The World of Small RNAs

RNA interference (RNAi), discovered and described in plants by our group in the late 1990s (Waterhouse et al 1998), has revolutionised plant and animal research. The technology gives researchers the ability to silence almost any gene, at will, and works by re-directing an intrinsic RNA-degrading mechanism that is present in almost all eukaryotic cells.

The main players in this pathway are the RNA-nucleases: Dicers and Argonautes. Humans have only one Dicer and 4 Argonautes. Plants have at least 4 Dicers and 10 Argonautes which produce and utilise different size classes of small RNAs. One of these Dicers produces ~21nt microRNAs that regulate development, another two produce 21 and 22nt siRNAs to fight against viruses, and another produces 24nt siRNAs that regulate gene expression through chromatin modification.

More recently, we have been investigating how, what and where miRNAs regulate developmental transitions, how and why sRNAs move, and the functions of the dsRNA binding (DRB) protein family.

The Nicotiana benthamiana Genome and Transcriptome

Nicotiana benthamiana is an exclusively Australian native plant which we, like many others around the world, use extensively for research. In 2010 we formed a consortium with like-minded colleagues at CSIRO Plant Industry (Canberra) and Plant & Food Research (New Zealand) to determine the sequence of the transcriptome and genome of this amazing plant. This sequence information is freely available to BLAST and GBrowse at our sister website. We find it an extremely useful resource (and fascinating subject) for our biotechnology, evolution, gene silencing, microRNA-regulation and epigenetic research.