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磁场对蚕豆种子根生长和细胞分裂的影响 被引量:5
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作者 刘新成 李秋祯 +2 位作者 王轶 李幼静 何芸 《天津师大学报(自然科学版)》 2001年第1期61-63,共3页
研究不同磁场强度对蚕豆种子根的生长、细胞分裂和染色体形态的影响 .实验结果表明 ,磁场强度在 3 0 0 0~ 50 0 0 GS范围内 ,根的生长速率最快 ,根尖细胞分裂指数最高 ;磁场强度低于 3 0 0 0 GS时 ,对种子根的生长和细胞分裂指数影响... 研究不同磁场强度对蚕豆种子根的生长、细胞分裂和染色体形态的影响 .实验结果表明 ,磁场强度在 3 0 0 0~ 50 0 0 GS范围内 ,根的生长速率最快 ,根尖细胞分裂指数最高 ;磁场强度低于 3 0 0 0 GS时 ,对种子根的生长和细胞分裂指数影响不明显 ;高于 50 0 0 GS时 ,蚕豆根的生长速率和有丝分裂指数降低 .不同磁场强度对染色体畸变率没有明显的变化 . 展开更多
关键词 磁场 蚕豆 种子 有丝分裂 根生长 细胞分裂 染色体形态 生长速率
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稳态磁场对真核生物细胞骨架的影响 被引量:2
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作者 张磊 李志元 张欣 《科学通报》 EI CAS CSCD 北大核心 2019年第8期748-760,共13页
细胞骨架是一种重要的细胞器,主要包括微管、微丝和中间纤维,在维持细胞形态、调控胞内物质运输、调节细胞分裂和细胞迁移等方面起着重要的作用,参与生殖发育和肿瘤发生等多个生理和病理过程,是细胞生物学以及肿瘤生物学领域的重要研究... 细胞骨架是一种重要的细胞器,主要包括微管、微丝和中间纤维,在维持细胞形态、调控胞内物质运输、调节细胞分裂和细胞迁移等方面起着重要的作用,参与生殖发育和肿瘤发生等多个生理和病理过程,是细胞生物学以及肿瘤生物学领域的重要研究对象.从二十世纪七八十年代起,关于稳态磁场对真核生物细胞骨架影响的研究在理论解释和实验观测方面都取得了一系列进展.在理论解释方面,研究者不仅计算了肽键的微弱抗磁各向异性,而且进一步计算了微管多聚体较强的抗磁各向异性.在实验观测方面,研究者发现不仅体外纯化的微管或微丝能够沿着强磁场方向排列,并且细胞内由微管或微丝构成的相关结构也会受到稳态磁场的影响,例如纺锤体、精子和草履虫纤毛等.相比之下,磁场对中间纤维的影响研究较少.随着高场磁共振成像(magneticresonanceimaging,MRI)的研发与应用,以及稳态磁场在肿瘤治疗领域的潜在应用的逐步开发,进一步研究不同参数稳态磁场与体内细胞骨架之间的关系对研究和解释磁场对肿瘤发生和生殖发育等的影响至关重要. 展开更多
关键词 稳态磁场 细胞骨架 微管 微丝 抗磁各向异性 有丝分裂纺锤体 细胞分裂
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Cytological and transcriptional analysis reveal phosphatidylinositol signaling pathway plays key role in mitotic division of Pyropia yezoensis
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作者 Yunke ZHU Xinran WANG +2 位作者 Bin SUN Xianghai TANG Yunxiang MAO 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2022年第3期1148-1159,共12页
The phosphatidylinositol(PI)signaling system,a central regulator of eukaryotic metabolism,is widely found in eukaryotes for regulating a variety of cell activities.Most of the genes in the PI signaling system were fou... The phosphatidylinositol(PI)signaling system,a central regulator of eukaryotic metabolism,is widely found in eukaryotes for regulating a variety of cell activities.Most of the genes in the PI signaling system were found conserved in Pyropia yezoensis.In this experiment,wortmannin was used as an inhibitor to inhibit the activity of phosphatidylinositol-3 kinase(PI3K),an important regulator of the PI signaling system.After wortmannin treatment,the mitotic division of P.yezoensis was signifi cantly inhibited in a dose-dependent manner,and the mitotic division percentage was reduced by 68.1%and 91.9%in the 5-and 10-μmol/L groups,respectively.When thalli were treated with wortmannin,the levels of reactive oxygen species(ROS)were signifi cantly decreased.Furthermore,the expression level of PI3K was inhibited and the expression levels of downstream genes regulated by PI3K was signifi cantly changed.In the PI3K-AGC signaling pathway,the expression levels of Serine/threonine protein kinase(AGC)and cyclindependent kinases A(CDKA)were downregulated,while WEE1 kinase gene(WEE1)was upregulated.Three nicotinamide adenine dinucleotide phosphate(NADPH)oxidase genes were downregulated after wortmannin treatment.These results indicate that the PI signaling system plays an important role in the regulation of cell activity in P.yezoensis.It was speculated that the growth and development of P.yezoensis might be regulated by P.yezoensis PI3K,which promoted the expression of the AGC gene and further regulates the expression of downstream WEE1 and CDKA genes to advance mitotic division,and also promoted the expression level of NADPH oxidase that regulates ROS homeostasis. 展开更多
