title: Plexin a-semaphorin-1a reverse signaling regulates photoreceptor axon guidance in Drosophila.
abstract: While it is well established that Semaphorin family proteins function as axon guidance ligands in invertebrates and vertebrates, several recent studies indicate that the Drosophila Semaphorin-1a (Sema1a), a transmembrane Semaphorin, can also function as a receptor during neural development. The regulator of Sema1a reverse signaling, however, remains unknown. In this study, we show that like Sema1a, the well known Semaphorin receptor Plexin A (PlexA), is required for the proper guidance of photoreceptor (R cell) axons in the Drosophila visual system. Loss of PlexA, like loss of semala, disrupted the association of R-cell growth cones in the optic lobe. Conversely, overexpression of PlexA, like overexpression of sema1a, induced the hyperfasciculation of R-cell axons. Unlike Sema1a, however, the cytoplasmic domain of PlexA is dispensable. Epistasis analysis suggests that PlexA functions upstream of semala. And PlexA and sema1a interact genetically with Rho1. We propose that PlexA regulates Semala reverse signaling in the Drosophila visual system.
authors.affiliation: McGill Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada.
authors.forename: Li
authors.initials: L
authors.lastname: Yu
authors.forename: Yating
authors.initials: Y
authors.lastname: Zhou
authors.forename: Songting
authors.initials: S
authors.lastname: Cheng
authors.forename: Yong
authors.initials: Y
authors.lastname: Rao
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001369:Axons / Q000502:physiology*; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004625:Embryo, Nonmammalian; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology; D049452:Green Fluorescent Proteins / Q000235:genetics; D020439:Growth Cones / Q000502:physiology; D009154:Mutation / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009899:Optic Lobe, Nonmammalian / Q000166:cytology / Q000196:embryology / Q000502:physiology; D017956:Photoreceptor Cells, Invertebrate / Q000166:cytology*; D034622:RNA Interference / Q000502:physiology; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D039961:Semaphorins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology
chemical_list: D029721:Drosophila Proteins; D009419:Nerve Tissue Proteins; D011956:Receptors, Cell Surface; D039961:Semaphorins; C116483:plexA protein, Drosophila; C477531:semaphorin 1a, Drosophila; D049452:Green Fluorescent Proteins
references.citation: J Cell Sci. 2003 Jul 15;116(Pt 14):2823-32
references.pmid: 12808016
references.citation: J Neurosci. 2004 Jul 28;24(30):6639-49
references.pmid: 15282266
references.citation: Nat Neurosci. 1999 Sep;2(9):798-803
references.pmid: 10461218
references.citation: Neuron. 1998 Feb;20(2):207-20
references.pmid: 9491983
references.citation: Nat Neurosci. 2002 Dec;5(12):1294-301
references.pmid: 12436113
references.citation: Neuron. 2007 Jan 18;53(2):185-200
references.pmid: 17224402
references.citation: Trends Cell Biol. 2000 Sep;10(9):377-83
references.pmid: 10932095
references.citation: Cell. 1998 Dec 23;95(7):903-16
references.pmid: 9875845
references.citation: Cell. 2002 Jun 28;109(7):887-900
references.pmid: 12110185
references.citation: Science. 1996 Nov 15;274(5290):1123-33
references.pmid: 8895455
references.citation: Nature. 2000 Apr 6;404(6778):567-73
references.pmid: 10766232
references.citation: Biochem Biophys Res Commun. 2001 Jan 12;280(1):237-43
references.pmid: 11162505
references.citation: Mol Cell Neurosci. 1997;9(5-6):409-19
references.pmid: 9361278
references.citation: J Biol Chem. 2000 Dec 15;275(50):39647-53
references.pmid: 10993894
references.citation: J Biol Chem. 2001 Mar 23;276(12):9174-81
references.pmid: 11134026
references.citation: J Neurosci. 2006 Apr 12;26(15):3999-4003
references.pmid: 16611816
references.citation: Curr Opin Neurobiol. 2003 Feb;13(1):90-5
references.pmid: 12593986
references.citation: Development. 2005 Mar;132(6):1387-400
references.pmid: 15716342
references.citation: J Neurochem. 2001 Aug;78(3):482-9
references.pmid: 11483650
references.citation: Neuron. 1999 Nov;24(3):595-605
references.pmid: 10595512
references.citation: Curr Opin Neurobiol. 2003 Feb;13(1):79-89
references.pmid: 12593985
references.citation: Neuron. 2001 Oct 11;32(1):53-62
references.pmid: 11604138
references.citation: Neuron. 2002 Aug 29;35(5):827-41
references.pmid: 12372279
references.citation: Science. 2004 Feb 20;303(5661):1204-7
references.pmid: 14976319
references.citation: Trends Biochem Sci. 2008 Apr;33(4):161-70
references.pmid: 18374575
references.citation: Dev Biol. 1987 Sep;123(1):264-75
references.pmid: 17985474
references.citation: Nat Cell Biol. 2004 Dec;6(12):1204-11
references.pmid: 15543137
references.citation: Neuron. 2000 Aug;27(2):237-49
references.pmid: 10985345
references.citation: Curr Opin Neurobiol. 1998 Oct;8(5):587-92
references.pmid: 9811625
references.citation: Dev Dyn. 2005 Jan;232(1):1-10
references.pmid: 15580616
references.citation: Neuron. 2004 Dec 16;44(6):961-75
references.pmid: 15603739
references.citation: Cell. 2007 Jan 26;128(2):399-410
references.pmid: 17254975
references.citation: Neuron Glia Biol. 2008 Aug;4(3):211-21
references.pmid: 19785921