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11.
Fusion of cultured dog kidney (MDCK) cells: I. Technique,fate of plasma membranes and of cell nuclei
Ulrich Kersting Heribert Joha Wieland Steigner Birgit Gassner Gerhard Gstraunthaler Walter Pfaller Hans Oberleithner 《The Journal of membrane biology》1989,111(1):37-48
Summary The evaluation of the intracellular signal train and its regulatory function in controlling transepithelial transport with electrophysiological methods often requires intracellular measurements with microelectrodes. However, multiple impalements in epithelial cells are hampered by the small size of the cells. In an attempt to avoid these problems we fused cells of an established cell line, Madin Darby canine kidney cells, originally derived from dog kidney, to giant cells by applying a modified polyethylene glycol method. During trypsin-induced detachment from the ground of the petri dish, individual cells grown in a monolayer incorporate volume and mainly lose basolateral plasma membrane by extrusion. By isovolumetric cell-to-cell fusion, spherical giant cells are formed within 2 hr. During this process a major part of the individual cell plasma membranes is internalized. Over three weeks following cell plasma membrane fusion degradation of single cell nuclei and cell nuclear fusion occurs. We conclude that this experimental approach opens the possibility to investigate ion transport of epithelia in culture by somatic cell genetic techniques. 相似文献
12.
José Cansado Elisa Longo Dolores Agrelo Tomás G. Villa 《FEMS microbiology letters》1989,65(1-2):233-237
Acridine orange, an intercalating dye usually employed in the curing of bacterial plasmids, was tested for its ability to cure K1 and K2 killer strains (laboratory and wine strains). The results showed a high curing percentage of the killer character. This was demonstrated by the loss of M1 or M2 dsRNAs (responsible for toxin production and resistance to it) and because the meiotic products exhibited non-Mendelian segregation. The curing percentages varied, depending on the strain but not on the killer type, and showed similar efficiency as compared with other known curing agents. 相似文献
13.
Anna-Maria M. Schmid 《Plant Systematics and Evolution》1989,164(1-4):239-252
The ultrastructure of the diatomSynedra cf.ulna was examined paying special attention to the Plattenband (platelet band). This structure was first described byGeitler in 1948 on the basis of LM observations and denotes a linear array of dictyosomes along the apical axis of the cell. The present investigation confirmsGeitler's observations in all essential details and demonstrates that the dictyosomes are arranged along polarized nuclear extensions running towards the cell poles. Laterally the extensions are accompanied by a number of microtubules. In large cells the total length of the nucleus thus may reach 400 µm and more. Since only the central part of the nucleus is DNA-positive with DAPI and acridine orange, the nuclear nature of the backbone of the Plattenband cannot be recognized by LM techniques. TEM investigation of serial apical and transapical sections, however, prove unambiguously the identity with extended parts of the nucleus.Dedicated to Prof. DrLothar Geitler on the occasion of his 90th birthday. 相似文献
14.
吖啶橙失活处理应用于不对称融合初步探讨 总被引:1,自引:0,他引:1
马铃薯栽培种和野生种叶肉原生质体经过吖啶橙(AO)处理后,暗培养两天,再光照4h而失活.失活程度取决于AO处理时间、AO浓度、光照时机等.四倍体失活浓度高于二倍体,处理后马上光照失活效果最强烈,8d后光照其小细胞团同未光照处理相差不大。AO失活的栽培种NO7同罗丹明6G(R6G)失活的Solanumbulbocastanum融合后可以发生代谢互补恢复分裂,已得到假定的杂种小愈伤组织. 相似文献
15.
Twelve cDNAs corresponding to mRNAs inducible by ethylene were isolated by differential screening of a cDNA library from ethylene-treated Citrus sinensis fruits. Northern analysis of RNA extracted from flavedo of ethylene-treated fruits and from fruits at different maturation stages showed that some of the mRNAs corresponding to these cDNAs were regulated both by ethylene treatment and during fruit maturation. The effect of exogenous ethylene on leaves and of endogenous ethylene on flowers showed that gene induction was not restricted to the flavedo tissue. The possible role of ethylene during maturation of the non-climacteric Citrus fruit is discussed. 相似文献
16.
