Presence Of [His(7)]-Corazonin In The Central Nervous System Of A Newly Isolated Albino Strain Of Schistocerca Gregaria (Orthoptera : Acrididae) - Mass Spectrometric And Immunocytochemical Evidence

An inbred strain of a newly isolated spontaneous albino mutant of Schistocerca gregaria (Forsk.) was examined for the presence of the neuropeptide [His(7)]-corazonin by immunocytochemical and mass spectrometric methods. It was concluded that this peptide is definitely present in a limited number of neurosecretory cells in the pars lateralis as well as in the corpora cardiaca (CC). Injection of either synthetic [His(7)]-corazonin or of extracts of CC of the normal coloured phenotype of S. gregaria failed to induce darkening of the cuticle, while albino Locusta migratoria, used as a positive control, turned dark. The conclusion is that the cause of albinism in the new S. gregaria albino is probably due to a defect in the receptor system for [His(7)]-corazonin or in the biosynthetic pathway of melanin.