21st Conference of European Comparative Endocrinologists edition:21 location:Bonn (Germany) date:26-30 August 2002
Neuropeptides form the most diverse category of extracellular messenger molecules in metazoan nervous systems. Bioactive peptide molecules are usually generated from biosynthetic precursors via enzymatic cleavage and modification pathways. Molecular diversity can thus be created at all different levels of the peptide synthesis scheme. Many peptides can be grouped into families, some of which are well conserved and have an ancient origin that precedes the divergence of important animal Phyla. In addition, many multiplication as well as diversification events have occurred during evolution. A few examples of peptide families, conserved during evolution, will be reviewed in more detail: tachykinin-, NPY/NPF-, insulin-related peptides and glycoprotein hormones. Since peptides exert their biological function via specific signal-transducing receptor proteins, their evolution is believed to be 'tuned' by the evolution of the corresponding receptor genes. The availability of novel gene and transcript sequence information is growing very rapidly as a result of molecular cloning experiments and of metazoan genome (C. elegans, D. melanogaster, H. sapiens) and EST (expressed sequence tags) sequencing projects. These genome projects will have an important impact on neurobiological research and already provide more insight into the evolution of genes coding for important components of neuronal and endocrine signalling processes, such as peptide precursors and receptor genes.