RRC ID 382
Author Yeo SY, Miyashita T, Fricke C, Little MH, Yamada T, Kuwada JY, Huh TL, Chien CB, Okamoto H.
Title Involvement of Islet-2 in the Slit signaling for axonal branching and defasciculation of the sensory neurons in embryonic zebrafish.
Journal Mech. Dev.
Abstract In Drosophila melanogaster, Slit acts as a repulsive cue for the growth cones of the commissural axons which express a receptor for Slit, Roundabout (Robo), thus preventing the commissural axons from crossing the midline multiple times. Experiments using explant culture have shown that vertebrate Slit homologues also act repulsively for growth cone navigation and neural migration, and promote branching and elongation of sensory axons. Here, we demonstrate that overexpression of Slit2 in vivo in transgenic zebrafish embryos severely affected the behavior of the commissural reticulospinal neurons (Mauthner neurons), promoted branching of the peripheral axons of the trigeminal sensory ganglion neurons, and induced defasciculation of the medial longitudinal fascicles. In addition, Slit2 overexpression caused defasciculation and deflection of the central axons of the trigeminal sensory ganglion neurons from the hindbrain entry point. The central projection was restored by either functional repression or mutation of Robo2, supporting its role as a receptor mediating the Slit signaling in vertebrate neurons. Furthermore, we demonstrated that Islet-2, a LIM/homeodomain-type transcription factor, is essential for Slit2 to induce axonal branching of the trigeminal sensory ganglion neurons, suggesting that factors functioning downstream of Islet-2 are essential for mediating the Slit signaling for promotion of axonal branching.
Volume 121(4)
Pages 315-24
Published 2004-4
DOI 10.1016/j.mod.2004.03.006
PII S0925477304000425
PMID 15110042
MeSH Animals Animals, Genetically Modified Axons / metabolism* Genes, Reporter Glycoproteins / genetics Glycoproteins / metabolism* Homeodomain Proteins / metabolism* LIM-Homeodomain Proteins Nerve Tissue Proteins / genetics Nerve Tissue Proteins / metabolism* Neurons, Afferent / metabolism* RNA, Messenger / metabolism Receptors, Immunologic / genetics Receptors, Immunologic / metabolism Recombinant Fusion Proteins Signal Transduction / physiology* Transcription Factors / metabolism* Trigeminal Ganglion / metabolism Zebrafish / embryology* Zebrafish / metabolism Zebrafish Proteins / metabolism*
IF 1.9
Times Cited 49
Zebrafish rw015a rw015b rw015e rw015d