A Cryosectioning and Laser Microdissection Facility for Gene Metabolite and Protein Profiling from Pure Populations of Cells and Cell Types

激光显微解剖（LMD）是一项相对较新的技术，它正在彻底改变科学家分析生物过程的方式。它允许研究人员在显微镜下检查标本，用激光切割出一个精确的感兴趣的区域（一个细胞，也许是一个细胞集合），然后在不以任何方式污染它的情况下将切除的样本收集在一个管中。一旦样品被捕获，它可以根据需要进行广泛的化学分析。这包括对DNA、RNA、蛋白质和数千种其他细胞化学物质的分析，这些化学物质是生物过程的基础。对于许多化学物质（例如DNA和RNA），常规方法现在允许研究人员研究从单个细胞中分离出的微量物质。尽管所有类型的细胞都具有相同的基本化学成分，但正是它们之间的细微差异赋予了它们独特的特征和功能。它们表达不同的基因，构建不同的蛋白质，含有不同的活性分子。了解这些差异及其目的是生物科学许多领域的核心。如果没有LMD技术，研究人员通常不得不处理含有许多不同类型细胞的样本。这意味着单个细胞类型的独特特征很难或不可能辨别出来，因为它被几种细胞类型的存在所掩盖。因此，通常很难研究特定的局部事件，如细胞死亡、真菌感染或蛋白质或糖进出特定细胞的运输。虽然单个细胞可以用微针取样，如果它们很容易接近，但许多细胞隐藏在组织中，不能直接接触到。LMD解决了这些问题，因为它可以很容易地接触到任何材料的任何部分，这些材料可以切成薄片并安装在显微镜载玻片上。因为切片是从快速冷冻的组织中制备的（使用一种辅助设备，冷冻切片机），细胞在检查和激光解剖之前受到的干扰绝对最小。通过LMD进入这些细胞将有助于IGER研究人员更精确地了解关键的生物过程。IGER开展了广泛的研究，旨在支持有针对性地开发有利于农业和环境的新植物品种和农业方法。在其他条件相同的情况下，研究精度的提高将加快发现和发展的步伐。许多研究项目将直接受益于新设备。这些研究包括旨在了解特定基因在植物生长发育中的作用的研究，植物对胁迫的反应的研究，以及植物物质在农场动物瘤胃中分解时发生的相互作用的研究。这些研究项目对英国科学的关键目标至关重要，包括生物燃料可再生能源的开发和可持续农业的发展。LMD将用于分析特定植物细胞中的基因表达，重点关注诸如胁迫后植物衰老等领域。这将有助于正在进行的研究，这些研究正在研究不同类型的细胞如何在草的叶子中处理碳水化合物。真菌入侵过程中植物细胞间信号传递的研究也将受益。LMD将帮助研究人员研究微生物在瘤胃中对植物物质的定植，瘤胃是反刍动物消化的关键部分。具体来说，他们计划在定植过程中跟踪基因表达，并了解涉及哪些微生物物种。

Laser microdissection (LMD) is a relatively new technique that is revolutionising the way scientists analyse biological processes. It allows researchers to examine a specimen under the microscope, cut out a precise area of interest (a single cell, perhaps, or a collection of cells) with a laser, and then collect the excised sample in a tube without contaminating it in any way. Once the sample has been captured, it can be subjected to a wide spectrum of chemical analyses as required. These can include analyses of DNA, RNA, proteins and the thousands of other cell chemicals that are the foundation of biological processes. In the case of many chemicals (DNA and RNA, for example) routine methods now allow researchers to work with the tiny amounts of these substances that can be isolated from single cells. Although all cell types share their basic chemistry, it is the subtle differences between them that give them their unique character and functions. They express different genes, build different proteins and contain different suites of active molecules. Understanding these differences and their purpose is central to many areas of the biological sciences. Without the LMD technique, researchers often have to work with samples containing many different types of cells. This means that the unique character of individual cell types is difficult or impossible to discern, because it is masked by the presence of several types of cell. As a result, it is often difficult to study specific localised events such as cell death, fungal infection or transport of proteins or sugars in or out of specific cells. Although single cells can be sampled with a micro needle if they are easily accessible, many cells are hidden within tissues and cannot be reached directly. LMD answers these problems by allowing easy access to any part of any material that can be cut into thin slices and mounted on a microscope slide. Because the slices are prepared from quickly frozen tissue (using a supplementary piece of equipment, a freezing microtome), cells suffer the absolute minimum of disturbance before examination and laser dissection. Access to these cells via LMD will help IGER researchers to understand key biological processes with greater precision. IGER carries out a wide range of research designed to underpin the targeted development of new plant varieties and agricultural methods, which are better for farming and better for the environment. Other things being equal, increased precision in research will accelerate the pace of discovery and development. Many research projects will benefit directly from the new equipment. These include studies aimed at understanding the roles of specific genes in plant growth and development, studies on plant responses to stress, and studies on the interactions taking place when plant material is broken down in the rumen of farm animals. These research programmes are central to key aims of UK science, including development of renewable energy for biofuels and the development of sustainable agriculture. LMD will be used to analyse gene expression in specific plant cells, focusing on areas such as plant senescence following stress. It will contribute to ongoing studies that are examining the way different types of cell process carbohydrate in the leaves of grasses. Studies on signalling between plant cells during fungal invasion will also benefit. LMD will help researchers study colonisation of plant material by microorganisms in the rumen, a key part of digestion in ruminant animals. Specifically, there are plans to follow gene expression during colonisation and to understand what microbial species are involved.