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fgf20 is essential for initiating zebrafish fin regeneration 总被引：1，自引：0，他引：1
Epimorphic regeneration requires the presence or creation of pluripotent cells capable of reproducing lost organs. Zebrafish fin regeneration is mediated by the creation of blastema cells. Here, we characterize the devoid of blastema (dob) mutant that fails fin regeneration during initial steps, forms abnormal regeneration epithelium, and does not form blastema. This mutation has no impact on embryonic survival. Dob results from an fgf20a null mutation, Y148S. Fgf20a is expressed during initiation of fin regeneration at the epithelial-mesenchymal boundary and later overlaps with the blastema marker msxb. Thus, fgf20a has a regeneration-specific requirement, initiating fin regeneration, and controlling blastema formation. 相似文献
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Molecular basis for the nerve dependence of limb regeneration in an adult vertebrate 总被引：1，自引：0，他引：1
Kumar A Godwin JW Gates PB Garza-Garcia AA Brockes JP 《Science (New York, N.Y.)》2007,318(5851):772-777
The limb blastemal cells of an adult salamander regenerate the structures distal to the level of amputation, and the surface protein Prod 1 is a critical determinant of their proximodistal identity. The anterior gradient protein family member nAG is a secreted ligand for Prod 1 and a growth factor for cultured newt blastemal cells. nAG is sequentially expressed after amputation in the regenerating nerve and the wound epidermis-the key tissues of the stem cell niche-and its expression in both locations is abrogated by denervation. The local expression of nAG after electroporation is sufficient to rescue a denervated blastema and regenerate the distal structures. Our analysis brings together the positional identity of the blastema and the classical nerve dependence of limb regeneration. 相似文献
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Material staining with aldehyde fuchsin appeared in sensory ganglion cells supplying a regenerating limb or nerve-induced blastema and in regenerating nerve fibers within the blastema. With the electron microscope, large (1000 to 2500 angstroms), dense granules were observed in the perikarya and within end bulbs of peripheral nerves. Secretory materials may be elaborated and transported by neurons during limb regeneration and induction in the newt. 相似文献
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目的：黔西南薏苡种质资源主要是地方品种,不同品种各性状差异较大,尤其是越年再生性差异较大,旨在鉴定各薏苡种质之间的再生能力的差异。方法：通过收集筛选薏苡种质资源10份,田间自然种植,对不同品种的再生能力进行鉴定。结果：结果表明,10份种质越年再生能力差异极大,黑壳薏苡2越年再生能力最强,产量低;白壳薏苡越年再生能力较差,但产量高;且越年再生季和头季之间性状差异较大;结论：综合各种质优缺点,当地应以白壳小薏苡作为良种种植,黑壳薏苡可用作选育其多年生薏苡种质。 相似文献
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A hallmark of aging is diminished regenerative potential of tissues, but the mechanism of this decline is unknown. Analysis of injured muscle revealed that, with age, resident precursor cells (satellite cells) had a markedly impaired propensity to proliferate and to produce myoblasts necessary for muscle regeneration. This was due to insufficient up-regulation of the Notch ligand Delta and, thus, diminished activation of Notch in aged, regenerating muscle. Inhibition of Notch impaired regeneration of young muscle, whereas forced activation of Notch restored regenerative potential to old muscle. Thus, Notch signaling is a key determinant of muscle regenerative potential that declines with age. 相似文献
