CHUNG, J. Sook*; ZMORA, N.; COMB, UMBI, Baltimore; COMB, UMBI, Baltimore: Crustacean cardioactive peptide: cDNA structures and expression patterns in crustaceans.

In arthropods, crustacean cardioactive peptide (CCAP) is conserved both in structure as a cyclized nonapeptide and in physiological functions: cardiac output and ecdysis. We employed a combined strategy of degenerate PCR and 3�-and 5�- RACE in order to obtain the full length of cDNA of CCAP from thoracic ganglia of the blue crab, Callinectes sapidus and crayfish, Orconetes immatus. The structure of cDNAs from these two species is similar, containing CCAP and 4 putative precursor associated peptides with unknown functions. The tissue distribution of CCAP gene expression and its differential expression in males and females were also investigated. CCAP expression was mostly found in CNS with the highest level in thoracic ganglia followed by similar amounts in brain and eyestalk. Eyestalks from females appeared to contain higher copy number of CCAP than those from males. As alluded to earlier, the function of CCAP during hatching, ecdysis and cardiac output has been described in Carcinus1,2. The level of CCAP in hemolymph reaches a nanomolar range at the completion of ecdysis, whereas the neuropeptide content of pericardial organs increases 2 fold at premolt stage. Thus, we are currently investigating the involvement of CCAP during ecdysis of the blue crab by measuring the translation and transcription levels of CCAP in the tissues and hemolymph. 1. Phlippins et al. (2000) J Exp Biol 203, 521-36. 2. Chung & Webster (2004) Development 131, 4751-4761.