title: Leucine-rich repeat transmembrane proteins instruct discrete dendrite targeting in an olfactory map.
abstract: Olfactory systems utilize discrete neural pathways to process and integrate odorant information. In Drosophila, axons of first-order olfactory receptor neurons (ORNs) and dendrites of second-order projection neurons (PNs) form class-specific synaptic connections at approximately 50 glomeruli. The mechanisms underlying PN dendrite targeting to distinct glomeruli in a three-dimensional discrete neural map are unclear. We found that the leucine-rich repeat (LRR) transmembrane protein Capricious (Caps) was differentially expressed in different classes of PNs. Loss-of-function and gain-of-function studies indicated that Caps instructs the segregation of Caps-positive and Caps-negative PN dendrites to discrete glomerular targets. Moreover, Caps-mediated PN dendrite targeting was independent of presynaptic ORNs and did not involve homophilic interactions. The closely related protein Tartan was partially redundant with Caps. These LRR proteins are probably part of a combinatorial cell-surface code that instructs discrete olfactory map formation.
authors.affiliation: Howard Hughes Medical Institute and Department of Biology, Stanford University, Stanford, California, USA.
authors.forename: Weizhe
authors.initials: W
authors.lastname: Hong
authors.forename: Haitao
authors.initials: H
authors.lastname: Zhu
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Potter
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Barsh
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Kurusu
authors.forename: Kai
authors.initials: K
authors.lastname: Zinn
authors.forename: Liqun
authors.initials: L
authors.lastname: Luo
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology; D003712:Dendrites / Q000502:physiology*; D004330:Drosophila / Q000196:embryology / Q000502:physiology*; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017952:Ganglia, Invertebrate / Q000166:cytology / Q000196:embryology / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D007930:Leucine; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016296:Mutagenesis / Q000502:physiology; D009833:Olfactory Pathways / Q000166:cytology / Q000196:embryology / Q000502:physiology; D018034:Olfactory Receptor Neurons / Q000502:physiology* / Q000648:ultrastructure; D010641:Phenotype; D017434:Protein Structure, Tertiary; D017661:Receptors, Presynaptic / Q000502:physiology
chemical_list: D029721:Drosophila Proteins; D008565:Membrane Proteins; D017661:Receptors, Presynaptic; C113006:caps protein, Drosophila; C084647:trn protein, Drosophila; D007930:Leucine