SURROGATE GENETICS FOR XYLELLA FASTIDIOSA

• Author(s): Stewart, Valley; Kirkpatrick, Bruce;
• Abstract: Xylella fastidiosa presents a formidable challenge to the molecular geneticist. Methods for the basic operations of genetic exchange, mutant isolation, and complementation are in early stages of development. The slow generation time, poor plating efficiency and requirement for complex culture media are further complications. Surrogate genetics (Maloy and Zahrt 2000) provides a means to at least partially bypass these challenges. Here, one creates a hybrid organism, transplanting genes of interest from the poorly-studied species (e.g., Xylella fastidiosa) into a well-studied surrogate host (e.g., Escherichia coli). Given sufficiently related hosts, one expects the transplanted genes to function in the surrogate essentially as they do in the original. One may then exploit the advantageous properties of the surrogate to perform a large number of experiments, making and discarding hypotheses to define various aspects of gene function. Once gene function in the surrogate has been thoroughly explored, one can perform a focused set of experiments, informed by the results from the surrogate, to examine function in the native host. The use of E. coli as a surrogate host for studying gene regulation would open a range of experimental approaches that are currently unavailable in X. fastidiosa, and lead to more rapid advances in understanding the control of key pathogenicity determinants. We are analyzing the transcriptional regulation determinants for genes whose products may be involved in pathogenesis (e.g., pil genes, encoding type IV pili) as well as "housekeeping" genes involved in central metabolism (e.g., amino acid biosynthesis).
• Publication Date: Dec 2002
• Journal: 2002 Pierce's Disease Research Symposium