SEGMENTATION SOFTWARE FOR CRYOEM

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 使用电子显微镜确定细胞机器的分子结构的关键步骤是能够在三维密度图中识别单个分子。 这些分子紧密地堆积在一起，使得它们的边界难以辨别。 分割是确定不同分子的密度图区域的过程。 我们已经开发了一个名为Segger的UCSF Chimera插件，该插件使用基于分水岭算法的自动计算来分割地图，并允许手动编辑结果，以修复由预期结构的额外专家知识指导的不可避免的错误。 重点一直是通过单粒子电子冷冻显微镜研究孤立的分子组装体的电子显微镜，并且有强烈的兴趣扩展该软件也能够分割拥挤的细胞环境，其中大量不同的分子组装体被包装在一起。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. A key step in determining the molecular architecture of cellular machinery using electron microscopy is being able to identify the individual molecules in 3-dimensional density maps. The molecules are tightly packed together making their boundaries hard to discern. Segmentation is the process of determining the regions of density maps for different molecules. We have developed a plug-in to UCSF Chimera called Segger that segments maps using automated computations based on the watershed algorithm, and allows hand-editing of the results to fix the inevitable mistakes guided by additional expert knowledge of the expected structures. The focus has been on electron microscopy of isolated molecular assemblies studied by single-particle electron cryo-microscopy, and there is strong interest in extending the software also be able to segment crowded cellular environments where a large number of diverse molecular assemblies are packed together.