Endo-siRNAs restrain proteasomes to sustain translation in oocytes

In a study published in Vita, Xue et al. show that endogenous siRNAs guide Argonaute proteins to suppress proteasome subunit expression in oocytes of C. elegans and mice. This regulation limits 26S proteasome assembly, preserves ribosomes, and enables the translation of transcription factors required for zygotic genome activation, revealing a conserved siRNA-proteasome-ribosome axis underlying the maternal-to-zygotic transition.