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微管骨架在轮藻节间细胞伸长生长中的作用 总被引:1,自引:0,他引:1
利用免疫荧光定位及激光共聚焦扫描显微镜,结合细胞生长曲线的定量测定,对不同生长阶段的轮藻节间细胞微管骨架进行了观察研究,结果如下:轮藻顶端生长活跃的新生细胞中,与细胞长轴垂直的周质微管(cortical microtubules)占绝对优势,随着生长速率的减慢,周质微管由垂直于细胞长轴逐渐转为平行排列;基部生长基本停止的节间细胞中,胞内微管则以平行细胞长轴为主;不同生长阶段节间细胞的微管骨架,对微管特异解聚剂黄草消(oryzalin)处理的敏感性表现不相同。顶端生长活跃的节间细胞经oryzalin处理40min后,绝大多数周质微管发生解聚;而基部生长基本停止的老细胞中,即使延长处理时间,仍残留一些尚未完全解聚的微管片段;10μmol/L微管解聚剂oryzalin处理轮藻顶端新生细胞,在高精度的细胞伸长生长测定装置监测下,发现oryzalin对细胞的伸长生长速率有明显的抑制作用,去掉药剂后,伸长生长又有一定的恢复。并且发现,经oryzalin处理后,微管的解聚(40min左右)与顶端节间细胞伸长生长的停止(100min左右)两者间存在着时间上的差异,即微管解聚在先,细胞伸长停止在后。以上结果均说明微管骨架在轮藻节间细胞生长中具有重要作用。 相似文献
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利用免疫荧光定位及激光共聚焦扫描显微镜,结合细胞生长曲线的定量测定,对不同生长阶段的轮藻节间细胞微管骨架进行了观察研究,结果如下:轮藻顶端生长活跃的新生细胞中,与细胞长轴垂直的周质微管(cortical microtubules)占绝对优势,随着生长速率的减慢,周质微管由垂直于细胞长轴逐渐转为平行排列;基部生长基本停止的节间细胞中,胞内微管则以平行细胞长轴为主;不同生长阶段节间细胞的微管骨架,对微管特异解聚剂黄草消(oryzalin)处理的敏感性表现不相同。顶端生长活跃的节间细胞经oryzalin处理40min后,绝大多数周质微管发生解聚;而基部生长基本停止的老细胞中,即使延长处理时间,仍残留一些尚未完全解聚的微管片段;10μmol/L微管解聚剂oryzalin处理轮藻顶端新生细胞,在高精度的细胞伸长生长测定装置监测下,发现oryzalin对细胞的伸长生长速率有明显的抑制作用,去掉药剂后,伸长生长又有一定的恢复。并且发现,经o-ryzalin处理后,微管的解聚(40min左右)与顶端节间细胞伸长生长的停止(100min左右)两者间存在着时间上的差异,即微管解聚在先,细胞伸长停止在后。以上结果均说明微管骨架在轮藻节间细胞生长中具有重要作用。 相似文献
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从以上叙述的资料中可以看出,近年来在植物微管蛋白的分离及其化学性质、微管的组织中心、微管的异质性、微丝的分布,以及微管和微丝骨架的功能及基因调节等方面的研究取得不少新的进展;特别是从植物中直接分离微管蛋白取得成功、以及微管蛋白异型、微管冷稳定性与植物抗寒性的关系及微丝分布广泛性等的发现,对植物细胞骨架的进一步研究具有重要意义。 相似文献
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脂筏(lipid raft)是细胞膜上富含胆固醇和鞘磷脂的微结构域(microdomain),参与细胞的多种生物学行为.随着研究的进一步深入,发现脂筏在真菌的极性生长方面也起着重要的作用.该文通过介绍真菌极性生长、脂筏的结构与功能等,阐述脂筏在真菌细胞极性生长中的作用,为阻断真菌极性生长并开发新的抗真菌药物靶点提供理论依据. 相似文献
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微丝骨架是细胞骨架的重要组成部分,它由肌动蛋白和肌动蛋白结合蛋白组成,广泛存在于真核细胞中。近年来,大量研究表明植物花粉及花粉管中存在丰富的微丝骨架。目前,在微丝骨架作为信号转导途径的靶标参与对花粉管极性生长的调控、微丝骨架在花粉和花粉管中的分布及其在花粉管生长过程中与其他信号分子之间的相互作用等方面取得了一系列突破性进展。 相似文献
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微管骨架在植物发育过程中起重要作用。由于植物细胞的特殊性,与动物细胞相比植物微管骨
架的研究遇到更多的困难。简略地介绍了曾被国内外学者应用的植物微管骨架的各种研究方法及其局限
性。Steedman's wax是一种多脂蜡。它熔点低(35~37℃),具有与石蜡相同的切片性质,能够切成不同厚
度的连续切片,适合深埋于器官内部的组织或细胞的免疫细胞化学研究。介绍了应用Steedman's wax 切
片法观察植物细胞微管骨架的一般程序和方法以及经过作者检验且切实可行的一些技术改进。 相似文献
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微管骨架在植物发育过程中起重要作用.由于植物细胞的特殊性,与动物细胞相比植物微管骨架的研究遇到更多的困难.简略地介绍了曾被国内外学者应用的植物微管骨架的各种研究方法及其局限性.Steedman's wax是一种多脂蜡.它熔点低(35~37℃),具有与石蜡相同的切片性质,能够切成不同厚度的连续切片,适合深埋于器官内部的组织或细胞的免疫细胞化学研究.介绍了应用Steedman's wax切片法观察植物细胞微管骨架的一般程序和方法以及经过作者检验且切实可行的一些技术改进. 相似文献
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New Feather-Degrading Filamentous Fungi 总被引:1,自引:0,他引:1
Rodrigues Marcondes N Ledesma Taira C Cirena Vandresen D Estivalet Svidzinski TI Kadowaki MK Peralta RM 《Microbial ecology》2008,56(1):13-17
Among 106 filamentous fungi isolated from poultry farm waste, 13 species belonging to seven genera (Aspergillus, Acremonium, Alternaria, Beauvaria, Curvularia, Paecilomyces, and Penicillium) were able to grow and produce keratinase in stationary cultures using poultry feather powder as the only substrate. The four most efficient keratinase producers were selected for a comparative study of keratinase production in submerged and stationary conditions. The highest keratinolytic activities were produced after 4-6 days of cultivation in submerged conditions: 53.8 +/- 6.1 U/mL (Alternaria tenuissima), 51.2 +/- 5.4 U/mL (Acremonium hyalinulum), 55.4 +/- 5.2 U/mL (Curvularia brachyspora), and 62.8 +/- 4.8 U/mL (Beauveria bassiana). These novel nondermatophytic keratinolytic fungi have potential use in biotechnological processes involving keratin hydrolysis. The results of this work contribute to show that keratinolytic activity is relatively widespread among common filamentous fungi and may have an important rule in feather decomposition in natural settings. 相似文献
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Chitinolytic Activity of Filamentous Fungi 总被引:1,自引:0,他引:1
The chitinolytic activity of nine species of filamentous fungi, classified with seven genera (specifically, Aspergillus, Penicillium, Trichoderma, Paecilomyces, Sporotrichum, Beaueria, and Mucor), was studied. When cultured in liquid medium containing 1% crystalline chitin, all fungi produced extracellular chitosans with activity varying from 0.2 U/mg protein (Sporotrichum olivaceum, Mucorsp., etc.) to 4.0–4.2 U/mg protein (Trichoderma lignorum, Aspergillus niger). 相似文献
