Gene sequence and related structure of neuropeptides in invertebrates

Numerous neuropeptides were studied in different invertebrate species, but the presence of most of them was evaluated only by an immunocytochemical approach using antibodies against the vertebrate homologues. As a consequence, several authors referred to the presence of neuropeptide-like molecules. In view of the availability of numerous wholly sequenced invertebrate genomes, here we reviewed the data on the gene sequence and the related structure of four neuropeptides (corticotrophin-releasing hormone, tachykinins, bombesin and insulin) in invertebrates, analyzing their functions in comparison to what reported in vertebrates.