MicroRNAs in embryonic stem cells and early embryonic development

MicroRNAs (miRNAs) are involved in the regulation of a broad range of biological processes. There is an extensive literature on the roles of miRNAs in metazoan development, from early embryogenesis to lineage commitment, and formation and maturation of cellular subtypes and complex tissues. This review will present the evidence that miRNAs are essential for the earliest stages of metazoan development, including establishment and maintenance of the pluripotent embryonic stem cells (ESCs) from which all foetal tissues arise. We will also discuss specific miRNAs that have been associated with early embryogenesis and pluripotency. Finally, we will point out evidence showing that there is strong and highly redundant miRNA regulation of a common set of target genes in the early stages of embryonic development and in ESCs.