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Effect of Substrate on the Fatty Acid Composition of Hydrocarbon-Utilizing Filamentous Fungi 总被引:4,自引:2,他引:2 下载免费PDF全文
A methionyl-specific dipeptidase from Streptococcus pneumoniae has been described. This enzyme and the pneumococcal tripeptidase have been shown to be intracellular, soluble, and constitutive. In addition to their function in cleavage of peptide nutrients, these peptidases may play a role in protein synthesis and turnover. 相似文献
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ABSTRACT:?Filamentous fungi are important organisms industrially and continue to attract research interest as microbiologists attempt to overcome the problems associated with their behavior in submerged culture. This review critically examines the literature describing these problems and where available suggests possible solutions to them. The influence of the chemical and physical environment on culture morphology, the process engineering challenges presented by different fungal morphologies, and the relationship between fungal morphology and metabolite production are all discussed. 相似文献
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García-Agudo L Aznar-Marín P Galán-Sánchez F García-Martos P Marín-Casanova P Rodríguez-Iglesias M 《Mycopathologia》2011,172(4):307-310
Otomycosis is common throughout the world but barely studied in Spain. Our objective was to determine the microbiological
and epidemiological characteristics of this pathology in Cadiz (Spain) between 2005 and 2010. Samples from patients with suspicion
of otomycosis underwent a direct microscopic examination and culture on different media for fungi and bacteria. Mycological
cultures were incubated at 30°C for at least seven days. Identification of fungi was based on colonial morphology and microscopic
examination of fungal structure. From a total of 2,633 samples, microbial growth was present in 1,375 (52.2%) and fungal isolation
in 390 (28.4%). We identified 228 yeasts and 184 filamentous fungi (13.4% of positive cultures and 47.2% of otomycosis), associated
with yeasts in 22 cases (5.6%). The most frequent species were Aspergillus flavus (42.4%), A. niger (35.9%), A. fumigatus (12.5%), A. candidus (7.1%), A. terreus (1.6%), and Paecilomyces variotii (0.5%). Infection was predominant in men (54.9%) and patients beyond 55 years old (46.8%). The most common clinical symptoms
were itching (98.9%), otalgia (59.3%), and hypoacusis (56.0%). Fall season reported the lowest number of cases (20.1%). Incidence
of otomycosis and fungi producing otomycosis vary within the distinct geographical areas. In Cadiz, this infection is endemic
due to warm temperatures, high humidity, sea bathing, and wind, which contributes to disseminate the conidia. Despite Aspergillus niger has been reported as the main causative agent, A. flavus is predominant in Cadiz. Although infection is usually detected in warm months, we observed a homogeneous occurrence of otomycosis
in almost all the seasons. 相似文献
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Methods developed for testing filamentous fungi (molds) include standardized broth microdilution (Clinical and Laboratory
Standards Institute [CLSI] and European Committee for Antimicrobial Susceptibility Testing [AFST-EUCAST]) methods and disk
diffusion (CLSI) methods. Quality control limits also are available from CLSI for MIC (minimal inhibitory concentration),
MEC (minimal effective concentration), and zone diameters. Although clinical breakpoints based on correlations of in vitro
results with clinical outcome have not been established, epidemiologic cutoff values have been defined for six Aspergillus species and the triazoles, caspofungin, and amphotericin B. The link between resistance molecular mechanisms, elevated MICs,
and clinical treatment failure has also been documented, especially for Aspergillus and the triazoles. Other insights into the potential clinical value of high MICs have also been reported. Various commercial
methods (e.g., YeastOne, Etest, and Neo-Sensitabs) have been evaluated in comparison with reference methods. This review summarizes
and discusses these developments. 相似文献
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