A postulated role for microRNA in cellular differentiation.

Over the past two decades a variety of mechanisms regulating cellular differentiation have been uncovered. These include signaling by morphogens or membrane-associated ligands and asymmetric segregation of cytoplasmic components. Most of these processes are driven by protein coding genes. Here I describe another possible cellular differentiation mechanism that involves asymmetric segregation of microRNAs, a group of recently discovered non-protein coding genes that have been shown to be involved in differentiation.