The Wide Variety of miRNA Expression Profiles in the Developing and Mature CNS

Although microRNA (miRNA) expression is prominent in the central nervous system (CNS), very few miRNAs have been studied in detail in this system. We performed a comprehensive analysis of the neuroanatomical expression profiles of 38 abundantly conserved miRNAs in developing and adult zebrafish brain. We observed a wide variety of different miRNA expression profiles in neural cells, ranging from single cell types to the majority of CNS cells and from transient to constitutive expression. The survey of miRNA expression patterns suggested several modes of action within neural cells, such as function in neural stem cells/progenitors, clearance of target mRNAs at spatial or temporal transitions, silencing of aberrant transcription and spatial and/or temporal regulation of target mRNA translation within mature neural cells.