE although the respiration chamber measurements showed heterogeneous soil condition after clearcutting. 相似文献
6.
TAKUMA TAKANASHI YONGPING HUANG K. RYO TAKAHASI SUGIHIKO HOSHIZAKI SADAHIRO TATSUKI YUKIO ISHIKAWA 《Biological journal of the Linnean Society. Linnean Society of London》2005,84(1):143-160
Sexual communication in many moths occurs between females emitting a sex pheromone and males responding to it. Females of Ostrinia scapulalis (Lepidoptera: Crambidae) show a large variation in blend ratios of the two sex pheromone components (E)‐ and (Z)‐11‐tetradecenyl acetates. E type females produce a pheromone with a high percentage of (E)‐11‐tetradecenyl acetate, whereas Z type females produce the opposite blend. We established laboratory cultures of E and Z types. Females of the F1 generation produced an intermediate blend (I type) in both reciprocal crosses of the E and Z cultures. Results of further crossing experiments suggested that the three pheromone types are primarily controlled by a single autosomal locus with two alleles. Also, analyses of the variation in pheromone blend within F1, backcross and F2 families suggested that other genetic factors modify the pheromone blend of the I and Z types. Investigation of the pheromone variation in natural populations at 14 localities in Japan has shown that the E type was predominant in northern Japan, whereas the pheromone was highly polymorphic in central Japan. At a locality in central Japan, the pheromone was constantly polymorphic for several years, and the pheromone type frequencies did not deviate from Hardy–Weinberg expectations, providing no evidence of selection or assortative mating between the pheromone types. Analyses of pheromone variation within families derived from feral females indicated that matings between a pair with different genotypes for pheromone production was occurring in natural populations. Overall, this study showed that the genetic basis of the pheromone variation in O. scapulalis is very similar to that in its sibling species Ostrinia nubilalis although the state of pheromone polymorphisms in natural populations appears to differ between the two species. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 84 , 143–160. 相似文献
7.
YUKIO FUJINO KEIKO MITSUNAGA IKUO YASUMASU 《Development, growth & differentiation》1987,29(6):591-597
Embryos kept with omeprazole, a specific H+ , K+ -ATPase inhibitor, in a period of development between the mesenchyme blastula and the pluteus corresponding stage became abnormal plutei having quite small spicules, somewhat poor pluteus arms and apparently normal archenterons. In micro-mere-derived cells, kept with omeprazole at pH 8.2 in a period between 15 and 40 hr of culture at 20°C, omeprazole strongly inhibited spicule formation but did not block the outgrowth of pseudopodial cables, in which spicule rods were to be formed. These indicate that omeprazole probably exerts no obvious inhibitory effects other than spicule rods formation. Omeprazole-sensitive H+ , K+ -ATPase, an H+ pump, seems to be indispensable for CaCO3 deposition (formation of spicule rod) in these spicule forming cells. H+ , produced in overall reaction for CaCO3 formation: Ca2+ + CO2 +H2 O°CaCO3 +2H+ , is probably released from the cells by this H+ pump and hence, this reaction tends to go to CaCO3 production to form spicule rods. Omeprazole, known to become effective following its conversion to a specific inhibitor of H+ , K+ -ATPase at acidic pH, is able to inhibit formation of spicule rod at alkaline pH in sea water. This is probably due to an acidification of sea water near the cell surface by H+ ejection in H+ , K+ -ATPase reaction. 相似文献
8.