关键词 Pyropia yezoensis phosphatidylinositol signaling system reactive oxygen species mitotic division
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细胞周期抑制蛋白KRP1和转录因子GRF5回补拟南芥Hippo/sik1突变体的表型分析
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作者 王勤英 龚清秋 《南开大学学报(自然科学版)》 CAS CSCD 北大核心 2021年第3期48-53,59,共7页
器官大小调控在多细胞生物的个体发育中非常重要.模式植物拟南芥的叶片大小受到精密的调控:首先,叶原基通过有丝分裂实现细胞增殖,之后多数细胞迅速退出分裂,进入细胞延展阶段,达到最终的叶片大小.本课题组前期发现拟南芥丝/苏氨酸蛋白... 器官大小调控在多细胞生物的个体发育中非常重要.模式植物拟南芥的叶片大小受到精密的调控:首先,叶原基通过有丝分裂实现细胞增殖,之后多数细胞迅速退出分裂,进入细胞延展阶段,达到最终的叶片大小.本课题组前期发现拟南芥丝/苏氨酸蛋白激酶SIK1是限制动物器官大小的Hippo通路核心组分——蛋白激酶Hippo/MST的同功能蛋白.对第一对真叶发育过程进行观察,发现促进细胞增殖的GRF5转录因子与代表内复制启动的细胞周期抑制蛋白KRP1的转录水平均显著低于野生型.在此基础上,构建了KRP1和GRF5的过量表达载体,分别转化野生型与sik1突变体,筛选鉴定获得了T3纯合株系.表型分析显示,KRP1在野生型背景下过表达,加速了叶片延展;GRF5在野生型背景下过表达,叶片面积稍有增大,叶片呈深绿色.然而KRP1和GRF5在sik1中的过表达并未改变其叶片较小、植物发育迟缓的表型.研究结果表明sik1的器官变小表型并非由KRP1和GRF5功能缺失造成,SIK1真正的下游通路还有待探索. 展开更多
关键词 器官大小 有丝分裂退出 细胞分裂 拟南芥 Hippo通路
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Plk1在猪胎儿成纤维细胞有丝分裂进程中的亚细胞定位和功能研究
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作者 林德凤 董妍 +4 位作者 石凤垚 曹伟 苗懋东 芮荣 剧世强 《畜牧与兽医》 北大核心 2018年第7期51-56,共6页
本研究旨在探究Plk1在猪胎儿成纤维细胞中的亚细胞定位及其作用。通过间接免疫荧光技术检测了Plk1在猪胎儿成纤维细胞有丝分裂进程中的亚细胞定位,并通过Plk1特异性抑制剂GSK461364处理进一步分析Plk1在细胞有丝分裂进程中的潜在作用。... 本研究旨在探究Plk1在猪胎儿成纤维细胞中的亚细胞定位及其作用。通过间接免疫荧光技术检测了Plk1在猪胎儿成纤维细胞有丝分裂进程中的亚细胞定位,并通过Plk1特异性抑制剂GSK461364处理进一步分析Plk1在细胞有丝分裂进程中的潜在作用。结果显示:Plk1在猪胎儿成纤维细胞有丝分裂各个时期都有分布,且在细胞核周围有相对较高水平的Plk1表达;经GSK461364处理后,细胞活力显著降低,细胞周期进程阻滞在G2/M期,出现细胞核碎裂,并伴随着α-微管蛋白结构紊乱。研究表明:Plk1参与了调控猪胎儿成纤维细胞有丝分裂的进程,并与G2/M期的细胞核分裂和微管组装密切相关。 展开更多
关键词 猪胎儿成纤维细胞 PLK1 有丝分裂 细胞核 Α-微管蛋白
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Wound Healing Is a First Response in a Cancerous Pathway: Hyperplasia Developments to 4n Cell Cycling in Dysplasia Linked to Rb-Inactivation 被引量:5
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作者 Kirsten H. Walen 《Journal of Cancer Therapy》 2015年第10期906-916,共11页
In a series of publications, the hypothesis of a special-type of endo-polyploidy, marked by 4-chromatid chromosomes (diplochromosomes), in the initiation of tumorigenesis has been presented from in vitro experiments. ... In a series of publications, the hypothesis of a special-type of endo-polyploidy, marked by 4-chromatid chromosomes (diplochromosomes), in the initiation of tumorigenesis has been presented from in vitro experiments. This review uses cellular happenings in benign pre-neoplasia to substantiate this idea, which appears to be linked to the wound-healing process of injured tissue. Rarer association between a wound healing process and a cancer occurrence has long been known. The wound healing multi-program-system involved a phase of tetraploidy that showed diplochromosomes. The hypothesis is that the inflammatory phase may not always be sufficient in getting rid of dead and damaged cells (by apoptosis and autophagy), such that cells with genomic damage (DNA breakage) may survive by genomic repair associated with change to diplochromosomal tetraploidy. In vitro data have shown division of these cells to be an orderly, mechanistic two-step, meiotic-like system, resulting in only two types of progeny cells: 4n/4C/G1 and 2n/2C/G1 pseudo-diploid cells with hyperplastic-like growth-morphology. In vivo damage to tissues can be from many sources for example, physical, toxic environment or from a disease as in Barrett’s esophagus (BE) with acid reflux into the esophagus. For this condition, it is acknowledged that damage of the esophagus lining is a pre-condition to hyperplastic