| Imaging Microtubules in vitro at High Resolution while Preserving their Structure
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Author:
Date:
2021-04-05
[Abstract] Microtubules (MT) are the most rigid component of the cytoskeleton. Nevertheless, they often appear highly curved in the cellular context and the mechanisms governing their overall shape are poorly understood. Currently, in vitro microtubule analysis relies primarily on electron microscopy for its high resolution and Total Internal Reflection Fluorescence (TIRF) microscopy for its ability to image live fluorescently-labelled microtubules and associated proteins. For three-dimensional analyses of microtubules with micrometer curvatures, we have developed an assay in which MTs are polymerized in vitro from MT seeds adhered to a glass slide in a manner similar to conventional TIRF microscopy protocols. Free fluorescent molecules are removed and the MTs are fixed by perfusion. The MTs can ...
[摘要] [摘要]微管（MT）是细胞骨架中最刚性的组成部分。然而，它们在细胞环境中经常显得高度弯曲，并且控制它们整体形状的机理了解甚少。当前，体外微管分析主要依靠电子显微镜进行高分辨率分析，而全内反射荧光（TIRF ）显微镜则可以对活的荧光标记的微管和相关蛋白进行成像。为了对具有微米曲率的微管进行三维分析，我们开发了一种在体外聚合MT的检测方法 用类似于常规TIRF显微镜操作规程的方式将MT种子的MT粘附到载玻片上。除去游离的荧光分子，并通过灌注固定MTs。然后可以使用带有Airyscan模块的共聚焦显微镜观察MT，以获得更高的分辨率。该协议允许对保留其原始三维形状并与高分辨率免疫荧光检测兼容的微管进行成像。
[背景]微管（MT）是通过异源二聚体的组合制成的聚合物α和β微管蛋白，并且是细胞骨架的主要成分。他们参与了细胞功能的基本机制，如有丝分裂，细胞内转运，胞质分裂和细胞形态的维持（Akhmanova和Steinmetz，2015）。尽管MT本身具有很高的刚性，但它们通常会在细胞中弯曲并产生一些蛋白，从而弯曲微管（Brangwynne等人，2006; Bechstedt等人，2014; Leung等人，2020; Cuveillier等人，2020 ...
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| Mechanical Characterization of Glandular Acini Using a Micro-indentation Instrument
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Author:
Date:
2020-12-05
[Abstract] The linker of nucleoskeleton and cytoskeleton (LINC) complex is responsible for tethering the nucleus to the cytoskeleton, providing a pathway for the cell’s nucleus to sense mechanical signals from the environment. Recently, we explored the role of the LINC complex in the development of glandular epithelial acini, such as those found in kidneys, breasts, and other organs. Acini developed with disrupted LINC complexes exhibited a loss of structural integrity, including filling of the lumen structures. As part of our investigation, we performed a mechanical indentation assay of LINC disrupted and undisrupted MDCK II cells using a micro-indentation instrument mounted above a laser-scanning confocal microscope. Through a combination of force measurements acquired from the ...
[摘要] [摘要]的接头nucleoskeleton和细胞骨架（LINC）络合物负责核束缚到细胞骨架，提供用于细胞核从环境感测机械信号的通路。最近，我们探索了LINC复合物在腺上皮腺泡（例如在肾脏，乳房和其他器官中发现的腺泡）的发育中的作用。用破坏的LINC复合物开发的Acini表现出结构完整性的丧失，包括管腔结构的填充。作为研究的一部分，我们使用安装在激光扫描共聚焦显微镜上方的微型压痕仪对LINC破坏的和未破坏的MDCK II细胞进行了机械压痕测定。通过从微压痕仪获得的力测量值和从荧光图像获得的接触面积测量值的组合，我们确定了痤疮结构破裂的平均接触压力。在这里，我们提供了微压痕仪设计的详细描述，以及为执行这些生物压痕测量而开发的实验步骤。此外，我们讨论了确定痤疮结构破裂压力所需的数据分析步骤。尽管此协议专注于单个腺腺突的压痕，但此处介绍的方法可适用于针对2D和3D生物学系统执行各种机械压痕实验。
关键字：生物压痕，微压痕，生物力学，组织力学，核力学，LINC复合体，腺泡发育
[背景]生物压痕测试已成为手段长度尺度从亚细胞生物聚合物以多细胞组织结构来测量生物系统的材料性质。具有微米级探针和接触面积为10-100 nm 2的纳米压痕仪已用于测量生物聚合物和单个细胞的材料特性（Stolz等，2004； Sen等，2005； ...
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| Observing Nutrient Gradients, Gene Expression and Growth Variation Using the "Yeast Machine" Microfluidic Device
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Author:
Date:
2020-07-05
[Abstract] The natural environment of microbial cells like bacteria and yeast is often a complex community in which growth and internal organization reflect morphogenetic processes and interactions that are dependent on spatial position and time. While most of research is performed in simple homogeneous environments (e.g., bulk liquid cultures), which cannot capture full spatiotemporal community dynamics, studying biofilms or colonies is complex and usually does not give access to the spatiotemporal dynamics at single cell level. Here, we detail a protocol for generation of a microfluidic device, the “yeast machine”, with arrays of long monolayers of yeast colonies to advance the global understanding of how intercellular metabolic interactions affect the internal structure of colonies ...
[摘要] [摘要 ] 微生物细胞（如细菌和酵母菌）的自然环境通常是一个复杂的社区，在该社区中，生长和内部组织反映了形态发生过程和相互作用，这些过程和相互作用取决于空间位置和时间。虽然大多数研究是在无法捕获完整时空群落动态的简单同质环境（例如，大量液体培养）中进行的，但研究生物膜或菌落却很复杂，通常无法在单个细胞水平上获得时空动态。在这里，我们详细介绍了一种用于生成微流控设备（“酵母机器”）的协议，该协议带有酵母菌落的长单层阵列，以推进对细胞间代谢相互作用如何影响已定义和可定制的空间尺寸内菌落内部结构的全球了解。以酿酒酵母作为模型酵母系统，我们使用“酵母机器”通过追踪荧光标记的己糖转运蛋白来证明葡萄糖梯度的出现。我们进一步量化了菌落内生长速率的表达空间模式和葡萄糖可利用性调控的其他基因的表达。除此之外，我们显示出氨基酸的梯度也在菌落内形成，潜在地打开了类似的方法来研究许多其他营养物和代谢废物的梯度的时空形成。该方法将来可用于在与生态学和进化有关的单细胞分辨率和时标下，破译其他相同物种或更复杂的多物种系统中的远程代谢相互作用，细胞发育和形态发生之间的相互作用。
[背景 ] ...
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