miRNA dynamics in development: orchestrators of gene expression and cell fate

MicroRNAs (miRNAs) are central regulators of gene expression, shaping cell fate, tissue identity, and organismal physiology. From the earliest stages of development through later processes of tissue differentiation, miRNAs operate within dynamic, context-dependent networks. Although the predominant role of miRNAs is to guide Argonaute-containing complexes to repress target mRNAs, the downstream consequences and mechanisms of action vary widely across developmental stages and tissue types. In this review, we examine the diverse roles of microRNAs in animal development across species and highlight emerging perspectives that are progressively refining our understanding of their function.