Semantic segmentation-based detection algorithm for challenging cryo-electron microscopy RNP samples

Front Mol Biosci. 2024 Oct 1:11:1473609. doi: 10.3389/fmolb.2024.1473609. eCollection 2024.

Abstract

In this study, we present a novel and robust methodology for the automatic detection of influenza A virus ribonucleoproteins (RNPs) in single-particle cryo-electron microscopy (cryo-EM) images. Utilizing a U-net architecture-a type of convolutional neural network renowned for its efficiency in biomedical image segmentation-our approach is based on a pretraining phase with a dataset annotated through visual inspection. This dataset facilitates the precise identification of filamentous RNPs, including the localization of the filaments and their terminal coordinates. A key feature of our method is the application of semantic segmentation techniques, enabling the automated categorization of micrograph pixels into distinct classifications of particle and background. This deep learning strategy allows to robustly detect these intricate particles, a crucial step in achieving high-resolution reconstructions in cryo-EM studies. To encourage collaborative advancements in the field, we have made our routines, the pretrained U-net model, and the training dataset publicly accessible. The reproducibility and accessibility of these resources aim to facilitate further research and validation in the realm of cryo-EM image analysis.

Keywords: cryo-electron microcopy; image proceesing; influenza a virus; particle picking; semantic segmantation.

Grants and funding

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. Authors want to acknowledge economical support from the Spanish Ministerio de Ciencia e Innovación, Grant PID2022-137548OB-I00 funded by MCIN/AEI/10.13039/501100011033/ and by ERDF A way of making Europe (to JV). Grant PID2020-117752RB-I00 financed by MCIU/AEI/10.13039/501100011033 and FEDER, UE (to JM-B) and grant TED2021-132748B-I00 financed by the European Union “Next-Generation EU”/PRTR (to JM-B and JV). CNB-CSIC acknowledges support from the Severo Ochoa Program for Centers of Excellence in R&D (CEX2023-001386-S).