Molecular evolution of the crustacean hyperglycemic hormone family in ecdysozoans
The neuroendocrine system of Euscorpius carpathicus was immunohistochemically localized using a polyclonal antiserum raised against a purified Homarus americanus crustacean hyperglycemic hormone (Hoa-cHHA). There were cross-reactions in E. carpathicus procerebral and subesophageal neurosecretory cells, neurohemal organs, and intra- and extraganglionic neurosecretory tracts. Among the neurohemal structures, the Kwartirnikov's organ, the Tropfenkomplex, and the coxal disc reacted strongly. In Euscorpius, the differing results between adults and juveniles suggest neurosecretory variations related to developmental stage. These immunohistochemical observations suggest the presence of substances related to the cHH in scorpions; however, in this heterologous system, it is not at present possible to assess physiological significance.