Small non-coding RNAs produced through various pathways play important roles in different biological processes in eukaryotes. In particular, microRNAs as ~22 nucleotide long small RNAs regulate gene expression at transcriptional and post-transcriptional levels by interacting with their target sequences based on sequence complementarity. While functional miRNAs and other small non-coding RNAs of less than 50 nt have been found in almost all eukaryotes, only very recently they have been reported from a small number of bacteria.
Wolbachia is an endosymbiotic bacterium found in about 40-65% of insect species, and is mostly known for reproductive manipulations of its host. In addition, some strains of Wolbachia block virus replication in infected insects, which has led to their utilization in blocking virus transmission in mosquito vectors. While effects of Wolbachia on its host have been known for decades, in particular reproductive manipulations, the molecular mechanisms behind these manipulations are largely unknown. Using microarrays and next generation sequencing followed by bioinformatics and experimentation, we have found that host miRNAs and Wolbachia miRNA-like small RNAs play important roles in the symbiont-mosquito interaction facilitating its maintenance in the host. This presentation will provide an overview of the role of miRNAs in the interactions with an emphasis on Wolbachia-derived small non-coding RNAs.