The Biochemical Diversity of the Second-stage Juvenile Cuticle: It's Origin, Role and Interaction with Pasteuria Endospores

Over the last 20 years or so, Caenorhabditis elegans has been used as a model to understand aspects of innate immunity and a number of genes have been identified that play a possible role in microbial infection processes. One group of these genes appear to express proteins that can be classified as mucins which are highly glycosylated. Recent in silico investigations have shown that many mucins present in C. elegans also have homologs in plant-parasitic nematodes and several of them have been shown to be expressed in seam cells before they are then transported to the cuticle surface coat where they appear to affect microbial adhesion. Research will be presented that shows that knockdown of a mucin identified in Meloidogyne incognita resulted in altered Pasteuria endospore binding, however this was not the only gene that when knockdown affected endospore binding. These results suggest that collagen-like adhesins on the surface of the endospore are interacting with a complex set of receptors on the cuticle. A model will be presented that will account for the host – parasite specificity observed between the nematode cuticle and Pasteuria endospores and the role that plant exudates may play in the manipulation of this highly specific interaction.