Identification and characterisation of crustacean hyperglycaemic hormone (CHH) from Mediterranean shore crab Carcinus aestuarii

Crustacean hyperglycaemic hormone (CHH) is a neuropeptide that was originally identified in the X-organ/sinus gland complex of the eyestalks (ESs) incrustaceans. Several CHH isoforms and spliced variants were later identified in other tissues, and their functions have still not been completely unveiled. In this study,the identification and characterisation of the conventional CHH prepropeptide from the ESs of the littoral crab, Carcinus aestuarii, via rapid amplification of cDNA ends was reported.The identified CHH resulted in a coding sequence of 429 bp, an estimatedprotein of 142 aa with a signal peptide of 26 aa, followed by a CHH precursorrelated peptide of 40 aa and a mature peptide of 72 aa. The amino acid sequence of C.aestuarii CHH was also compared, by similarity, with CHHs from Brachyura infraorder, which showed the highest similarity (98.6%) to the CHH peptide from Carcinus maenas. None of CHH members were reported from this species and being proved by several studies that CHH is produced also during stress conditions, the identification of the full length of the CHH in C. aestuarii opens a new wayin the possibly of studying stress response in Mediterranean shore crab by monitoring of the neuropeptide expression.