Insulin-like peptides in model insects

Recent years, invertebrate animals with clear genetic background and completed genome sequence have become very popular in biological research. Insulin and insulin-like peptides (ILPs) are a class of peptides having important physiological functions, including promotion of cell proliferation and differentiation, and body growth and development. To date, many invertebrates have been identified with multiple ILP families, whose structures and functions have become increasingly clear to scientists. This review summarizes the ILPs identified in the model Lepidopteran insect Bombyx mori, in the aspects of structures and classification, functions and pathways. A brief discussion on the ILPs from several other model insects, including Drosophila melanogaster, Aedes aegypti, and Apis mellifera, was also included.