title: Peptidergic modulation of male sexual behavior in Lymnaea stagnalis: structural and functional characterization of -FVamide neuropeptides.
abstract: In the simultaneous hermaphrodite snail Lymnaea stagnalis, copulation as a male is controlled by neurons that send axons to the male copulatory organs via a single penis nerve. Using direct mass spectrometry of a penis nerve sample, we show that one of the molecular ions has a mass corresponding to GAPRFVamide, previously identified from the buccal ganglia, and named Lymnaea inhibitory peptide (LIP). The identity of this peptide is confirmed by partial peptide purification from the penis nerve, followed by post source decay mass spectrometry. We cloned the LIP-encoding cDNA, which predicts a prohormone that gives rise to five copies of LIP (now re-named LIP A), two other -FVamide peptides (LIPs B and C), and five structurally unrelated peptides. The LIP gene is expressed in neurons of the right cerebral ventral lobe that send their axons into the penis nerve. We show that the LIP A peptide is present in these neurons and in the penis nerve, and confirmed the presence of LIP B and C in the penis nerve by post source decay mass spectrometry. Finally, we demonstrate that LIP A, B and C inhibit the contractions of the penis retractor muscle, thereby implicating their role in male copulation behavior.
authors: Department of Molecular and Cellular Neurobiology, Faculty of Earth and Life Sciences, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands. absmit@bio.vu.nl
authors: A B
authors: AB
authors: Smit
authors: R E
authors: RE
authors: van Kesteren
authors: S
authors: S
authors: Spijker
authors: J
authors: J
authors: Van Minnen
authors: F A
authors: FA
authors: van Golen
authors: C R
authors: CR
authors: Jiménez
authors: K W
authors: KW
authors: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002490:Central Nervous System / Q000378:metabolism; D003001:Cloning, Molecular; D007447:Invertebrate Hormones / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D008195:Lymnaea / Q000378:metabolism / Q000502:physiology*; D008297:Male; D008969:Molecular Sequence Data; D009433:Neural Inhibition / Q000502:physiology; D009479:Neuropeptides / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D010413:Penis / Q000294:innervation; D010525:Peripheral Nerves / Q000737:chemistry / Q000378:metabolism; D012726:Sexual Behavior, Animal / Q000502:physiology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013329:Structure-Activity Relationship
chemical_list: D007447:Invertebrate Hormones; D009479:Neuropeptides