SYNTHESIS OF NOD-LIKE CHITIN OLIGOSACCHARIDES BY THE XENOPUS DEVELOPMENTAL PROTEIN DG42

The Xenopus DG42 gene is expressed only between the late midblastula a nd neurulation stages of embryonic development. Recent database search es show that DG42 has striking sequence similarity to the Rhizobium No dC protein. NodC catalyzes the synthesis of chitin oligosaccharides wh ich subsequently are transformed into bacterium-plant root signaling m olecules. We find that the DG42 protein made in an in vitro coupled tr anscription-translation system catalyzes the synthesis of an array of chitin oligosaccharides. The result suggests the intriguing possibilit y that a bacterium-plant type of ''Nod'' signaling system may operate during early stages of vertebrate embryonic development and raises iss ues about the use of chitin synthase inhibitors as fungal-specific dru gs.