Present status of in silico approach for micro-RNA identification

Abstract

MicroRNAs (miRNAs) are endogenous, small, noncoding RNAs of 18-25 nucleotides in length that negatively regulate their complementary messenger-RNAs at the post transcriptional level. Three methods are principally deployed to identify miRNA such as classic cloning, sequencing and computational approach. Computational approach is carried out mainly based on bioinformatics which is using small RNA library construction and sequencing to find miRNAs in the known genotypes (sequences). Another technique called the classical approach that is an example of forward genetics in which researchers determine the unknown genotype (miRNA sequence) of a known phenotype. The miRNAs have shown both evolutionarily converged nature (conserved miRNAs) from species to species within the same kingdom and species specific expression (species specific miRNAs). Majority of the miRNA genes are observed as conserved miRNAs as orthologs. This conserved nature of majority of miRNAs becomes an important logical tool for bioinformatics discovery of miRNAs in other species. Identification of miRNAs by using bioinformatics tools is now a commonplace and of the most widely used methods and it has facilitated the prediction of new miRNAs in both plant and animal systems. This is largely used due to its low cost and high efficiency.