MicroRNA: biogenesis and computational target identification: a review.

MicroRNAs are a class of small, endogenously produced, 18 to 24 nucleotides long in length. These are non-coding RNAs that regulate the gene expression at post-transcriptional level. They play important roles in animals and plants by controlling regulatory mechanisms, and likely influencing the output of many protein-coding genes. They generally bind to 3' UTR region of the target sequence which then leads to alterations in the gene expression. They also bind to other regions like coding sequence and 5' UTR but these are less efficient sites of interaction compared to 3'UTR. This alteration in gene expression is either due to repression of translation or mRNA degradation whereby the RNA interference pathway is initiated to eliminate the targeted sequences. Now a days, various computational or bioinformatics databases, tools, and algorithms have been developed to identify the target genes which will be further biologically validated using various techniques like reporter gene assay, qRT-PCR, microarray etc. [ABSTRACT FROM AUTHOR]