Plants and fungi possess an outwardly directed plasma membrane proton pump that may regulate intracellular pH. We provide the first demonstration that amoebae of the slime mould Dictyostelium discoideum also possess a similar proton pump. It can be assayed either as an ATPase activity in highly purified plasma membranes or as a proton pump, after solubilization and reconstruction into liposomes. The pump is inhibited by vanadate, diethylstilbestrol (DES) and miconazole but not by azide or ouabain. The proton pump described here may represent the target for the action of DES and miconazole, both of which have previously been shown to induce stalk cell formation during the in vitro development of Dictyostelium. 相似文献
17.
Mauricio Goihman-Yahr Leo Pine Maria Cecilia Albornoz Luis Yarzabal Maria Helena De Gomez Blanca San Martin Ana Ocanto Tulio Molina Jacinto Convit 《Mycopathologia》1980,71(2):73-83
Mild sonication was used to obtain single cell suspensions of Paracoccidioides brasiliensis. These cells were intact by microscopic criteria. Direct cell counts in a given inoculum and colony formation on various media were used to determine plating efficiency. Sonicated and nonsonicated cell suspensions were used to study plating efficiency and to estimate viability by means of vital dyes. Methylene blue, Erythrosin B, and Janus green were unreliable when used with P. brasiliensis, but vital dyes were accurate when tested with Candida albicans.Acridine orange gave more meaningful results of viability. Estimates of viability, however, changed significantly as a result of relatively minor alterations in the composition of the suspending medium.In initial experiments, the plating efficiency of P. brasiliensis was dismally low. It descended abruptly with increasing dilution of inoculum. Efficiency was much improved if horse serum was added to brain heart infusion plates or if glucose glycine yeast extract (GGY) plates were incubated at room temperature and mycelial colonies were counted. With the technique we report, current plating efficiency of sonicated suspensions is of the order of 25 %. Our results and procedures have an important bearing upon those studies concerned with in vitro killing of P. brasiliensis in suspensions or with isolating this fungus from clinical or environmental specimens. 相似文献
18.
Wen-Zong Whong 《Mutation research》1979,60(3):301-312
The nature of the N2 effect for ICR-170, i.e., the greater mutagenic and lethal activities of this agent in the presence of N2 than O2, has been studied at the ad-3 region of Neurospora crassa. The characteristics of the N2 effect for ICR-170 were that (1) the N2 effect with ICR-170 was displayed in conidia when N2 was administered during, but not before or after, ICR-170 treatment, (2) the highly increased mutagenic and lethal activities of ICR-170 in the presence of N2 were due to an anoxic condition rather than to the presence of N2 per se, (3) the high killing activity of ICR-170 under N2 was due largely to increased cytoplasmic inactivation, (4) the N2 effect was a general phenomenon at the ad-3 region of N. crassa, and (5) the highly ICR-170-induced mutation in conidia under N2 was attributable to an actual enhancement in the mutagenic activity of ICR-170 rather than to selective killing. With regard to the mechanisms of the N2 effect with ICR-170, results indicate that this effect (1) was not due to more extracellular oxidative degradation of ICR-170 molecules in the presence of O2, or to a greater uptake of ICR-170 by conidia under N2, but (2) was due to the inhibition of conidial respiration under an anoxic environment. 相似文献
19.
Eliezer E. Goldschmidt 《Phytochemistry》1977,16(7):1046-1047
Chromoplasts from yellow orange (Citrus sinensis) fruit peel contain monogalactosyl diglycerides (MGDG), digalactosyl diglycerides (DGDG) and phosphatidyl glycerol (PG) in amounts similar to those found in chloroplasts from green fruit peel. Juice chromoplasts contain relatively little MGDG and no DGDG with high levels of phosphatidyl choline and phosphatidyl ethanolamine but no PG. 相似文献
20.