共查询到20条相似文献，搜索用时 968 毫秒
1.
[目的]构建并优化滩涂适生金银花的组培体系。[方法]以具有活力的金银花茎段、叶芽和叶片为材料,采用混合水平的正交试验设计,以MS为基本培养基,与不同浓度比例的NAA、IBA、6-BA、KT等植物生长调节剂构成金银花诱导愈伤组织、丛芽分化、生根的组合方案,对金银花组织培养快繁技术开展系统研究。[结果]外植体类型影响愈伤组织的产生,叶芽的愈伤组织诱导分化率显著高于茎段和叶片(P0.05),诱导出的愈伤组织结构紧密。不同植物生长调节剂组合的培养基对愈伤组织的诱导率也有显著影响(P0.05)。愈伤组织在培养基MS+0.05 mg/L 6-BA+1.0 mg/L NAA中生长良好,具备较高的分化能力。含有低浓度的生长素和分裂素的培养基MS+0.1 mg/L 6-BA+0.05 mg/L NAA更有利于金银花愈伤组织诱导丛芽分化,能够从数量和质量上改善分化出的丛芽素质。在诱导根分化的培养基MS+0.03 mg/L NAA+1.00 mg/L IBA中,根的分化效率明显提高,丛根更为密集,有利于扩大繁殖系数。[结论]试验为金银花提供了从"外植体选择→诱导愈伤组织→丛芽分化→生根"等整个过程中优化的组培快繁体系,为耐盐金银花滩涂规模化种植提供了技术支撑。 相似文献
2.
The granulocyte-macrophage colony-stimulating factors 总被引：77，自引：0，他引：77
D Metcalf 《Science (New York, N.Y.)》1985,229(4708):16-22
The granulocyte-macrophage colony-stimulating factors are well-characterized specific glycoproteins that interact to control the production, differentiation, and function of two related white cell populations of the blood, the granulocytes and monocyte-macrophages. Widely produced in the body, these regulators probably play an important role in resistance to infections. The proliferation of myeloid leukemia cells remains dependent on stimulation by colony-stimulating factors, although one of them also has the ability to suppress leukemic populations by inducing terminal differentiation. 相似文献
3.
Most mammalian somatic cells are thought to have a limited proliferative capacity because they permanently stop dividing after a finite number of divisions in culture, a state termed replicative cell senescence. Here we show that most oligodendrocyte precursor cells purified from postnatal rat optic nerve can proliferate indefinitely in serum-free culture if prevented from differentiating; various cell cycle-inhibitory proteins increase, but the cells do not stop dividing. The cells maintain high telomerase activity and p53- and Rb-dependent cell cycle checkpoint responses, and serum or genotoxic drugs induce them to acquire a senescence-like phenotype. Our findings suggest that some normal rodent precursor cells have an unlimited proliferative capacity if cultured in conditions that avoid both differentiation and the activation of checkpoint responses that arrest the cell cycle. 相似文献
4.
Mullen AC High FA Hutchins AS Lee HW Villarino AV Livingston DM Kung AL Cereb N Yao TP Yang SY Reiner SL 《Science (New York, N.Y.)》2001,292(5523):1907-1910
How cytokines control differentiation of helper T (TH) cells is controversial. We show that T-bet, without apparent assistance from interleukin 12 (IL-12)/STAT4, specifies TH1 effector fate by targeting chromatin remodeling to individual interferon-gamma (IFN-gamma) alleles and by inducing IL-12 receptor beta2 expression. Subsequently, it appears that IL-12/STAT4 serves two essential functions in the development of TH1 cells: as growth signal, inducing survival and cell division; and as trans-activator, prolonging IFN-gamma synthesis through a genetic interaction with the coactivator, CREB-binding protein. These results suggest that a cytokine does not simply induce TH fate choice but instead may act as an essential secondary stimulus that mediates selective survival of a lineage. 相似文献
5.
