Abstract:  As a class of neuronal signal molecules, neuropeptides are secreted by the neurosecretory cells and play an important role during the communications of different cells. The specific receptor molecules, which are located on the cell surface, are responsible for the localization of neuropeptide molecules and the activation of corresponding intracellular messengers, and eventually trigger a series of cascade reactions. Neuropeptides also have crucial effects on the growth and development of insects, and regulate almost all life activities. As a model species of the Lepidoptera, the silkworm (Bombyx mori) is an important research model for insect development and physiology. Following the completion of the silkworm genome sequencing, more and more neuropeptides and their receptors in this moth have been identified. They were found to deeply influence lots of physiological activities, such as the growth and development, feeding and digestion, molting, diapause, reproduction and cocooning. In this article, we reviewed crucial neuropeptides in the silkworm and their regulation roles in feeding and digestion, molting and metamorphosis, reproduction and development, and other physiological processes. We also discussed the molecular mechanisms that neuropeptides activate the downstream signal transduction pathways, such as ERK and TOR, by binding to their specific receptors. It is expected to provide insights and references for the research of neuropeptides and their receptors in insects, so to advance the research of functional genes of the silkworm and promote the development of silk industry.  

Key words: Bombyx mori, neuropeptides, G protein coupled receptors, molecular mechanism, signal transduction