Meeting Abstract

P2.128  Thursday, Jan. 5  The identification of a FMRFamide –related peptide in the earthworm, Lumbricus rubellus MCCOMMAS, Steven A*; BAUER, Cassandra L; KERSTEIN, Kristopher W; MCCULLOUGH, Kyle A; KRAJNIAK, Kevin G; Southern Illinois University Edwardsville; Southern Illinois University Edwardsville; Southern Illinois University Edwardsville; Southern Illinois University Edwardsville; Southern Illinois University Edwardsville smccomm@siue.edu

FMRFamide is a neuropeptide that was first isolated from the cerebral ganglia of a bivalve mollusc. Since then many peptides with a sequence similar to FMRFamide have been isolated from many different invertebrate animals. In the phylum Annelida FMRFamide and other FMRFamide-related peptides (FaRPs) have been found in polychaetes and leeches. However so far no one has identified a FaRP from an earthworm. Many animal genomes have been sequenced and placed in public databases, including that of the earthworm, Lumbricus rubellus. Therefore we decided to examine whether any of the expressed sequence tags (ESTs) in Lumbribase, the L. rubellus database, contained any peptide sequences related to FMRFamide. Using the BLASTx program for translated nucleotide sequences we found an EST from the late cocoon stage that contained multiple copies of a sequence which, if cleaved at the basic residues and amidated would yield the peptide APKQYVRFamide. This peptide is similar in structure to two other predicted annelid peptides, PAKHYVRFamide from a leech and AGAYVRFamide from a polychaete. These three peptide sequences contain a tetrapeptide core of YVRFamide. We have already shown that FMRFamide modulates the motility of the earthworm digestive tract and body wall and are now examining how the tyrosine (Y) and valine (V) found in the YVRFamides affect these bioassays.