Gravato-Nobre, Maria J. et al. (2009) International Worm Meeting "C. elegans invertebrate-type lysozyme genes: an investigation into their expression, inducibility and function."

Hodgkin, Jonathan, Marsay, Teresa, Stroud, Dave, Gravato-Nobre, Maria J., Wong, Suet L

[International Worm Meeting, 2009]

C. elegans is a bacterial-feeder that spends its entire life cycle in decaying organic matter. In such an environment laden with infectious microorganisms, the worm depends on an effective digestive system capable of filtering, degrading and hydrolysing bacterial cells, and an inducible immune response capable of secreting potent antimicrobial effectors. Lysozymes have an important dual role acting both in digestion and defence. In addition to 10 classical lysozyme genes (lys-1-lys-10) the C. elegans genome encodes 5 invertebrate type lysozymes (ilys-1-5) whereas the related species C. briggsae, C. remanei contain only two and three ilys genes, respectively. Microarray analysis has previously shown that a cluster of three invertebrate lysozymes in C. elegans, ilys-3, ilys-2 and to a lesser extent ilys-1, are upregulated in response to infection by M. nematophilum. To provide further insights into the role of C. elegans i-lysozymes ilys-1 to ilys-5, we have undertaken different approaches that combine genome sequencing of many wild isolates, reporter constructs and RNAi assays. We find that all the Cel ilys genes are generally expressed in the worm''s digestive tract. However, their exact expression pattern differ slightly, with notably distinct pattern of pharyngeal expression which suggests that these genes might have evolved separate functions. To investigate if the Cel ilys genes play a role in host-pathogen defence response, we developed inducibility assays using a number of different bacterial pathogens The differential up-regulation of the Cel ilys genes will be reported. In addition, we have analysed knockdowns and knockouts of ilys genes and will discuss natural variation in the ilys-1 locus.