title: Lateral signaling mediated by axon contact and calcium entry regulates asymmetric odorant receptor expression in C. elegans.
abstract: C. elegans detects several odorants with the bilaterally symmetric pair of AWC olfactory neurons. A stochastic, coordinated decision ensures that the candidate odorant receptor gene str-2 is expressed in only one AWC neuron in each animal--either the left or the right neuron, but never both. An interaction between the two AWC neurons generates asymmetric str-2 expression in a process that requires normal axon guidance and probably AWC axon contact. This interaction induces str-2 expression by reducing calcium signaling through a voltage-dependent Ca2+ channel and the CaM kinase II UNC-43. CaMKII activity acts as a switch in the initial decision to express str-2; thus, calcium signals can define distinct cell types during neuronal development. A cGMP signaling pathway that is used in olfaction maintains str-2 expression after the initial decision has been made.
authors.affiliation: Howard Hughes Medical Institute, Department of Anatomy, The University of California, San Francisco 94143-0452, USA.
authors.forename: E R
authors.initials: ER
authors.lastname: Troemel
authors.forename: A
authors.initials: A
authors.lastname: Sagasti
authors.forename: C I
authors.initials: CI
authors.lastname: Bargmann
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001369:Axons / Q000378:metabolism* / Q000502:physiology; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D018507:Gene Expression Regulation, Developmental; D008969:Molecular Sequence Data; D009154:Mutation; D009474:Neurons / Q000378:metabolism; D018035:Receptors, Odorant / Q000096:biosynthesis* / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics
chemical_list: D018035:Receptors, Odorant; D011993:Recombinant Fusion Proteins; C514941:Str-2 protein, C elegans; D002118:Calcium