The spe cific up regulation of these cuticle trancripts in the intermoult phase indicates that formation and or repair of the exoskeleton may continue throughout the inter moult phase and that these genes operate selleck kinase inhibitor separately to those involved in the formation of new cuticle during the pre and post moult stages. The largest proportion of cuticle protein transcripts was found to occur inatus gastrolith protein. Here we see an expression profile of up regulation in the moult and post moult stages then a sharp decline during intermoult and early pre moult, followed by a recovery in the late pre moult stage. GAP65 was found to be directly involved in the deposi tion of amorphous calcium carbonate in the gastroliths of C. quadricarinatus.

Based on the expression pro file observed for transcripts VER3 and GAP65 in Cluster D, a role in the calcification of the crustacean cuticle seems likely. A similar pattern is seen in Cluster F which contains 13% cuticle protein transcripts, composed of P. pelagicus cuticle protein BD2 and CBM. Transcripts with the abbreviation BD, code for proteins with a PfamB 109992 domain which has yet to be annotated but has been isolated from the calcified cuti cle of other crabs. CUT transcripts, when trans lated, contain the protein domain cuticle 1, also associated with calcified cuticle. CB transcripts, on the other hand, code for proteins with a chitin bind 4 domain. In addition to its chitin binding function, this chitin binding domain also occurs in proteins which have been demonstrated to function in calcification of the crustacean exoskeleton.

CMB is another transcript group with chitin binding abilities, prevalent in insects and involved in the structural formation of the peritrophic membrane, it has also been found in penaeid prawns. Despite the differences in domain type, and hence assumed functional difference, these tran scripts follow a synergistic pattern of expression, which displays up regulation at ecdysis with a peak in post moult. The high level of expression in post moult together with functional annotation suggest that these genes are involved in the synthesis and hardening of the post moult crustacean cuticle. P. pelagicus cuticle pro tein CUT7 and CB4, observed in Cluster G, present with a slightly different profile where expression is highest in post moult and inter moult, decreases dramatically in early pre moult then begins to increase again in late pre moult.

The incidence of cuticular protein up regulation in intermoult, when compared to early pre moult, is per haps unexpected because the exoskeleton is considered to be fully formed by the intermoult stage. This may indicate a continued synthesis and or repair of the exoskeleton well into the intermoult period followed by a down regulation of cuticular protein expression in the Cilengitide pre moult period, in preparation for the degradation and eventual shedding of the exoskeleton at ecdysis.