Embryonic stem cell miRNAs and their roles in development and disease.

MicroRNAs have emerged as important modulators of gene expression. Both during development and disease, regulation by miRNAs controls the choice between self-renewal and differentiation, survival and apoptosis and dictates how cells respond to external stimuli. In mouse pluripotent embryonic stem cells, a surprisingly small set of miRNAs, encoded by four polycistronic genes is at the center of such decisions.

Germline deletion of the miR-17∼92 cluster causes skeletal and growth defects in humans.

MicroRNAs (miRNAs) are key regulators of gene expression in animals and plants. Studies in a variety of model organisms show that miRNAs modulate developmental processes. To our knowledge, the only hereditary condition known to be caused by a miRNA is a form of adult-onset non-syndromic deafness, and no miRNA mutation has yet been found to be responsible for any developmental defect in humans.