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‘Damas1869’李离体叶片不定芽再生影响因素分析 总被引：2，自引：0，他引：2
以‘Damas1869’李试管苗幼嫩叶片为试材,对影响离体叶片再生的培养基种类、激素浓度、叶片放置方式、暗培养时间、琼脂用量等关键因素进行研究。结果表明:F14培养基再生效果最好,明显优于MS和WPM培养基;最佳激素配比为4.0 mg/L TDZ+0.5 mg/L IBA,用4.5 g/L琼脂配制偏软的再生培养基,叶片近轴面向下接触培养基,暗培养5 d后转光下培养有利于提高离体叶片的再生效率,再生率可保持在73.5%左右,平均每叶再生3~5个芽。 相似文献
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研究了青霉素、甘氨酸、溶菌酶浓度、酶解温度、菌龄、再生培养基对生防芽孢杆菌Snb2原生质体的形成与再生的影响。培养液中青霉素和甘氨酸的终含量分别为0.3%和1.0%时,菌株Snb2的生长量最佳;菌株原生质体形成的最佳条件是,溶菌酶浓度为2.0mg·mL-1,酶解温度为35℃,生产原生质体的最佳菌龄为对数生长中期;在最佳再生培养基HCNB培养基上,原生质体再生率为66.0%。 相似文献
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Montarras D Morgan J Collins C Relaix F Zaffran S Cumano A Partridge T Buckingham M 《Science (New York, N.Y.)》2005,309(5743):2064-2067
Muscle satellite cells contribute to muscle regeneration. We have used a Pax3(GFP/+) mouse line to directly isolate (Pax3)(green fluorescent protein)-expressing muscle satellite cells, by flow cytometry from adult skeletal muscles, as a homogeneous population of small, nongranular, Pax7+, CD34+, CD45-, Sca1- cells. The flow cytometry parameters thus established enabled us to isolate satellite cells from wild-type muscles. Such cells, grafted into muscles of mdx nu/nu mice, contributed both to fiber repair and to the muscle satellite cell compartment. Expansion of these cells in culture before engraftment reduced their regenerative capacity. 相似文献
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Dudakov JA Hanash AM Jenq RR Young LF Ghosh A Singer NV West ML Smith OM Holland AM Tsai JJ Boyd RL van den Brink MR 《Science (New York, N.Y.)》2012,336(6077):91-95
Endogenous thymic regeneration is a crucial function that allows for renewal of immune competence after stress, infection, or immunodepletion. However, the mechanisms governing this regeneration remain poorly understood. We detail such a mechanism, centered on interleukin-22 (IL-22) and triggered by the depletion of CD4(+)CD8(+) double-positive thymocytes. Intrathymic levels of IL-22 were increased after thymic insult, and thymic recovery was impaired in IL-22-deficient mice. IL-22, which signaled through thymic epithelial cells and promoted their proliferation and survival, was up-regulated by radio-resistant RORγ(t)(+)CCR6(+)NKp46(-) lymphoid tissue inducer cells after thymic injury in an IL-23-dependent manner. Administration of IL-22 enhanced thymic recovery after total body irradiation. These studies reveal mechanisms of endogenous thymic repair and offer innovative regenerative strategies for improving immune competence. 相似文献