lesions of pre-neoplasia. These initial lesions were from “diploid” propagating cells and, 4n cells with G2 genomic content (no mitosis) accumulated in these lesions before a change to dysplasia. Cell cycle kinetics put these 4n cells in G1, which with S-phase entry would lead to asymmetric tetraploid mitoses, characteristic for dysplastic lesions. This change in hyperplasia to dysplasia is the root-essential condition for a potential progression of pre-neoplasia to cancer. In BE the hyperplastic lesion showed increasing gains of cells with inactivated p53 and p16[ink4a] genes, which destroyed the retinoblastoma (Rb) protein-control over S-phase 展开更多
关键词 mitotic SLIPPAGE Endotetraploidization Diplochromosomes Meiotic-Like division 4n/4C/G1 PROGENY PROLIFERATIVE Advantage INACTIVATED p53 p16[ink4a]
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Genomic Instability in Cancer I: DNA-Repair Triggering Primitive Hereditary 4n-Skewed, Amitotic Division-System, the Culprit in EMT/MET/Metaplasia Cancer-Concepts 被引量:3
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作者 Kirsten H. Walen 《Journal of Cancer Therapy》 2018年第12期974-997,共24页
The objective was to gain proof of genome damage-repair induced mitotic slippage process (MSP) to 4n-diplochromosome skewed division-system, earlier suggested to have “cancer-deciding” consequences. Our damage-model... The objective was to gain proof of genome damage-repair induced mitotic slippage process (MSP) to 4n-diplochromosome skewed division-system, earlier suggested to have “cancer-deciding” consequences. Our damage-model showed two succeeding phases: molecular mutations for initiation of fitness-gained cells, and large chromosomal changes to aneuploidy from inherited DNA-breakage-repair inaccuracies. The mutations were gained while DNA-repair and DNA-replication, co-existed in the route to tetraploidy, a phenomenon also expressed for some existing unicellular organisms. These organisms also showed genome reductive, amitotic, meioticlike division, and was the origin of human genome conserved, self-inflicted 90° reorientation of the 4n nucleus relative to the cytoskeleton axis. In the in vitro DNA-damage model, this remarkable 4n-event deciding “flat-upright” cell-growth characteristics showed several consequences, for example, cancer-important, E-cadherin-β-catenin cell-to-cell adherence destruction, which gave diploid progeny cells, mobility freedom from cell contact inhibition, likely in renewal tissues. This 4n-skewed division-system with inheritance in progeny cells for repeat occurrences as mentioned for flat-up-right growth patterns is similar to claimed concepts of metaplasia-EMT/MET embryogenesis events in cancer evolution. A scrutiny of this literature, proof-wise invalidated this embryological concept by tetraploid 8C cells occurring in MET events and, was noted for small cell occurrence, i.e., diploidy from 4n-8C reductive division, an also event for tumor relapse cells, derived from genome damaging therapy agents. Pre-cancer hyperplasia reported MSP, cadherincatenin destruction and 90° perpendicularity to basal cell membrane. The DNA-damage-repair model can weed-out therapy-agents triggering 4n-skewed division. Cancer-control, beginning-information, is likely from mutational identity of the 4n derived fitness-gained cells. 展开更多
关键词 CANCER Evolution DNA-Damage-Repair mitotic Slippage HEREDITARY PRIMITIVE Tetraploidy 90° Amitotic Skewed division Fitness-Gain Embryogenesis-Type EMT/MET Human Cell Conservation
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