Deciphering tRNA repertoires and translation coordination during mouse early embryogenesis by ORACLE-tRNAseq.

Li, Yun; Wang, Xin; Huang, Ruofan; Yu, Haoquan; Wu, You; Shu, Ze; Jiang, Wenlin; Cao, Zheng et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

Translational control is vital during the maternal-to-zygotic transition (MZT), yet the landscape of embryonic transfer RNA (tRNA) pools has been difficult to explore. Here, we develop Optimized Reaction for Accurate Capture of Low-input Entities tRNA Sequencing (ORACLE-tRNAseq), enabling robust tRNA profiling from as few as five mouse oocytes. We map tRNA landscapes from oocyte to blastocyst, identifying a distinct transition to embryonic tRNA repertoires and upregulation of tRNA pseudogenes at the 4-cell stage. Integrated multi-omics analyses reveal that zygotic tRNA gene activation coincides with zygotic genome activation (ZGA) and correlates with H3K4me3 establishment and chromatin remodeling. By coupling ORACLE-tRNAseq with Ribo-seq, we demonstrate that embryonic tRNA anticodon pools coordinate with high translation-efficiency gene pools to preferentially establish the zygotic translation machinery, particularly from major ZGA onwards. Collectively, these findings provide a resource for understanding translational regulatory networks during early embryogenesis.