Piwi-interacting RNAs (piRNAs) and PIWI proteins play key functions in a wide range of biological and developmental processes through the regulation of cellular mRNAs, in addition to their role in transposable element (TE) repression. Evolutionary studies indicate that these PIWI functions in mRNA regulatory programs, occurring in both germ and somatic cells, are ancestral. Recent advances have widely expanded our understanding of these functions of PIWI proteins, identifying new mechanisms of action and strengthening their importance through their conservation in distant species. In this review, we discuss the latest findings regarding piRNA/PIWI-dependent mRNA decay in germ cells and during the maternal-to-zygotic transition in embryos combined with new modes of action of PIWI proteins in mRNA stabilization and translational activation and piRNA-independent roles of PIWI proteins in cancer.

piwi相互作用RNA（piRNA）和PIWI蛋白除了通过转座因子（TE）抑制作用外，还通过调节细胞mRNA在许多生物学和发育过程中发挥关键作用。进化研究表明，这些PIWI在生殖细胞和体细胞中都存在的mRNA调控程序中是祖先。最近的进展广泛地扩大了我们对PIWI蛋白功能的认识，确定了新的作用机制并通过在远处物种中的保存来增强了它们的重要性。在这篇评论中