History of the Study on Insect Peptide Hormones: From Experimental Morphological Study to Molecular Genetic Approach

Research in insect endocrinology, which began in the early twentieth century, made great progress during the last two decades of the twentieth century with the identification of a wide variety of insect hormones and neuropeptides. Moreover, since 2000, this research field has entered a new stage of development, supported by innovations in research techniques, such as genome sequencing, bioinformatics, genetic manipulation, and imaging. This chapter looks back at the history of the development of insect peptide hormone research, focusing on advances and innovations in research methods. However, it goes without saying that the excellent research ability and constant efforts of researchers are essential for the development of research. Thus, to emphasize the importance of consecutive efforts of individual researchers, we first review the history of a purification study of the prothoracicotropic hormone that extended to three decades.