CHARACTERIZATION OF A CDNA CLONE ENCODING PEDAL PEPTIDE IN THE TERRESTRIAL SNAIL

WE report the isolation of a Helix lucorum cDNA clone encoding a precu rsor of neuropeptides that are closely related to Aplysia and Tritonia pedal peptides (Pep). The predicted propeptide contains 20 copies of the two variants of Helix Pep interspersed with Lys-Arg endopeptidase cleavage sites. Northern blot hybridization revealed multiple Pep-hybr idizing species in the Helix CNS RNA. The Pep gene was expressed by se veral identified serotonergic neurones in pedal and cerebral ganglia, groups of sensory neurones in procerebrum, peripheral neurones in olfa ctory bulb, mantle and foot, and group of neurones in pedal ganglia pr esumably involved in locomotion control. Pep mRNA was detected in seve ral neurones at the early stages of nervous system development.