FMRFamide neuropeptides and acetylcholine synergistically inhibit egg-laying by C. elegans

Egg-laying behavior of the Caenorhabditis elegans hermaphrodite is regulated by G protein signaling pathways. Here we show that the egg laying–defective mutant egl-6(n592) carries an activating mutation in a G protein–coupled receptor that inhibits C. elegans egg-laying motor neurons in a Go-dependent manner. Ligands for EGL-6 are Phe-Met-Arg-Phe-NH2 (FMRFamide)-related peptides encoded by the genes flp-10 and flp-17. flp-10 is expressed in both neurons and non-neuronal cells. The major source of flp-17 peptides is a pair of presumptive sensory neurons, the BAG neurons. Genetic analysis of the egl-6 pathway revealed that the EGL-6 neuropeptide signaling pathway functions redundantly with acetylcholine to inhibit egg-laying. The retention of embryos in the uterus of the C. elegans hermaphrodite is therefore under the control of a presumptive sensory system and is inhibited by the convergence of signals from neuropeptides and the small-molecule neurotransmitter acetylcholine.

[1]  I. Putrenko,et al.  A Family of Acetylcholine-gated Chloride Channel Subunits in Caenorhabditis elegans* , 2005, Journal of Biological Chemistry.

[2]  J. Duerr,et al.  Identified neurons in C. elegans coexpress vesicular transporters for acetylcholine and monoamines. , 2001, American journal of physiology. Cell physiology.

[3]  J. Kaplan,et al.  The EGL-3 Proprotein Convertase Regulates Mechanosensory Responses of Caenorhabditis elegans , 2001, The Journal of Neuroscience.

[4]  B. Kaang,et al.  Characterization of GAR‐2, a Novel G Protein‐Linked Acetylcholine Receptor from Caenorhabditis elegans , 2000, Journal of neurochemistry.

[5]  B. Kaang,et al.  Cloning and Expression of a G Protein‐Linked Acetylcholine Receptor from Caenorhabditis elegans , 1999, Journal of neurochemistry.

[6]  H. Horvitz,et al.  Egg-laying defective mutants of the nematode Caenorhabditis elegans. , 1983, Genetics.

[7]  H. Horvitz,et al.  Serotonin and octopamine in the nematode Caenorhabditis elegans. , 1982, Science.

[8]  A. Jose,et al.  A Specific Subset of Transient Receptor Potential Vanilloid-Type Channel Subunits in Caenorhabditis elegans Endocrine Cells Function as Mixed Heteromers to Promote Neurotransmitter Release , 2007, Genetics.

[9]  H. Horvitz,et al.  EAT-4, a Homolog of a Mammalian Sodium-Dependent Inorganic Phosphate Cotransporter, Is Necessary for Glutamatergic Neurotransmission in Caenorhabditis elegans , 1999, The Journal of Neuroscience.

[10]  Appendix 2 Neurotransmitter Assignments for Specific Neurons , 1997 .

[11]  R. Kerr,et al.  Serotonin and Go Modulate Functional States of Neurons and Muscles Controlling C. elegans Egg-Laying Behavior , 2003, Current Biology.

[12]  Kyuhyung Kim,et al.  Expression and regulation of an FMRFamide‐related neuropeptide gene family in Caenorhabditis elegans , 2004, The Journal of comparative neurology.

[13]  Robert J. Hobson,et al.  SER-7, a Caenorhabditis elegans 5-HT7-like Receptor, Is Essential for the 5-HT Stimulation of Pharyngeal Pumping and Egg Laying , 2006, Genetics.

[14]  S. Brenner,et al.  The structure of the nervous system of the nematode Caenorhabditis elegans. , 1986, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[15]  Jeremy Mendel,et al.  Participation of the protein Go in multiple aspects of behavior in C. elegans , 1995, Science.

[16]  A. Alfonso,et al.  The Caenorhabditis elegans unc-17 gene: a putative vesicular acetylcholine transporter. , 1993, Science.

[17]  W. Gish,et al.  Rapid gene mapping in Caenorhabditis elegans using a high density polymorphism map , 2001, Nature Genetics.

[18]  L. Schoofs,et al.  Identification in Drosophila melanogaster of the invertebrate G protein-coupled FMRFamide receptor , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[19]  E. Myers,et al.  Basic local alignment search tool. , 1990, Journal of molecular biology.

[20]  D. Weinshenker,et al.  Genetic and pharmacological analysis of neurotransmitters controlling egg laying in C. elegans , 1995, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[21]  Peter Dalgaard,et al.  R Development Core Team (2010): R: A language and environment for statistical computing , 2010 .

[22]  Randle W. Ware,et al.  The nerve ring of the nematode Caenorhabditis elegans: Sensory input and motor output , 1975 .

[23]  S. Ward,et al.  Electron microscopical reconstruction of the anterior sensory anatomy of the nematode caenorhabditis elegans , 1975, The Journal of comparative neurology.

