Islet1 selectively promotes peripheral axon outgrowth in Rohon-Beard primary sensory neurons.
We isolated a novel zebrafish mutant, lullaby (llb), and showed that the llb locus encodes the zebrafish orthologue of isl1. Rohon-Beard (RB) primary sensory neurons are multipolar neurons that extend their central axons longitudinally within the spinal cord and also extend their peripheral axons under the skin. In llb embryos, the outgrowth of the peripheral axons of RB neurons was selectively impaired, which correlated with down-regulation of the expression of dihydropyrimidinase-like 3 (dpysl3, also known as collapsin response mediator protein 4, crmp4). Antisense morpholino oligonucleotide (AMO)-mediated knockdown of dpysl3 inhibited the outgrowth of the peripheral axons of RB neurons, and semaphorin 3d (sema3d) AMO enhanced this effect. These data indicate that Dpysl3 is cooperating with Sema3d in the peripheral axon outgrowth, and Isl1 is required for the selective outgrowth of the peripheral axons of RB neurons by maintaining the expression of dpysl3.
Laboratory for Developmental Gene Regulation, RIKEN Brain Science Institute (BSI), Saitama, Japan. hideomi@aoni.waseda.jp
Hideomi
H
Tanaka
Yasuhiro
Y
Nojima
Wataru
W
Shoji
Miki
M
Sato
Ryoko
R
Nakayama
Toshio
T
Ohshima
Hitoshi
H
Okamoto
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001369:Axons / Q000378:metabolism / Q000502:physiology*; D001483:Base Sequence; D004625:Embryo, Nonmammalian; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D056426:Genetic Loci; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D060850:LIM-Homeodomain Proteins; D008954:Models, Biological; D008969:Molecular Sequence Data; D009046:Motor Neurons / Q000378:metabolism / Q000502:physiology; D009154:Mutation / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D011984:Sensory Receptor Cells / Q000378:metabolism / Q000502:physiology*; D017385:Sequence Homology; D013127:Spinal Nerves / Q000002:abnormalities / Q000196:embryology / Q000378:metabolism; D014157:Transcription Factors; D015027:Zebrafish / Q000196:embryology / Q000235:genetics / Q000502:physiology; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
C576247:Dpysl3 protein, zebrafish; D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D009419:Nerve Tissue Proteins; D014157:Transcription Factors; D029961:Zebrafish Proteins; C063843:insulin gene enhancer binding protein Isl-1