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Pluripotent cells in the embryo can generate all cell types, but lineage-restricted cells are generally thought to replenish adult tissues. Planarians are flatworms and regenerate from tiny body fragments, a process requiring a population of proliferating cells (neoblasts). Whether regeneration is accomplished by pluripotent cells or by the collective activity of multiple lineage-restricted cell types is unknown. We used ionizing radiation and single-cell transplantation to identify neoblasts that can form large descendant-cell colonies in vivo. These clonogenic neoblasts (cNeoblasts) produce cells that differentiate into neuronal, intestinal, and other known postmitotic cell types and are distributed throughout the body. Single transplanted cNeoblasts restored regeneration in lethally irradiated hosts. We conclude that broadly distributed, adult pluripotent stem cells underlie the remarkable regenerative abilities of planarians. 相似文献
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[目的]研究农杆菌介导的甘蓝型油菜下胚轴遗传再生体系。[方法]以甘蓝型油菜为试验材料,以组织培养为基础。以下胚轴为外植体,以统计出愈率和出苗率为指标,探讨农杆菌介导的遗传再生苗形成的影响因素。以G蛋白信号转导调节蛋白（RGS）为例,建立稳定的甘蓝型油菜下胚轴遗传再生体系。[结果]种子经10％NaCl0灭菌20mim后播种,基底用1／2MS配琼脂,直径6cm的培养罐50粒,光照充足（200μmol／m^2·s）,成功获得RGSi干扰表达阳性株系。[结论]试验以下胚轴为外植体,系统研究了甘蓝型油菜组织培养过程中各种因素对再生苗形成的影响,建立了有效的下胚轴遗传再生体系。 相似文献
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以'尖叶芥蓝'、'中花粗心芥蓝'和'迟花芥蓝'3个品种为材料,研究苯基噻二唑脲(TDZ)预处理、不同激素配比、基因型和外植体类型对不定芽再生的影响,建立芥蓝离体高频再生体系.结果表明:3个品种中,'中花粗心芥蓝'再生能力最强;不同外植体类型中再生率由大到小依次为:下胚轴、带柄子叶、子叶块;不定芽再生的最佳激素组合为0.2 mg·L-1NAA+6 mg·L-16-BA;以此激素组合为基础,下胚轴经0.5 mg·L-1TDZ浸泡30 min预处理接种在分化培养基(MS+0.2 mg·L-1NAA+6 mg·L-16-BA+8 g·L-1琼脂+30 g·L-1蔗糖)上不定芽再生率最高,达98.5%. 相似文献
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Tropepe V Coles BL Chiasson BJ Horsford DJ Elia AJ McInnes RR van der Kooy D 《Science (New York, N.Y.)》2000,287(5460):2032-2036
The mature mammalian retina is thought to lack regenerative capacity. Here, we report the identification of a stem cell in the adult mouse eye, which represents a possible substrate for retinal regeneration. Single pigmented ciliary margin cells clonally proliferate in vitro to form sphere colonies of cells that can differentiate into retinal-specific cell types, including rod photoreceptors, bipolar neurons, and Müller glia. Adult retinal stem cells are localized to the pigmented ciliary margin and not to the central and peripheral retinal pigmented epithelium, indicating that these cells may be homologous to those found in the eye germinal zone of other nonmammalian vertebrates. 相似文献
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不同基因型黄瓜离体再生及其影响因素的研究 总被引：2，自引：0，他引：2
以6个黄瓜(Cucumissativus L.)自交系为试验材料,研究不同的基因型、外植体类型和激素组合等因素对黄瓜离体植株再生的影响。结果表明,不同基因型黄瓜材料的再生能力差别较大;带柄子叶比下胚轴和不带柄子叶的再生率高,是比较理想的外植体材料;较低的6-BA/IAA配比促进黄瓜不定芽的分化;6-BA/IAA配比较高则适合再生芽的伸长;添加0.5mg/LAgNO3可以促进不定芽发生,5～6d苗龄的外植体分化再生频率较高;在供试的6个试验材料中,M8,M10的再生频率较强,分别达到96%和90%。高频率不定芽诱导分化培养基为:MS+IAA0.6mg/L+6-BA0.5mg/L+AgNO30.5mg/L;不定芽伸长的培养基为MS+IAA1.0mg/L+6-BA1.0mg/L+GA31.0mg/L+AgNO30.5mg/L;高效生根诱导培养基为MS+IAA0.2mg/L+NAA0.1mg/L。 相似文献
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[目的]研究不同生长调节因子及其浓度配比,对山药芽再生能力的综合效应,为建立山药茎尖脱毒苗体系提供基础数据。[方法]采用MS为基础培养基,选用6-BA、IBA、KT与CH为自变量,设计出不同生长调节因子浓度配比9个试验处理,以分化率、增殖系数（再生芽总数/外殖体数）与增殖速度为考察指标,研究其对山药芽再生能力的影响。[结果]4种生长调节因子对增殖系数与增殖速度的贡献效应分别为88.1%和92.4%,其贡献大小依次为6-BA〉IBA〉CH〉KT。[结论]6-BA与IBA对山药茎芽的再生,无论是静态的增殖系数还是动态的增殖速度,均表现出非常明显的生理分化效应。 相似文献
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以嘎拉(Royal Gala)苹果为供试材料,采用田间苗叶片和试管苗叶片及其试管苗茎段薄片作为外植体进行再分化比较试验研究。研究结果表明,不同外植体再分化的适宜培养基分别为:田间苗叶片以LS+BA 5.0 mg/L+IBA 0.3 mg/L培养基为宜;试管苗叶片以LS+BA 6.0 mg/L+IBA 0.3 mg/L培养基为宜;试管苗茎段薄片以LS+BA 5.0 mg/L+IBA 0.3 mg/L培养基为宜。在培养条件相同的情况下,苹果试管苗叶片再生能力明显高于田间苗叶片和试管苗茎段薄片,再生频率达70%以上。 相似文献