Functional diversity of a pheromonotropic neuropeptide: Induction of cuticular melanization and embryonic diapause in lepidopteran insects by Pseudaletia pheromonotropin

Abstract A pheromonotropic neuropeptide, Pseudaletia pheromonotropin, is an 18 amino acid peptide possessing PheThrProArgLeuNH 2 (FTPRLamide) at the C-terminus. Pseudaletia pheromonotropin and its fragment peptides were synthesized and tested for melanization and reddish coloration hormone (MRCH) activity as well as Bombyx diapause hormone activity by using Pseudaletia separata larvae and Bombyx mori pupae of the polyvoltine strain N 4 , respectively. Pseudaletia pheromonotropin had MRCH activity and the activity resided in the C-terminal FTPRLamide. Pseudaletia pheromonotropin also showed Bombyx diapause hormone activity, but the activity was estimated 1–5% of that of synthetic Bombyx diapause hormone. Based on the physiological function, Pseudaletia pheromonotropin is renamed Pseudaletia MRCH.