A DGCR8-Independent Stable MicroRNA Expression Strategy Reveals Important Functions of miR-290 and miR-183-182 Families in Mouse Embryonic Stem Cells.

Dgcr8 knockout cells provide a great means to understand the function of microRNAs (miRNAs) in vitro and in vivo. Current strategies to study miRNA function in Dgcr8 knockout cells depend on transient transfection of chemically synthesized miRNA mimics, which is costly and not suitable for long-term study and genetic selection of miRNA function. Here, we developed a cost-effective DGCR8-independent stable miRNA expression (DISME) strategy based on a short hairpin RNA vector that can be precisely processed by DICER. Using DISME, we found that miR-294 promoted the formation of meso-endoderm lineages during embryonic stem cell differentiation. Furthermore, DISME allowed for a pooled screen of miRNA function and identified an miR-183-182 cluster of miRNAs promoting self-renewal and pluripotency in mouse embryonic stem cells. Altogether, our study demonstrates that DISME is a robust and cost-effective strategy that allows for long-term study and genetic selection of miRNA function in a Dgcr8 knockout background.