Live-cell Imaging and Quantitative Analysis of Meiotic Divisions in Caenorhabditis elegans Males
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Author:
Date:
2020-10-20
[Abstract] Live-imaging of meiotic cell division has been performed in extracted spermatocytes of a number of species using phase-contrast microscopy. For the nematode Caenorhabditis elegans, removal of spermatocytes from gonads has damaging effects, as most of the extracted spermatocytes show a high variability in the timing of meiotic divisions or simply arrest during the experiment. Therefore, we developed a live-cell imaging approach for in situ filming of spermatocyte meiosis in whole immobilized C. elegans males, thus allowing an observation of male germ cells within an unperturbed environment. For this, we make use of strains with fluorescently labeled chromosomes and centrosomes. Here we describe how to immobilize male worms for live-imaging. Further, we describe ...
[摘要] [摘要] 用相差显微镜对一些物种的精母细胞进行了减数分裂的实时成像。对于秀丽隐杆线虫来说,去除生殖腺中的精母细胞具有破坏性作用,因为大多数精母细胞在减数分裂的时间上表现出高度的变异性,或者只是在实验中停止。因此,我们开发了一种活体细胞成像方法,用于原位拍摄固定化线虫雄性精母细胞减数分裂过程,从而可以在不受干扰的环境中观察雄性生殖细胞。为此,我们利用带有荧光标记染色体和中心体的菌株。在这里我们描述如何固定男性蠕虫进行实时成像。此外,我们描述了获取和处理数据的工作流程,以获得有关精母细胞减数分裂I和II中染色体分离动态的定量信息。此外,我们最新开发的方法允许我们在电子显微镜中重新定位胶片上的主轴,而不管蜗杆的初始3D方位如何,并以统计稳健的方式分析活蠕虫的纺锤动力学。我们的实时成像方法也适用于秀丽隐杆线虫雌雄同体,并且可以扩展到其他荧光标记的线虫或其他完全透明的小型模型生物。 [背景] ...
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Identification and Quantification of Secondary Metabolites by LC-MS from Plant-associated Pseudomonas aurantiaca and Pseudomonas chlororaphis
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Author:
Date:
2018-01-20
[Abstract] Increased antibiotic resistance of plants and human pathogens and continuous use of chemical fertilizers has pushed microbiologists to explore new microbial sources as potential antagonists. In this study, eight strains of Pseudomonas aurantiaca and Pseudomonas chlororaphis, have been isolated from different plant sources and screened for their antagonistic and plant growth promoting potential (Shahid et al., 2017). All strains were compared with reference strain PB-St2 and their secondary metabolites were isolated by the use of solvent partitioning and subjected to LC/ESI/MS for confirmation of compounds. The ESI-mass spectra obtained were used to characterize the surfactants ionization behavior and [M + H]+ and [M + Na]+ ions were ...
[摘要] 哺乳动物正呼吸道病毒(呼肠孤病毒)利用成孔肽穿透宿主细胞膜。 在病毒进入过程中,这一步对于提供含核心颗粒的基因组至关重要。 该协议描述了用于测量呼肠孤病毒诱导的孔形成的体外测定。
【背景】呼肠孤病毒是无包膜的双链RNA病毒,其由两个同心蛋白质壳组成:内衣壳(核心)和外衣壳(Dryden等人,1993; Zhang等人, / ,2005; Dermody et al ,2013)。在附着之后,病毒颗粒被内吞(Borsa et al。,1979; Ehrlich et al。,2004; Maginnis et al。,2006; Maginnis和宿主组织蛋白酶蛋白酶降解σ3外壳蛋白(Chang和Zweerink,1971; Silverstein等人,1972; Borsa等人,et al。 1981; Sturzenbecker等人,1987; Dermody等人,1993; Baer和Dermody,1997; Ebert等人, 2002年)。这个过程产生一个亚稳中间体,称为感染性亚病毒颗粒(ISVP),其中细胞穿透蛋白μ1被暴露(Dryden等人,1993)。呼肠孤病毒ISVPs进行第二次构象改变以将含有基因组的核心沉积到宿主细胞的细胞质中。被改变的粒子被称为ISVP *(Chandran et al。,2002)。 ISVP-to-ISVP ...
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Genome Editing in Diatoms Using CRISPR-Cas to Induce Precise Bi-allelic Deletions
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Author:
Date:
2017-12-05
[Abstract] Genome editing in diatoms has recently been established for the model species Phaeodactylum tricornutum and Thalassiosira pseudonana. The present protocol, although developed for T. pseudonana, can be modified to edit any diatom genome as we utilize the flexible, modular Golden Gate cloning system. The main steps include how to design a construct using Golden Gate cloning for targeting two sites, allowing a precise deletion to be introduced into the target gene. The transformation protocol is explained, as are the methods for screening using band shift assay and/or restriction site loss.
[摘要] 最近为三角褐指藻(Phaeodactylum tricornutum)和海绵假丝酵母(Thalassiosira pseudonana)建立了硅藻基因组编辑。 目前的协议,虽然开发的 T。 pseudonana ,可以修改编辑任何硅藻基因组,因为我们利用灵活,模块化的金门克隆系统。 主要步骤包括如何设计构建使用金门克隆靶向两个网站,允许一个精确的删除被引入目标基因。 解释转化方案,以及使用带移位测定和/或限制性位点丢失进行筛选的方法。
【背景】CRISPR-Cas正在迅速成为分子研究的一个关键方法。基于在细菌和古细菌中发现的病毒防御机制,CRISPR-Cas诱导基因组中精确位置的双链断裂(DSBs)。它涉及使用与CRISPR ...
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