诱导多能干细胞（induced pluripotent stem cells, iPS）是借助基因导入技术将某些转录因子导入人或动物的体细胞,使体细胞重编程而得到的多能性细胞。iPS细胞来源丰富,研究表明利用不同的载体诱导系统或不同的转录因子组合,多种体细胞都可被重编程为iPS细胞,如成纤维细胞、肝细胞、角质细胞及脐带血细胞等。作为干细胞中新的一员,iPS细胞在克隆形态、基因表达模式、表面标志物、拟胚体形成、畸胎瘤及嵌合体形成（小鼠）、分化能力等方面与胚胎干细胞（embryonic stem cell, ESC）非常相似。与胚胎干细胞一样,在特定的诱导条件下,iPS细胞在体外可被诱导分化为多种细胞,如心肌细胞、血细胞、生殖细胞等,进一步拉近了干细胞和临床疾病治疗的距离,iPS细胞也成为细胞治疗及组织器官再生最有前景的种子细胞,在细胞替代性治疗、发病机理研究及新药筛选方面具有潜在价值。雄性不育不仅影响人类正常健康生活,对畜牧业的发展也极为不利。国内外的研究成果表明,给予适当的诱导物及诱导条件,人和小鼠的iPS细胞体外可被诱导分化为原始生殖细胞（primordial germ cells, PGCs）、精子细胞及其前体细胞。这些研究不仅避免了胚胎干细胞研究领域存在的取材困难、免疫排斥和伦理道德等问题,还为揭示雄性生殖细胞的发育机制及研究雄性不育提供了较好的研究平台。由人iPS细胞诱导得到的雄性配子可为患者提供自身的雄性配子产生后代,避免了免疫排斥问题,为未来治疗雄性不育带来曙光。iPS细胞体外诱导分化技术对现代畜牧业发展也具有巨大的潜在应用价值,可进行转基因动物的生产。现从不同的诱导剂、不同的培养条件及iPS细胞体外诱导分化优势等方面,对iPS细胞体外定向诱导分化为雄性生殖细胞的研究进展及应用前景进行综述和展望。 相似文献
6.
月季组培快繁技术的研究 总被引：12，自引：0，他引：12
通过诱导芽分化和诱导愈伤两种途径 ,研究不同植物生长调节剂及浓度、对外植体萌发和生根的影响。MS附加不同种类、不同浓度的细胞分裂素和生长素 ,进行正交设计。结果表明 ,细胞分裂素 6 - BA分别与 3种生长素NAA,IAA,IBA配合使用均能诱导月季出芽。 相似文献
7.
以landersberg生态型的拟南芥为试材,建立了一套简便有效的组培体系。无菌苗的生长采用竖直培养,易于收集外植体。莲座叶、叶柄、下胚轴、根分别作为外植体在B5+5 mg/L2,4-D+0.5 mg/L KT培养基上诱导愈伤组织,结果表明,莲座叶作外植体出愈慢,出愈率低,愈伤组织质量较差;叶柄、下胚轴和根作外植体出愈快,且愈伤组织质量好,后期易分化。根外植体在MS+5 mg/L KT+0.1 mg/L IAA配方的出芽诱导培养基上诱导2～3周后,愈伤组织能有效分化出芽,分化率达100％。分化出的芽移至MS+2 mg/L NAA培养基上竖直培养,2周左右诱导分化出根,然后移至MS培养基上开花结果。 相似文献
8.
猪骨骼肌卫星细胞分离培养、鉴定及其生物学特性 总被引：2，自引：0，他引：2
【目的】建立猪骨骼肌卫星细胞体外分离、纯化及鉴定的方法,并对其生物学特性进行探讨,为进一步研究猪肌肉生长发育提供良好的细胞模型。【方法】选取1日龄仔猪背最长肌为材料,无菌状态下将背最长肌剪碎为肉糜状。此后采用浓度为0.2%的Ⅰ型胶原酶消化90 min,再加入浓度为0.25%的胰蛋白酶37 ℃联合消化30 min。经终止消化、过滤、重悬后将分离得到的细胞置于37 ℃、5% CO2细胞培养箱中培养。选用反复差速贴壁法对骨骼肌卫星细胞进行纯化,第一次纯化选择在细胞接种2 h后,将未贴壁细胞转移至新培养皿。上清液继续培养18 h后,对卫星细胞进行第二次差速贴壁纯化。当细胞密度达70%—80%时可对细胞进行传代或冻存处理。利用细胞免疫荧光技术检测P2代卫星细胞标志基因Pax7、MyoD的蛋白表达情况,并绘制卫星细胞生长曲线。分别添加不同诱导分化液使卫星细胞定向分化为肌细胞、脂肪细胞、成骨细胞,检测成肌分化标志基因MHC的免疫荧光,鉴定卫星细胞肌管形成情况;油红O染色及油红O定量鉴定卫星细胞诱导成脂分化效果;茜素红染色鉴定卫星细胞成骨分化能力,qRT-PCR检测成肌、成脂、成骨进程中关键基因的表达。【结果】通过两步酶消化和反复差速贴壁法分离纯化得到了纯度较高的卫星细胞,刚分离的细胞折光性强,贴壁后呈梭形或纺锤形,此后细胞延展并开始快速增殖。卫星细胞特异标志蛋白Pax7、MyoD细胞免疫荧光鉴定结果呈阳性,表明分离细胞为骨骼肌卫星细胞。骨骼肌卫星细胞增殖过程经潜伏期、生长期最终达到平台期,细胞生长曲线呈“S”型。当细胞生长至90%密度时,卫星细胞会出现自融合现象。对分离的骨骼肌卫星细胞成肌诱导分化后,可见邻近卫星细胞融合形成大量粗长肌管,多核肌管呈方向性排列,成肌标志蛋白MHC染色呈阳性。qRT-PCR结果显示标志基因MyoD、MyoG在成肌诱导分化过程中二者均呈先上升后下降趋势。