Annelid Endocrine Disruptors and a Survey of Invertebrate FMRFamide-Related Peptides

There is a growing body of literature describing the actionsof endocrine disruptors on annelids. These pollutants causedecreases in growth and reproductive output, delay sexual maturation,and inhibit the immune system in annelids. More studies areneeded to determine the mechanisms that underlie these responses.Most invertebrate endocrine disruptor research focuses on steroids.In recent years many new invertebrate peptide hormones includingthose related to the molluscan peptide FMRFamide have been identified.Since the storage of these peptides can be inhibited by steroidsduring insect metamorphosis, they may be affected by endocrinedisruptors. Therefore, it is worthwhile to give a brief overviewof this peptide family to those studying endocrine disruptionin invertebrates with the hope that they may begin to considerthese peptides in their future research. In 1977 Price and Greenbergisolated FMRFamide from the cerebral ganglia of the clam, Macrocallistanimbosa. Since then researchers have used bioassays and immunoassaysto identify a large number of FMRFamide-related peptides (FaRPs)from many invertebrate phyla. Even more peptides are predictedby the FaRP genes that have been sequenced. FaRPs have a varietyof functions and act as neurotransmitters, neuromodulators,or neurohormones. Each function is species and tissue specific.Most FaRP receptors are linked to a second messenger system.However, at least one is a ligand gated sodium channel. On goingstudies are examining FaRPs from the molecular to organismallevel.