MicroRNAs (miRNAs) are small, endogenously, non-coding genes that regulate protein production either by mRNA cleavage or by translational repression in eukaryotes and viruses. miRNAs plays a key role in biological processes including growth, development and physiology of an organism. In this study, we employed insilico approaches to identify the miRNAs from Spodoptera frugiperda, a major pest of small grain crops. A total of seven miRNAs were identified and characterized from 67,360 expressed sequence tags (ESTs) of S. frugiperda with: 1) mature and pre-miRNAs sizes vary from 19 to 25 ans 61 to 95 nucleotides respectively; 2) minimum free energy ranged from -31.70 to -21.00 kcal/mol; and 3) (A + U) content varied from 27 to 60. The functional annotation of these miRNAs were identified as regulation of transcription factors, catalytic activities and signal transduction pathways. Further studies of these miRNAs will help to carryout functional analyses, which promises more towards insect pest management free of insecticides and pesticides.
Key words: MicroRNAs, translational repression, Spodoptera frugiperda, expressed sequence tags, minimum free energy, insect pest management.