Analysis of Alternative Splicing Heterogeneity during Early Stages of Mouse Embryonic Development

Background: Pre-mRNA alternative splicing (AS) is a prevalent phenomenon in mammals, playing a crucial role in various biological processes such as embryonic development, tissue differentiation, and disease pathogenesis. Despite the advancements in single-cell RNA sequencing (scRNA-seq) technology, the extent of AS heterogeneity at the transcript level during early mouse embryonic development remains largely unexplored. Objective: The primary objective of this study is to reveal the heterogeneity of AS and elucidate its implications during early mouse embryonic development by analyzing AS at the single-cell level. Methods: The BRIE2 and Expedition were employed to identify and quantify splicing events. Cell clustering was performed with Scanpy based on Percent Spliced In (PSI) values and gene expression levels. Then, marker AS events and differential AS events were detected by the Wlicocon rank-sum test and BRIE2's Mode-2 quantification mode. GO and KEGG enrichment analysis were conducted by ClusterProfiler. Results: The results suggested substantial heterogeneity in AS events and elucidated PSI values as a critical index of cell heterogeneity during early mouse embryonic development, shedding light on the regulatory mechanisms underlying these processes. By examining marker and differential alternative splicing (AS) events, the study provided a comprehensive understanding of the dynamic changes in splicing patterns throughout early mouse embryonic development. Conclusion: This study revealed cellular heterogeneity of AS during early mouse embryonic development. The findings offer critical insights into studying mouse embryonic development from the perspective of RNA cellular heterogeneity, emphasizing the importance of AS in shaping cellular diversity and developmental processes.