Fig. 1
From: MicroRNA biogenesis and their functions in regulating stem cell potency and differentiation
Schematic illustration of microRNA (miRNA) biogenesis from transcription of a protein coding gene and from a miRNA gene. During miRNA biogenesis, a RNA transcript forms stem-loop primary-miRNAs (pri-miRNAs) that can be polycistronic or singular. The pri-miRNAs are processed into hairpin premature-miRNAs (pre-miRNAs) by Drosha. Pre-miRNAs are further cleaved into mature miRNAs by Dicer. Based on their origination, miRNAs can be classified into intragenic miRNAs that are originated from protein coding genes, and intergenic miRNAs that are originated from miRNA genes located between protein coding genes