In response to crowding, locusts develop characteristic black patterns that are well discernible in the gregarious phase at outbreaks. We report here a dark-color- inducing neuropeptide (dark-pigmentotropin) from the cor- pora cardiaca of two plague locusts, Schistocerca gregaria and Locusta migratoria. The chromatographic isolation of this neuropeptide was monitored by using a hioassay wilh an alhino mutant of L. migratoria. The neurohormone consisting of 11 amino acids, is identical [His~7] corazonin previously isolated from corpora cardiaca of another acrtdid without known function. The present results show that even in isolated (solitary) nymphs, [His~7] corazonin induces gregarious black patterns. lts primary structure shows some similarity with the vertebrat melanophore stimulating hormone.
展开▼
