Tan Xuqian, Boniuk Ethan, Abraham Anisha, Zhou Xueting, Yu Zhili, Ludtke Steven J, Wang Zhao
Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA.
Bioengineering Program, Rice University, Houston, TX 77030, USA.
Res Sq. 2025 Apr 28:rs.3.rs-5405930. doi: 10.21203/rs.3.rs-5405930/v1.
Electron cryo-tomography (cryo-ET) is a powerful imaging tool that allows three-dimensional visualization of subcellular and molecular architecture without chemical fixation. Tomogram quality varies widely, particularly during large high-throughput data collections, and the most common strategy for initial quality assessment is empirical judgment by an expert. Tomograms may be collected for two distinct purposes: annotation of subcellular features and cellular morphology, typically performed at lower magnifications and higher defocus, and subtomogram averaging, at high magnifications, closer to focus. For the first purpose, contrast and the ability to distinguish cellular features of interest are key, whereas for subtomogram averaging, recoverable signal at high resolution is the key factor. We have developed "TomoScore" a deep-learning based tomogram screening tool targeting cellular annotation. This tool provides a single quantitative measure of the suitability of a tomogram for annotation of subcellular features, in terms of the scale of features that can be readily distinguished. We further explore the relationship between accumulated electron dose and resulting quality, suggesting an optimum dose range for cryo-ET data collection. Overall, our study streamlines data processing and reduces the need for human involvement during pre-selection for tomogram segmentation.
电子冷冻断层扫描（cryo-ET）是一种强大的成像工具，可在不进行化学固定的情况下对亚细胞和分子结构进行三维可视化。断层扫描图的质量差异很大，尤其是在大规模高通量数据采集过程中，而初始质量评估最常用的策略是由专家进行经验判断。采集断层扫描图可能有两个不同目的：亚细胞特征和细胞形态的注释，通常在较低放大倍数和较高散焦条件下进行；以及在高放大倍数、更接近聚焦条件下进行亚断层图平均。对于第一个目的，对比度和区分感兴趣细胞特征的能力是关键，而对于亚断层图平均，高分辨率下可恢复的信号是关键因素。我们开发了 “TomoScore”，这是一种基于深度学习的针对细胞注释的断层扫描图筛选工具。该工具根据能够轻松区分的特征尺度，提供了一种对断层扫描图用于亚细胞特征注释适用性的单一量化度量。我们进一步探讨了累积电子剂量与所得质量之间的关系，提出了冷冻电子断层扫描数据采集的最佳剂量范围。总体而言，我们的研究简化了数据处理，并减少了在断层扫描图分割预选过程中对人工参与的需求。