[24]  Paul W. Sternberg,et al.  Acute carbon dioxide avoidance in Caenorhabditis elegans , 2008, Proceedings of the National Academy of Sciences.

[25]  H. Horvitz,et al.  The Caenorhabditis elegans Gene unc-25Encodes Glutamic Acid Decarboxylase and Is Required for Synaptic Transmission But Not Synaptic Development , 1999, The Journal of Neuroscience.

[26]  William R. Schafer,et al.  Control of Alternative Behavioral States by Serotonin in Caenorhabditis elegans , 1998, Neuron.

[27]  Gary Ruvkun,et al.  The unc-86 gene product couples cell lineage and cell identity in C. elegans , 1990, Cell.

[28]  U. Gether.  Uncovering molecular mechanisms involved in activation of G protein-coupled receptors. , 2000, Endocrine reviews.

[29]  C. Li,et al.  The ever-expanding neuropeptide gene families in the nematode Caenorhabditis elegans , 2005, Parasitology.

[30]  G. Ruvkun,et al.  Food and metabolic signalling defects in a Caenorhabditis elegans serotonin-synthesis mutant , 2000, Nature.

[31]  J. Rand.  Genetic analysis of the cha-1-unc-17 gene complex in Caenorhabditis. , 1989, Genetics.

[32]  L. Carnell,et al.  The G-Protein-Coupled Serotonin Receptor SER-1 Regulates Egg Laying and Male Mating Behaviors in Caenorhabditis elegans , 2005, The Journal of Neuroscience.

[33]  L. Avery,et al.  Mutations in a C. elegans Gqalpha gene disrupt movement, egg laying, and viability. , 1996, Neuron.

[34]  J. Kaplan,et al.  Serotonin Inhibition of Synaptic Transmission Gαo Decreases the Abundance of UNC-13 at Release Sites , 1999, Neuron.

[35]  L. Ségalat,et al.  Modulation of serotonin-controlled behaviors by Go in Caenorhabditis elegans , 1995, Science.

[36]  J. Tytgat,et al.  Subunit stoichiometry of a mammalian K+ channel determined by construction of multimeric cDNAs , 1992, Neuron.

[37]  J. Moresco,et al.  Activation of EGL-47, a Gαo-Coupled Receptor, Inhibits Function of Hermaphrodite-Specific Motor Neurons to Regulate Caenorhabditis elegans Egg-Laying Behavior , 2004, The Journal of Neuroscience.

[38]  J. Kaplan,et al.  Facilitation of Synaptic Transmission by EGL-30 Gqα and EGL-8 PLCβ DAG Binding to UNC-13 Is Required to Stimulate Acetylcholine Release , 1999, Neuron.

[39]  Michael R Koelle,et al.  Genetic and Cellular Basis for Acetylcholine Inhibition of Caenorhabditis elegans Egg-Laying Behavior , 2003, The Journal of Neuroscience.

[40]  J. Sulston,et al.  Dopaminergic neurons in the nematode Caenorhabditis elegans , 1975, The Journal of comparative neurology.

[41]  J. Culotti,et al.  A second class of acetylcholinesterase-deficient mutants of the nematode Caenorhabditis elegans. , 1981, Genetics.

[42]  J. Kaplan,et al.  Facilitation of synaptic transmission by EGL-30 Gqalpha and EGL-8 PLCbeta: DAG binding to UNC-13 is required to stimulate acetylcholine release. , 1999, Neuron.

[43]  Mark J Alkema,et al.  Tyramine Functions Independently of Octopamine in the Caenorhabditis elegans Nervous System , 2005, Neuron.

[44]  K. Miller,et al.  Goalpha and diacylglycerol kinase negatively regulate the Gqalpha pathway in C. elegans. , 1999, Neuron.

[45]  L. Avery,et al.  Mutations in a C. elegans Gqα Gene Disrupt Movement, Egg Laying, and Viability , 1996, Neuron.

[46]  Cori Bargmann,et al.  Laser killing of cells in Caenorhabditis elegans. , 1995, Methods in cell biology.

[47]  Mario de Bono,et al.  Inhibition of Caenorhabditis elegans social feeding by FMRFamide-related peptide activation of NPR-1 , 2003, Nature Neuroscience.

[48]  J. Kaplan,et al.  The EGL-21 Carboxypeptidase E Facilitates Acetylcholine Release at Caenorhabditis elegans Neuromuscular Junctions , 2003, The Journal of Neuroscience.

[49]  C. Grimmelikhuijzen,et al.  Molecular cloning and functional expression of the first insect FMRFamide receptor , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[50]  J. Hwang,et al.  Cloning and functional characterization of a Caenorhabditis elegans muscarinic acetylcholine receptor. , 1999, Receptors & channels.

[51]  A. Alfonso,et al.  Cloning and characterization of the choline acetyltransferase structural gene (cha-1) from C. elegans , 1994, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[52]  A. Hart,et al.  Identification of neuropeptide-like protein gene families in Caenorhabditis elegans and other species , 2001, Proceedings of the National Academy of Sciences of the United States of America.