经成脂诱导后细胞形态变为三角形,连续诱导发现脂滴出现并聚集成大脂滴,油红O染色可见大量红色葡萄样脂滴。油红O定量检测结果表明,成脂诱导过程中甘油三酯含量呈稳步上升趋势,各时间点均存在极显著差异（P<0.01）。qRT-PCR结果显示,PPARγ基因表达量在诱导中后期高表达;FABP4在诱导分化第6天达到最高,极显著高于其余时间点（P<0.01）;CEBP/β和HSL表达趋势一致,均呈先升高后降低趋势。诱导成骨分化后,发现细胞形态变为不规则状,诱导后期细胞复层生长形成骨钙结节,茜素红染色可见圆形不透明钙化结节,数量和密度较未诱导时期都明显增加,结果表明细胞出现成骨向分化。成骨标志基因BGLAP、RUNX2的表达量也随诱导进程呈稳步上升趋势,相比未诱导细胞差异极显著（P<0.01）。【结论】建立了基于联合酶消化和反复差速贴壁实现猪骨骼肌卫星细胞分离和纯化的方法,所得细胞增殖能力强且具有多向分化潜能,为猪骨骼肌卫星细胞作为种子细胞用于未来组织工程研究提供了技术平台。 相似文献
9.
以新铁炮百合的鳞片为试材,研究不同接种方式、不同培养基配方对小鳞茎诱导率、芽苗分化率、增殖率以及生根率的影响。结果表明,诱导小鳞茎适宜的培养基为MS＋NAA1.0＋6-BA2.0;鳞片垂直、内表面向下和向上三种接种方式中,均以内表面向上接种的小鳞茎诱导率为最高,达到206.7%;芽苗增殖效果最佳的培养基为MS＋6-BA1.0,增殖率达223.3%;较易生根的培养基为MS＋NAA0.5＋IBA0.5,生根率达78.3%。 相似文献
10.
Leukemic cells cultured in the presence of various conditioned media differentiate into macrophages. This finding suggested that the maintenance of undifferentiated state and self-renewal in vivo may be related to the inability of the host to generate an appropriate level of differentiation factor (DF). Evidence for this hypothesis was derived from experiments in vitro and in vivo with myeloid leukemia of rat. The following results were obtained: (i) in vitro, the percentage of cell differentiation at a fixed concentration of DF was inversely related to the concentration of cells; (ii) leukemic cell inoculates that were lethal to 7-day-old rats were rejected by 21-day-old rats; (iii) leukemic cells in diffusion chambers underwent differentiation in 21-day-old rats but not in 7-day-old rats; (iv) organs from 21-day-old rats contained more DF activity than those of 7-day-old rats; (v) treatment of rats with DF in diffusion chambers resulted in leukemic cell differentiation inside the chamber; and (vi) the development of leukemia in 7-day-old rats was aborted by treatment with DF. These results show that the differentiation of rat leukemia cells requires the appropriate level of DF. The proliferation of transplanted leukemia cells in 7-day-old rats goes unchecked because of inadequate generation of DF. Conversely, in the 21-day-old rats, rejection is accomplished by differentiation of the transplanted cells. 相似文献
11.