YOHJI ESASHI YUKIO SAIJOH SATOKO ISHIDA HIROSHI OOTA KIMIHARU ISIZAWA 《Plant, cell & environment》1986,9(2):121-126
Abstract At 23°C, both C2H4 and CO2 stimulated the germination of freshly imbibed upper cocklebur (Xanthium pennsylvanicum Wallr.) seeds, but C2H4, unlike CO2, changed to an inhibitor of germination under some soaking conditions. However, when seeds were pre-soaked for more than several hours at 23 °C prior to treatment, C2H4 strongly inhibited their germination at 33 °C, the degree of inhibition increasing with the duration of pre-soaking. Maximum inhibition occurred at 1–3 cm3 m?3 C2H4 when seeds were pre-soaked for 1 week; further increases of C2H4 concentration and pre-soaking period decreased the inhibitory effect. C2H4 was synergistic with CO2 when C2H4 promoted germination, whereas it was antagonistic when inhibitory. Such a transition of the C2H4 action occurred at ca. 27 °C. Also 1-andnocyclopropane-1-carboxylic acid, a C2H4 precursor, inhibited the germination of pre-soaked seeds at 33 °C, although it promoted the germination at 23 °C. When pre-soaked seeds were prepared for germination by chilling at 8 °C for 3 d, the inhibitory effect of C2H4 on the subsequent germination was manifested even at 23 °C. The reversal of the C2H4 action from promotion to inhibition in cocklebur seed germination is discussed in relation to the engagement of two respiratory pathways in the imbibed seeds. 相似文献
9.
MIYAKO S. HAMAGUCHI YUKIHISA HAMAGUCHI YUKIO HIRAMOTO 《Development, growth & differentiation》1986,28(5):461-470
Movements of polystyrene beads along astral rays of the sperm aster and the mitotic aster were investigated in eggs of the sand dollars, Clypeaster japonicus and Scaphechinus mirabilis . Polystyrene beads injected into the unfertilized egg were at a standstill in the protoplasm. After fertilization, these beads exhibited movements toward the center of the sperm aster along the rays, and finally gathered around the astral center. They were distributed in blastomeres together with the mitotic centers during successive cleavages. When injected into eggs during mitosis, beads moved to the centers of the mitotic asters along astral rays. The injected beads did not move when the aster was disorganized by treatment with Colcemid, and moved when it formed after UV-irradiation. These results indicate that microtubules of astral rays are essential to the movement of polystyrene beads. The movement of small polystyrene beads (0.2–0.3 μm in diameter) resembled the saltatory movement of endogenous cytoplasmic granules, and the movement of large beads (ca. 1 μm in diameter) resembled the female pronuclear migration. All of these movements observed in fertilized eggs were demonstrated to be microtubule-dependent, perhaps sharing the same basic mechanisms. 相似文献
10.
The Wave Pattern of Free Calcium Release Upon Fertilization in Medaka and Sand Dollar Eggs 总被引:4,自引:4,他引:0
YASUAKI YOSHIMOTO TAKASHI IWAMATSU KEN-ICHI HIRANO YUKIO HIRAMOTO 《Development, growth & differentiation》1986,28(6):583-596
A transient rise in the concentration of Ca2+ in the cortex upon fertilization was demonstrated in medaka eggs injected with aequorin. Detection of the aequorin luminescence with an ultra-high sensitivity photonic microscope system revealed a wave of increased Ca2+ concentration starting at the site of sperm entry (animal pole) and being propagated along the cortex of the egg toward the antipode. The wave traversed the entire egg surface within 2–3 min. The peak value of the aequorin luminescence, and therefore the peak value of the Ca2+ transient, was generally higher at the site of sperm entry than in other regions. The peak values of the luminescence (and therefore of the Ca2+ concentration in the cortex) remained fairly constant during propagation of the wave. Microinjection of Ca2+ into the cortex also induced a Ca2+ wave. When the egg was stimulated by microinjection of Ca2+ at the equatorial region, the Ca2+ wave was propagated at a fairly constant speed over the egg surface, except at the region near the vegetal pole where the wave was retarded. Simultaneous recording of the Ca2+ wave and the wave of cortical change (breakdown of cortical alveoli) in eggs during fertilization revealed that the Ca2+ wave preceded the wave of cortical change.
A Ca2+ wave was also demonstrated in sand dollar eggs, although due to their smaller size the phenomenon was not as clear as in medaka eggs. 相似文献
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