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 共查询到13条相似文献,搜索用时 93 毫秒
1.
李明文  刘辉 《动物学报》1997,43(1):80-84
用焦锑酸钾原位定位法、膜结合Ca^2+荧光探针金霉素标记法,分别在电镜和光镜水平对小鼠卵成熟和卵受精过程中结合态Ca^2+的分布及其变化进行了研究,发现:1)Ca^2+分布于线粒体、胞质、内质网囊泡、微绒毛和透明带等部位,其中以线粒体基质中分布密度为最大;2)减数分裂I中、后期于纺锤体极区结合有较多的Ca^2+;3)生发泡、纺锤体和原核内膜结合态Ca^2+含量很少,但纺锤体和原核周围分布较多;4)  相似文献   

2.
Cell proliferation is accompanied with changing levels of intracellular calmodulin (CaM) and its activation.Prior data from synchronized cell population could not actually stand for various CaM levels in different phases of cell cycle.Here,based upon quantitative measurement of fluorescence in individual cells,a method was developed to investigate intracellular total CaM and Ca^2 -activated CaM contents. Intensity of CaM immunoflurescence gave total CaM level,and Ca^2 -activated CaM was measured by fluorescence intensity of CaM antagonist trifluoperazine (TFP).In mouse erythroleukemia (MEL) cells,total CaM level increased from G1 through S to G2M,reaching a maximum of 2-fold increase,then reduced to half amount after cell division.Meanwhile,Ca^2 -activated CaM also in creased through the cell cycle(G1,S,G2M).Increasing observed in G1 meant that the entry of cells from G1 into S phase may require CaM accumulation,and,equally or even more important,Ca^2 -dependent activation of CaM.Ca^2 -activated CaM decreased after cell division.The results suggested that CaM gene expression and C^2 -modulated CaM activation act synergistically to accomplish the cell cycle progression.  相似文献   

3.
Jian LC  Li JH  Li PH  Chen TH 《Cell research》2000,10(2):103-114
Plasma membrane(PM) Ca^2 -ATPase activity in poplar apical bud meristematic cells during short-day(SD)-induced dormancy development was examined by a cerium precipitation EM-cytochemical method.Ca^2 -ATPase activity,indicated by the status of cerium phosphate precipitated grains,was localized mainly on the interior face(cytoplasmic side) of the PM when plants were grown under long days and reached a deep dormancy.A few reaction products were also observed on the nuclear envelope.When plant buds were developing dormancy after 28 to 42 d of SD exposure,almost no reaction products were present on the interior face of the PM.In contrast,a large number of cerium phosphate precipitated grains were distributed on the exterior face of the PM.After 70 d of SD exposure,when buds had developed a deep dormancy,the reaction products of Ca^2 -ATPase activity again appeared on the interior face of the PM.The results seemed suggesting that two kinds of Ca^2 -ATP ases may be present on the PM during the SD-induced dormancy in poplar.One is the Ca^2 -pumping ATPase,which is located on the interior face of the PM,for maintaining and restoring the Ca^2 homeostasis.The other might be and ecto-Ca^2 -ATPase,which is located on the exterior face of the PM,for the exocytosis of cell wall materials as suggested by the fact of the cell wall thickening during the dormancy development in poplar.  相似文献   

4.
Abdoon AS  Kandil OM  Zeng SM  Cui M 《Theriogenology》2011,76(7):1207-1214
Dromedary camel oocytes have the ability to spontaneous parthenogenetic activation and development in vivo and in vitro. The present study was conducted to investigate changes in mitochondrial distribution, adenosine triphosphate (ATP), and glutathione (GSH) contents and [Ca2+] oscillation during in vitro maturation and spontaneous parthenogentic activation of dromedary camel oocytes. Dromedary camel cumulus-oocyte complexes (COCs) were matured in TCM199 medium supplemented with 10% FCS + 10 μg/mL FSH + 10 IU hCG + 10 IU eCG + 10 ng/mL EGF and 50 μg/mL gentamycine. Maturation was performed at 38.5 °C under 5% CO2 in humidified air for 40 h. After maturation and removal of cumulus cells, oocytes were classified into: immature cultured (Group 1); metaphase II (M II, Group 2); and spontaneously parthenogenetically activated (with 2 polar bodies, Group 3); cleaved embryos (Group 4); and immature oocytes served as a control (Group 5). Cytoplasmic mitochondrial distribution, ATP-GSH contents, calcium [Ca2+] oscillation were determined. Results indicated that M II and spontaneously parthenogenetically activated oocytes represent 37.53% and 32.67% of the cultured oocytes, respectively, and 3.3% cleaved and developed to 2-16-cell stage embryos. Mitochondrial distribution, ATP-GSH contents and [Ca2+] oscillation were significantly (P < 0.01) differ between immature and matured dromedary camel oocytes. Mitochondrial distribution showed clustering form in matured oocytes without polar body. High polarized mitochondrial distribution (HPM) was detected in M II and spontaneously parthenogenetically activated oocytes, and the intensity of MitoTracker Red was higher in spontaneously parthenogenetically activated than M II. ATP-GSH contents and the duration of [Ca2+] oscillation were significantly (P < 0.01) higher in spontaneously parthenogenetically activated than M II oocytes or that matured without polar body. In conclusion, the higher incidence of spontaneously parthenogenetically activated in vitro matured dromedary camel oocytes could be attributed to the high polarized mitochondrial distribution associated with significantly higher ATP-GSH contents and duration of [Ca2+] oscillation.  相似文献   

