Crustacean Cardioactive Peptide (CCAP) is a highly conserved, amidated cyclic nonapeptide, first isolated from the pericardial organs of the shore crab Carcinus maenas, where it has a role in regulating heartbeat; Crustacean Cardioactive Peptide (CCAP) also modulates the neuronal activity in other arthropods.
Ultrabithorax and Abdominal-A are not necessary for specification of the CCAP-interneurons, but are absolutely required to prevent the death by apoptosis of the CCAP-efferent neurons[2].
CCAP, FMRFamide and SALDKNFMRFamide increase the mosquito antennal accessory pulsatile organ (APO) and heart contraction rates, increase hemolymph flow velocity in the antennal space[1].
[1]. Suggs JM, et al. CCAP and FMRFamide-like peptides accelerate the contraction rate of the antennal accessory pulsatile organs (auxiliary hearts) of mosquitoes. J Exp Biol. 2016 Aug 1;219(Pt 15):2388-95. [2]. Moris-Sanz M, et al. The study of the Bithorax-complex genes in patterning CCAP neurons reveals a temporal control of neuronal differentiation by Abd-B. Biol Open. 2015 Aug 14;4(9):1132-42.