滇杨不同外植体分化培养研究 总被引：1，自引：0，他引：1
以MS为基本培养基,采取滇杨萌生出的不同外植体,附加不同浓度的激素筛选诱导分化培养方案。结果表明: 滇杨叶片不定芽诱导的较优培养基为MS+6-BA 1.0mg/L+NAA 0.05mg/L;滇杨叶柄和嫩茎不定芽诱导的较优培养基均为：MS+6-BA 0.5mg/L+NAA 0.05mg/L;叶片、叶柄以及嫩茎其芽的诱导分化率分别是40%,80%,20%。试验结果可为滇杨遗传改良、种质资源保存及快速繁殖提供理论及实践指导。 相似文献
12.
Purified human granulocyte-macrophage colony-stimulating factor: direct action on neutrophils 总被引：57，自引：0，他引：57
J C Gasson R H Weisbart S E Kaufman S C Clark R M Hewick G G Wong D W Golde 《Science (New York, N.Y.)》1984,226(4680):1339-1342
Neutrophil migration inhibition factor from T lymphocytes (NIF-T) is a lymphokine that acts to localize granulocytes. Medium conditioned by the Mo human T-lymphoblast cell line was used to purify NIF-T, a glycoprotein with a molecular weight of 22,000. The NIF-T was found to potently stimulate the growth of granulocyte and macrophage colonies from human bone marrow and colony formation by the KG-1 myeloid leukemia cell line. Thus a human lymphokine (NIF-T) that modulates the activities of mature neutrophilic granulocytes is also a colony-stimulating factor acting on precursors to induce growth and differentiation of new effector cells. 相似文献
13.
Appearance of a new nucleosomal protein during differentiation of human leukemia (HL-60) cells 总被引：1，自引：0，他引：1
A 60-kilodalton protein was identified in chromatin digested by micrococcal nuclease during retinoic acid-induced differentiation of human leukemia (HL-60) cells to mature-like granulocytes. The protein was not detected in a retinoic acid-resistant variant of the HL-60 cell line treated with retinoic acid, in HL-60 cells induced with dimethyl sulfoxide, or in normal human granulocytes. This protein may have an important role in the regulation of retinoic acid-induced leukemic cell differentiation. 相似文献
14.
Thymic requirement for clonal deletion during T cell development 总被引：14，自引：0，他引：14
During T cell differentiation, self tolerance is established in part by the deletion of self-reactive T cells within the thymus (negative selection). The presence of T cell receptor (TCR)-alpha beta + T cells in older athymic (nu/nu) mice indicates that some T cells can also mature without thymic influence. Therefore, to determine whether the thymus is required for negative selection, TCR V beta expression was compared in athymic nu/nu mice and their congenic normal littermates. T cells expressing V beta 3 proteins are specific for minor lymphocyte stimulatory (Mlsc) determinants and are deleted intrathymically due to self tolerance in Mlsc+ mouse strains. Here it is shown that V beta 3+ T cells are deleted in Mlsc+ BALB/c nu/+ mice, but not in their BALB/c nu/nu littermates. Thus, the thymus is required for clonal deletion during T cell development. 相似文献
15.
Monoclonal antibody-mediated tumor regression by induction of apoptosis 总被引：166，自引：0，他引：166
B C Trauth C Klas A M Peters S Matzku P M?ller W Falk K M Debatin P H Krammer 《Science (New York, N.Y.)》1989,245(4915):301-305
To characterize cell surface molecules involved in control of growth of malignant lymphocytes, monoclonal antibodies were raised against the human B lymphoblast cell line SKW6.4. One monoclonal antibody, anti-APO-1, reacted with a 52-kilodalton antigen (APO-1) on a set of activated human lymphocytes, on malignant human lymphocyte lines, and on some patient-derived leukemic cells. Nanogram quantities of anti-APO-1 completely blocked proliferation of cells bearing APO-1 in vitro in a manner characteristic of a process called programmed cell death or apoptosis. Cell death was preceded by changes in cell morphology and fragmentation of DNA. This process was distinct from antibody- and complement-dependent cell lysis and was mediated by the antibody alone. A single intravenous injection of anti-APO-1 into nu/nu mice carrying a xenotransplant of a human B cell tumor induced regression of this tumor within a few days. Histological thin sections of the regressing tumor showed that anti-APO-1 was able to induce apoptosis in vivo. Thus, induction of apoptosis as a consequence of a signal mediated through cell surface molecules like APO-1 may be a useful therapeutic approach in treatment of malignancy. 相似文献
16.
