MicroRNA control of ground-s tate pluripotency

Ground-s tate pluripotency is a s tem-cell s tate achieved throughrepression of endogenous differentiation processes. The behaviorof embryonic s tem cells (ESCs) is influenced by ESCassociatedmicroRNAs (miRNAs). Here, we report a comprehensiveanalysis of the “miRNome” of ESCs maintained underconditions favoring ground-s tate pluripotency. Using small-RNA sequencing, we also determine the time-resolved profilesof miRNAs over the course of ground-s tate ESC derivation. Wefind that ground-s tate ESCs express a specific set of miRNAscompared to ESCs grown in serum. Interes tingly, the majorityof ground-s tate miRNAs are encoded by the imprinted Dlk۱-Dio۳ locus. Moreover, miRNAs, including the Dlk۱-Dio۳ miRNAs,are dynamically regulated during ESC derivation. Functionalanalysis reveal that Dlk۱-Dio۳ locus-embedded miRNAs (miR-۵۴۱-۵p, miR-۴۱۰-۳p, and miR-۳۸۱-۳p), miR-۱۸۳-۵p, andmiR-۳۰۲b-۳p promote, while miR-۲۱۲-۵p and let-۷d-۳p inhibitESC generation and/or maintenance. Collectively, these findingsoffer new mechanis tic insights into the role of miRNAsduring ESC derivation.