WDR74-Mediated Ribosome Biogenesis and Proteome Dynamics During Mouse Preimplantation Development

Preimplantation embryonic development is orchestrated by dynamic changes in the proteome and transcriptome, regulated by mechanisms such as maternal-to-zygotic transition. Here, we employed label-free quantitative proteomics to comprehensively analyze proteome dynamics from germinal vesicle oocytes to blastocysts in mouse embryos. We identified 3490 proteins, including 715 consistently detected across all stages, revealing stage-specific changes in proteins associated with translation, protein modification, and mitochondrial metabolism. Comparison with transcriptomic data highlighted a low correlation between mRNA and protein levels, underscoring the significance of non-transcriptional regulatory mechanisms during early development. Additionally, we analyzed WD repeat-containing protein 74 (WDR74)-deficient embryos generated using CRISPR-Cas9 genome editing. WDR74, a pre-60S ribosome maturation factor, was found to be critical for ribosome biogenesis and cell division. Furthermore, WDR74 deficiency led to a significant reduction in ribosomal protein large subunit and impaired progression beyond the morula stage. Key ribosomal proteins such as ribosomal protein L24 (RPL24) and ribosomal protein L26 (RPL26), which influence cell division timing, were notably affected, while small subunit proteins remained largely unchanged. Taken together, our study demonstrates the utility of integrating genome editing with proteomic analysis to elucidate molecular mechanisms underlying early embryogenesis, and provides new insights into protein-level regulation of preimplantation development.