title: Requirement for commissureless2 function during dipteran insect nerve cord development.
abstract: BACKGROUND
  In Drosophila melanogaster, commissureless (comm) function is required for proper nerve cord development. Although comm orthologs have not been identified outside of Drosophila species, some insects possess orthologs of Drosophila comm2, which may also regulate embryonic nerve cord development. Here, this hypothesis is explored through characterization of comm2 genes in two disease vector mosquitoes.
  
  
  RESULTS
  Culex quinquefasciatus (West Nile and lymphatic filiariasis vector) has three comm2 genes that are expressed in the developing nerve cord. Aedes aegypti (dengue and yellow fever vector) has a single comm2 gene that is expressed in commissural neurons projecting axons toward the midline. Loss of comm2 function in both A. aegypti and D. melanogaster was found to result in loss of commissure defects that phenocopy the frazzled (fra) loss of function phenotypes observed in both species. Loss of fra function in either insect was found to result in decreased comm2 transcript levels during nerve cord development.
  
  
  CONCLUSIONS
  The results of this investigation suggest that Fra down-regulates repulsion in precrossing commissural axons by regulating comm2 levels in both A. aegypti and D. melanogaster, both of which require Comm2 function for proper nerve cord development.
authors.affiliation: Eck Institute for Global Health and Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana.
authors.forename: Joseph
authors.initials: J
authors.lastname: Sarro
authors.forename: Emily
authors.initials: E
authors.lastname: Andrews
authors.forename: Longhua
authors.initials: L
authors.lastname: Sun
authors.forename: Susanta K
authors.initials: SK
authors.lastname: Behura
authors.forename: John C
authors.initials: JC
authors.lastname: Tan
authors.forename: Erliang
authors.initials: E
authors.lastname: Zeng
authors.forename: David W
authors.initials: DW
authors.lastname: Severson
authors.forename: Molly
authors.initials: M
authors.lastname: Duman-Scheel
mesh_terms: D000330:Aedes / Q000196:embryology / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D016000:Cluster Analysis; D003465:Culex / Q000196:embryology / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D055785:Gene Knockdown Techniques; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D046228:Microarray Analysis; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009420:Nervous System / Q000196:embryology* / Q000378:metabolism; D000075386:Netrin Receptors; D010802:Phylogeny; D034622:RNA Interference; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D029721:Drosophila Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D000075386:Netrin Receptors; D011956:Receptors, Cell Surface; C000589381:comm2 protein, Drosophila; C000617310:fra protein, Drosophila
keywords: Aedes aegypti; Culex quinquefasciatus; Drosophila melanogaster; commissureless; development; frazzled; mosquito; nervous system
references.citation: Cold Spring Harb Protoc. 2010 Oct 01;2010(10):pdb.prot5511
references.pmid: 20889708
references.citation: Neural Dev. 2012 Nov 09;7:36
references.pmid: 23140504
references.citation: Nucleic Acids Res. 2009 Jan;37(Database issue):D583-7
references.pmid: 19028744
references.citation: Fly (Austin). 2008 Nov-Dec;2(6):323-5
references.pmid: 19029797
references.citation: Genetics. 2005 Oct;171(2):571-81
references.pmid: 15972463
references.citation: Cold Spring Harb Protoc. 2010 Oct 01;2010(10):pdb.prot5509
references.pmid: 20889706
references.citation: Dev Genes Evol. 2003 Oct;213(10):500-4
references.pmid: 12928898
references.citation: Cell. 1996 Oct 18;87(2):197-204
references.pmid: 8861904
references.citation: PLoS One. 2011;6(6):e21694
references.pmid: 21738767
references.citation: Nat Neurosci. 2005 Feb;8(2):156-63
references.pmid: 15657595
references.citation: Development. 1999 Jun;126(11):2327-34
references.pmid: 10225992
references.citation: Science. 2001 Mar 9;291(5510):1928-38
references.pmid: 11239147
references.citation: Cold Spring Harb Protoc. 2010 Oct 01;2010(10):pdb.prot5510
references.pmid: 20889707
references.citation: Annu Rev Cell Dev Biol. 2006;22:651-75
references.pmid: 17029581
references.citation: Science. 2009 May 15;324(5929):944-7
references.pmid: 19325078
references.citation: Genet Res. 1992 Dec;60(3):209-20
references.pmid: 1286805
references.citation: Dev Biol. 2012 Mar 1;363(1):266-78
references.pmid: 22245052
references.citation: Evodevo. 2013 Mar 06;4(1):9
references.pmid: 23497573
references.citation: Science. 2007 Jun 22;316(5832):1718-23
references.pmid: 17510324
references.citation: Nucleic Acids Res. 2008 Jan;36(Database issue):D271-5
references.pmid: 17947323
references.citation: Science. 2010 Oct 1;330(6000):86-8
references.pmid: 20929810
references.citation: Nucleic Acids Res. 2003 Jul 1;31(13):3497-500
references.pmid: 12824352
references.citation: Mol Biol Evol. 1987 Jul;4(4):406-25
references.pmid: 3447015
references.citation: PLoS One. 2011;6(7):e21504
references.pmid: 21754989
references.citation: Genetics. 2011 Jul;188(3):731-43
references.pmid: 21515576
references.citation: Cold Spring Harb Protoc. 2010 Oct 01;2010(10):pdb.prot5507
references.pmid: 20889704
references.citation: Development. 1998 Oct;125(19):3853-63
references.pmid: 9729493
references.citation: Neuron. 1996 Mar;16(3):501-14
references.pmid: 8785048
references.citation: Nucleic Acids Res. 2009 Jan;37(Database issue):D555-9
references.pmid: 18948289
references.citation: Dev Neurobiol. 2010 Jun;70(7):473-84
references.pmid: 20162636
references.citation: Genesis. 2001 Sep;31(1):17-29
references.pmid: 11668674
references.citation: BMC Genomics. 2009 Jan 14;10:22
references.pmid: 19144180
references.citation: Cell. 2002 Aug 23;110(4):415-27
references.pmid: 12202032
references.citation: Cell. 1999 Mar 19;96(6):785-94
references.pmid: 10102267
references.citation: Science. 2002 Dec 6;298(5600):1959-64
references.pmid: 12471249
references.citation: Mol Biol Evol. 2007 Aug;24(8):1596-9
references.pmid: 17488738
references.citation: Neuron. 1993 Mar;10(3):409-26
references.pmid: 8461134
references.citation: PLoS One. 2011 Jan 31;6(1):e16730
references.pmid: 21304954
references.citation: Genome Biol. 2012;13(3):R21
references.pmid: 22445104
references.citation: Cold Spring Harb Protoc. 2010 Oct 01;2010(10):pdb.prot5508
references.pmid: 20889705
references.citation: Methods Cell Biol. 1994;44:445-87
references.pmid: 7707967