为了建立金柑(Fortunella japonica (Thunb.) Swingle)组织培养与快速繁殖体系,本研究以金柑胚根、子叶、茎段、叶片等不同外植体为材料,采用器官发生型以及短枝扦插型为主要培养途径,进行金柑的组织培养,研究不同浓度的植物生长调节剂对金柑快速繁殖体系建立的影响以及愈伤组织诱导和分化的最适条件,筛选出诱导愈伤组织形成不定芽的最佳外植体与最适培养基。研究结果表明,金柑诱导愈伤组织形成不定芽的最佳外植体为幼嫩的茎段,诱导金柑子叶形成愈伤组织的最佳培养基为MS+1.5 mg/L 6-BA +1.0 mg/L NAA+3% 蔗糖+0.7% 琼脂,诱导子叶愈伤组织分化不定芽的最佳培养基为MS+1.0 mg/L 6-BA+0.1 mg/L IBA+3% 蔗糖+0.7% 琼脂。由此证明上述组织培养途径是可行的。 相似文献
17.
蔗糖与麦芽糖质量浓度及添加成分对水稻成熟胚培养的效应 总被引：1，自引：0，他引：1
魏日凤 《福建农林大学学报(自然科学版)》2006,35(6):565-568
以IR54、639、金糯2号、特优63等4个水稻品种的成熟胚为外植体,以MS为基本培养基,研究了蔗糖与麦芽糖质量浓度及不同添加成分对水稻成熟胚培养的影响.结果表明,在这2种糖质量浓度及其配比试验中,在麦芽糖与蔗糖总量为60 g.L-1下,麦芽糖与蔗糖质量浓度比为1∶2时,愈伤组织诱导率、愈伤组织分化率、绿苗分化率均最高;0.5 mg.L-12,4-D和2 mg.L-1KT配合使用,比使用其他激素配比效果好;不同水稻基因型在不同培养基中的诱导效应存在差异. 相似文献
18.
不同培养基及激素配比对小麦成熟胚离体培养的影响 总被引：1，自引：0，他引：1
[目的]建立适于优良小麦品种遗传转化的高效组织培养再生体系。[方法]以小麦品种豫麦18和豫麦70成熟胚为外植体,探讨了2种培养基和4种激素配比对小麦成熟胚离体培养的影响。[结果]L3培养基的平均愈伤组织诱导率和分化率都明显高于MS培养基,供试2个品种平均出愈率达91.0%以上,平均分化率达46.4%。不同激素及其配比均可诱导小麦成熟胚愈伤组织分化,但不同处理分化率差别很大(10.5%~50.0%);以L3为分化培养基,同时添加2,4-D 0.1mg/L,6-BA 1.5 mg/L的激素配比更有利于愈伤组织的分化,平均分化率达到50.0%。[结论]MS、L3两种基本培养基对小麦成熟胚愈伤组织诱导率均比较高,且差别不大。不同激素配比对小麦成熟胚愈伤组织分化率影响很大。 相似文献
19.
20.
大穗黑麦草成熟种子愈伤组织诱导及分化的研究 总被引：2，自引：0，他引：2
以大穗黑麦草成熟种子为外植体 ,采用MS基本培养基 ,研究了不同浓度的 2 ,4-D和 6-BA及其组合对其愈伤组织诱导的影响 ,不同浓度的NAA和 6-BA组合对愈伤组织分化成苗的影响。结果表明 :不同浓度 2 ,4-D对大穗黑麦草愈伤组织诱导率差异显著 ,以 7mg/L效果最好 ,浓度过高 ,愈伤组织诱导率下降 ;在 0～ 1 .0mg/L范围内 ,6-BA浓度越高 ,愈伤组织诱导率越高 ,但长势渐差 ;2 ,4-D + 6-BA的不同配比浓度的愈伤组织诱导率存在差异 ,以MS + 7mg/L 2 ,4-D + 0mg/L 6-BA的组合为最优 ,产生的愈伤组织数量多、质量好 ;NAA+ 6-BA不同配比浓度的愈伤组织分化率存在一定差异 ,以MS +NAA 0 .5mg/L + 6-BA 1mg/L的愈伤组织分化率最高。初步建立了一个以大穗黑麦草成熟种子为外植体的愈伤组织诱导及分化体系 相似文献