5.
苹果果肉质膜微囊主动运输Ca2+的Ca2+-ATP酶特性   总被引:1,自引:0,他引:1  
应用45Ca2 + 示踪法研究了苹果果肉质膜微囊依赖于Ca2+ 的ATP 酶(Ca2+ATP酶)活性与Ca2+ 运输之间的关系及激素对该酶活性的影响。结果表明:Ca2 +ATP 酶存在于质膜上并受载体A23187 刺激而活性增加,该酶活性与依赖于ATP 的Ca2 + 运输依抑制剂EB、游离Ca2+ 和ATP浓度的变化并呈极为相似的饱和动力学特征;而其EB 半抑制浓度,Ca2+ 和ATP 半饱和浓度分别为0 .1 ,0 .1 和50 μmol/L,从而证实了正是Ca2+ATP酶推动苹果果肉质膜微囊的Ca2+ 的主动运输。生长素与萘乙酸均可促进苹果果肉质膜微囊Ca2+ATP酶活性和Ca2+ 吸收,而赤霉素则无此作用。  相似文献   

6.
Intracellular concentrations of potassium and phosphorus were determined by Electron Probe Microanalysis in mouse mature oocytes and zygotes. The oocytes were characterized by insignificant variations in the concentrations of these elements in the cytoplasm: 60 ± 4 and 103 ± 6 mM, respectively. In zygotes, on the contrary, significant variations were observed: 64 ± 16 and 84 ± 14 mM, respectively. Changes in the potassium homeostasis during the first cell cycle have been discussed.__________Translated from Ontogenez, Vol. 36, No. 2, 2005, pp. 123–127.Original Russian Text Copyright © 2005 by Pogorelov, Smolyaninova, Pogorelova, Goldstein.  相似文献   

7.
Red-light-induced swelling of the protoplasts isolated from hypocotyl of etiolated mung bean(Phaseolus radiatusL.)was observed only when Ca^2 ions were present in the medium.The optimal CaCl2 concentration was 250μM,Swlling response declined when Ca^2 was supplied into the medium after red light irradiation.The Ca^2 -chelator EGTA eliminated the red-light-induced swelling and 45Ca^2 accumulation in the protoplasts.In conltrast,A23187,a Ca^2 -ionophore,could mimic the effect of red light in darkness.These results indicate that Ca^2 may play a role in light signal transduction.In addition,swelling response was prevented by TFP and CPZ(both are CaM antagonists),implying the involvement of CaM in red-light-induced and Ca^2 -dependent protoplast swelling.  相似文献   

8.
Using steady-state fluorescence and nanosecond time-resolved fluorescence techniques, the Ca 2 -ATPase conformational changes induced by ganglioside GM3 were studied with different quenchers. The results showed that GM3 could significantly increase the lifetime of intrinsic fluorescence of Ca2 -ATPase reconstituted into proteoliposomes, and could also weaken the intrinsic fluorescence quenching by KI or hypocrellin B, HB. Further-more, by using quenching kinetic analysis of the time-resolved fluorescence, in the presence of GM3, the quenching constant (Ksv) and quenching efficiency were significantly lowered. The obtained results suggest that the oligosaccha-ride chain and the ceramide moieties of the GM3 molecule could interact with its counterparts of the Ca2 -ATPase re-spectively, thus change the conformation of the hydrophobic domain of the enzyme, making the tryptophan residues in different regions shift towards the hydrophilic-hydrophobic interface, and hence shorten the distance between the hy  相似文献   

9.
外源IAA 处理可以显著增加小麦胚芽鞘细胞NAD 激酶的催化活性,钙离子可以增强IAA 的作用效果,而钙离子通道抑制剂LaCl3 则起强烈的抑制作用,但在存在钙离子的条件下,这种抑制作用可以被钙离子载体A23187 消除;钙调蛋白能够在离体条件下激活经过DEAE 纤维素柱纯化的小麦胚芽鞘NAD激酶,经过IAA 处理的胚芽鞘细胞中能够刺激NAD 激酶活性的钙调蛋白含量明显增加,IAA 的这一作用受LaCl3 的抑制。上述结果表明Ca2+ /CaM 复合物介导了生长素对小麦胚芽鞘细胞NAD 激酶活性的促进作用。  相似文献   

