cer tain cuticle protein genes in the middle of the moult cycle. Additionally, two transcripts that displayed similarity to a low density lipoprotein receptor class A domain containing chitin binding protein NSC-330507 from Droso phila exhibited two different types of expression profiles, VER2 in Cluster E and VER3 in cluster D. The opposing expression profiles of Clusters D and E, together with the specificity of the transcript type identified in each cluster, suggests different physio logical roles and modes of action for VER2 and VER3. Differential expression of the hemocyanin gene family Transcripts belonging to the hemocyanin gene family represented 6% of all sequenced cDNAs, these include hemocyanin, cryptocyanin and metal lothionein.
Moult cycle related differential expression of hemocyanin and cryptocyanin was evident in Cluster B where high levels of expression are seen in the inter moult and pre moult Inhibitors,Modulators,Libraries stages. Recent studies examining global expression patterns of C. magister juveniles also found differential expression patterns occurring across developmental stages for both hemocyanin and crypto cycanin. Hemocyanin is an oxygen transport pro tein that is found in the hemolymph of crustaceans. In addition to its ability to reversibly bind oxygen, hemocyanin also displays PO activity which is important to the sclerotization or hardening of the newly synthesised cuticle. Hemocyanin has been located in the cuticle of the prawn Penaeus japonicus during the intermoult and postmoult stages of the moult cycle. Here the enzymatic activity of cuticular hemocyanin was higher than that of hemocyanin derived from the hemolymph.
Additionally, ecdysone has been found to bind to proteins within the crustacean hepatopancreas and cuticle. More recent studies on Inhibitors,Modulators,Libraries the tarantula, suggest that this Inhibitors,Modulators,Libraries protein may be hemocyanin. The spider hemocyanin was found to bind both Inhibitors,Modulators,Libraries ecdysone and 20 OH ecdysone, albeit with low affinity which is thought to be compensated for by its high concentration. The authors calculated that up to 75% of the ecdysteroids can be transported by hemocyanin. Considering the important role hemocyanin is thought to play in cuticle formation and ecdysone transport, the high levels of hemocyanin gene expression observed in the present study in both the intermoult and pre moult periods reflect the dual functionality of hemocyanin in preparation for arthropod ecdysis.
Cryptocyanin is structurally related to hemocyanin however it lacks the ability to bind oxygen. Instead cryptocyanin is involved in protein transport and in the formation of the new exoskeleton in crustaceans. The similarity in gene expression profiles of crytocyanin and hemocyanin, Cilengitide together with their structural related ness, suggests a similarity in function selleck with respect to cuticle synthesis, both through direct incorporation and the potential transfer of other cuticular components. Metallothionein on the other hand was up regulated gradually across the moult cycle where expression was lowes