Secrets of the Blue Crab Exoskeleton: Investigating the Control of Cuticle Mineralization Using a Transcriptome Approach
Tom Shafer, Dept. of Biology and Marine Biology, University of North Carolina, Wilmington
20 Oct 2006
Decapod crustaceans, like all arthropods, must molt in order to grow. But unlike the more thoroughly studied insects, crabs and lobsters undergo extensive calcification of each new exoskeleton. This provides an opportunity to investigate the temporal and spatial control of mineralization. The rapid and predictable calcium deposition provides a model for biomineralization that may be more amenable to investigation than analogous phenomena in other groups of animals. Because we are discovering the morphological details of the steps involved in postmolt CaCO3 deposition in Callinectes sapidus, the blue crab, and because we have produced a reasonably large dataset of expressed sequence tags for this species, we are in a position to investigate gene products regulating the mineralization process. This seminar will focus on (a) our approaches to mine the transcriptome data for sequences coding for cuticular proteins, (b) our data on expression patterns across the molt cycle in dorsal cuticle (that will calcify) versus joint cuticle (that will not), and (c) our attempts to combine comparative sequence analysis and expression data to hypothesize which of several dozen exoskeletal proteins may actually function as calcification regulators. We will also discuss progress on developing an RNA interference assay to more directly assess the functions of the gene products.