Immunocytochemical identification of crustacean hyperglycemic hormone-producing cells in the brain of a freshwater fairy shrimp,Streptocephalus dichotomus Baird (Crustacea: Anostraca)

Localization of crustacean hyperglycemic hormone (CHH) activity in the brain ganglia of Streptocephalus dichotomus was demonstrated by immunocytochemical method. For this, two different rabbit antisera, one raised against a crayfish Orconectus limosus, and the other with a crab Carcinus maenas, were used. Positive immunoreactivity was recorded with the antibody raised against Orconectus limosus CHH. However, the antibody raised against the CHH of the crab, Carcinus maenas failed to show any cross-reactivity. The biological specificity of these peptides was further confirmed by immunoblotting and immunodiffusion studies performed with the partially purified CHH. The results obtained with the immunodot-blotting and immunodiffusion studies with CHH, further confirmed the immunocytochemical studies. Bioassay experiments performed with a freshwater prawn, Macrobrachium rosenbergii indicate the interspecific biological activity of this neuropeptide. The present study indicates that besides the sinus gland, there are other sites of CHH synthesis and release in the brain ganglia of S. dichotomus.