Insect MicroRNAs: Biogenesis, expression profiling and biological functions

MicroRNAs (miRNA) are a class of endogenous regulatory RNA molecules 21–24 nucleotides in length that modulate gene expression at the post-transcriptional level via base pairing to target sites within messenger RNAs (mRNA). Typically, the miRNA “seed sequence” (nucleotides 2–8 at the 5′ end) binds complementary seed match sites within the 3′ untranslated region of mRNAs, resulting in either translational inhibition or mRNA degradation. MicroRNAs were first discovered in Caenorhabditis elegans and were shown to be involved in the timed regulation of developmental events. Since their discovery in the 1990s, thousands of potential miRNAs have since been identified in various organisms through small RNA cloning methods and/or computational prediction, and have been shown to play functionally important roles of gene regulation in invertebrates, vertebrates, plants, fungi and viruses. Numerous functions of miRNAs identified in Drosophila melanogaster have demonstrated a great significance of these regulatory molecules. However, elucidation of miRNA roles in non-drosophilid insects presents a challenging and important task.

Figure optionsDownload high-quality image (85 K)Download as PowerPoint slideHighlights
► MicroRNAs are a class of small RNA molecules that regulate gene expression post-transcriptionally.
► The discovery of microRNAs has added a new dimension to our understanding of complex gene regulatory networks.
► Biogenesis and function of microRNAs in Drosophila has been a heavily studied topic.
► Elucidation of microRNA roles in non-drosophilid insects presents a challenging and important task.