DEVELOPMENTAL EXPRESSION OF HETEROTRIMERIC G-PROTEINS IN THE NERVOUS-SYSTEM OF MANDUCA-SEXTA

The heterotrimeric G proteins are a conserved family of guanyl nucleot ide-binding proteins that appear in all eukaryotic cells but whose dev elopmental functions are largely unknown, We have examined the develop mental expression of representative G proteins in the developing nervo us system of the moth Manduca sexta, Using affinity-purified antisera against different G(alpha) subunits, we found that each of the G prote ins exhibited distinctive patterns of expression within the developing central nervous system (CNS), and that these patterns underwent progr essive phases of spatial and temporal regulation that corresponded to specific aspects of neuronal differentiation. Several of the G protein s examined (including Gs(alpha) and Go(alpha)) were expressed in an ap parently ubiquitous manner in all neurons, but other proteins (includi ng Gi(alpha)) were ultimately confined to a more restricted subset of cells in the mature CNS. Although most of the G proteins examined coul d be detected within the central ganglia, only Go(alpha)-related prote ins were seen in the developing peripheral nerves; manipulations of G protein activity in cultured embryos suggested that this class of G pr otein may contribute to the regulation of neuronal motility during axo nal outgrowth. Go(alpha)-related proteins were also localized to the d eveloping axons and terminals of the developing adult limb during meta morphosis, These intracellular signaling molecules may, therefore, pla y similar developmental roles in both the embryonic and postembryonic nervous system. (C) 1995 John Wiley & Sons, Inc.