Identification of the novel evolutionary conserved obstructor multigene family in invertebrates.

Insects have evolved chitin-containing structures such as the cuticle or peritrophic membranes that serve to protect their bodies against the hostile environment. The specific mechanisms by which these structures are produced, are mostly unknown. We have identified a novel multigene family, the obstructor family, which encodes ten putatively secreted chitin-binding proteins that are characterized by a stereotype arrangement of a N-terminal signaling peptide and 3 chitin-binding-domains. Gene expression studies in Drosophila melanogaster embryos demonstrate that obstructor family members are expressed in cuticle forming tissues. Using computational and phylogenetic analysis, we show that obstructor genes represent an evolutionary conserved multigene family in invertebrates.