10.
外加24表油菜素内酯(24epiBL) 无论在光下或暗中均可促进盐藻细胞分裂数的增加,激动素只在光下具有这种作用。外界Ca2+ 浓度升高时,24epiBL 促进细胞分裂的效果更为明显,而EGTA 可以抑制24epiBL引起的促进作用。Verapamil、W7 、环己酰亚胺均可抑制盐藻细胞分裂。Ca2 + 载体A23187 在低浓度(0 .25 μmol/L) 时具有促进分裂的作用。可以认为24epiBL对低等单细胞藻类具有生理作用,并且,其促进盐藻细胞分裂的机制与激动素是不同的,它不仅与Ca2 + 有关,而且与钙调素也有较密切的关系。  相似文献   

11.
  总被引:3,自引:0,他引:3  
Mouse oocyte aged in vitro cannot develop normally following activation. To investigate the roles of nucleus or cytoplasm elements in oocyte aged in vitro process and their subsequent development capability following activation, we reconstructed oocytes with MII chromosome spindle and cytoplasm from aged and fresh oocytes by nuclear transfer. The subsequent developmental potential after parthenogenetic activation (PA) or in vitro fertilization (IVF) was evaluated. After nuclear transfer, more than 75.6% of karyoplast and cytoplast pairs can be fused and reconstructed oocytes have a normal haploid karyotype. Following PA, aged oocytes cannot develop beyond four-cell stage, reconstructed oocytes from fresh nucleus and aged cytoplasm developed to blastocyst with a low percentage (9.1%). Instead, blastocyst formation rate of reconstructed oocyte from aged nucleus and fresh cytoplasm was higher (60.0%). Following IVF, zygote with diploid karyotype can be formed from zona pellucida (ZP)-free oocyte. After cultured in vitro, aged oocytes cannot develop beyond two-cell; reconstructed oocytes from fresh nucleus and aged cytoplasm developed to blastocyst with low percentage (15.0%). However, high blastocyst formation rate (86.2%) can be obtained from reconstructed oocytes from aged nucleus and fresh cytoplasm. Furthermore, after embryo transfer, three viable pups have been obtained, although the efficiency is very low. These observation demonstrated that cytoplasm is more crucial than nucleus to aging process. Fresh cytoplasm could partly rescue nucleus susceptibility to apoptosis from aging in vitro.  相似文献   

12.
大麦幼苗经短时间盐处理,尚未发生伤害时,虽然质膜上需Mg~(2+)和不需Mg~(2+)的两个Ca~(2+)转运系统的转运能力均基本未变,但两者的动力学特征却有所不同。在盐处理3h内,不需Mg~(2+)的Ca~(2+)转运过程对Ca~(2+)的亲和力便明显降低,而需Mg~(2+)的Ca~(2+)转运过程对Ca~(2+)的亲和力变化不大。较长时间盐处理,两个Ca~(2+)转运系统的转运能力和ATP亲和力均有不同程度的减小。这种减小与幼苗的伤害相伴出现,随处理时间加长而加剧。不同时间的盐处理下,质膜Ca~(2+)—ATP酶活性与不需Mg~(2+)的Ca~(2+)转运过程变化规律一致。Ca~(2+)—ATP酶受钙调素激活的特性在盐处理3h内即有所减小,至处理24h基本丧失。由动力学分析结果推测,短时间盐胁迫下质膜上两个Ca~(2+)转运系统的不同变化是植物的一种调节反应,它们在钙信使系统传递胁迫信号的过程中起不同作用。Ca~(2+)—ATP酶驱动的初级Ca~(2+)转运系统可能与胁迫信号的传递有关,而次级Ca~(2+)转运系统即可能起着信息传递之后将剩余 Ca~(2+)运出胞外的功能。较长时间盐胁迫下两系统Ca~(2+)转运能力的降低则是一种伤害反应。  相似文献   

13.
水分胁迫及复水过程中小麦幼苗叶片内Ca2+的定位   总被引:1,自引:0,他引:1  
展现了冬小麦幼苗在干旱胁迫及干旱后复水过程中叶肉细胞内Ca2 的动态分布 :在正常水分条件下生长的小麦幼苗 ,其细胞中的Ca2 主要位于液泡内 ,同时 ,细胞间隙中有大量的Ca2 分布。在水分胁迫下 ,随着胁迫时间的加长 ,液泡和细胞间隙的Ca2 逐渐进入细胞质 ,导致细胞质中自由Ca2 浓度过高 ,并对细胞造成伤害。复水后 ,细胞质中高浓度Ca2 迅速排入液泡和细胞间隙 ,细胞质中Ca2 浓度又基本恢复正常水平 ,形象地展示了细胞内Ca2 的稳态调控机制  相似文献   

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