Subcellular trafficking of RNA

    Until recently, it was thought that the shape and polarity of a cell is controlled by the directed movements of proteins to the sites where they are needed. However, we have shown recently that much of subcellular protein distribution and subsequent activity is controlled by the trafficking of messenger RNAs prior to their conversion into protein. This was first shown with mRNA that encodes a secreted signaling molecule - Drosophila Wg/Wnt (Simmonds et al, 2001). We showed that localization of wg mRNA is required for the proper localization, processing, secretion and function of the highly conserved and important protein. Then, to see how prevalent and important the process of mRNA localization is overall, we embarked on a genome scale project to determine the localization of all mRNAs encoded in the Drosophila genome.

    First, we developed a highly sensitive, spatially accurate and high-throughput method for localizing mRNAs in whole embryos in high throughput. Thus far, we have completed analysis of approximately 1/3 of the fly genome. The results are surprising, with over 70% of mRNAs exhibiting subcellular localization, and with a large assortment of never seen before patterns. These initial results are described in Lecuyer et al, 2007 (editor's pick top paper of the year, Nature). A searchable database with images and descriptions of each mRNA pattern is provided at Fly-fish. We have also initiated analyses of localization in later stage embryos and 3rd instar larvae.

Watch this movie to see some examples


RNA - Green

DNA - Magenta