Forward Signaling Mediated by Ephrin-B3 Prevents Contralateral Corticospinal Axons from Recrossing the Spinal Cord Midline

To investigate Eph-ephrin bidirectional signaling, a series of mutations were generated in the ephrin-B3 locus. The absence of both forward and reverse signaling resulted in mice with mirror movements as typified by a hopping locomotion. The corticospinal tract was defective as axons failed to respect the midline boundary of the spinal cord and bilaterally innervated both contralateral and ipsilateral motor neuron populations. A second mutation that expresses a truncated ephrin-B3 protein lacking its cytoplasmic domain did not lead to hopping, indicating that reverse signaling is not required for corticospinal innervation. Ephrin-B3 is concentrated at the spinal cord midline, while one of its receptors, EphA4, is expressed in postnatal corticospinal neurons as their fibers pathfind down the contralateral spinal cord. Our data indicate ephrin-B3 functions as a midline-anchored repellent to stimulate forward signaling in EphA4-expressing axons.

[1]  Dejan Popovi´c,et al.  Control of Movements , 1999 .

[2]  B. Stanfield.  The development of the corticospinal projection , 1992, Progress in Neurobiology.

[3]  L. Harrison,et al.  Mirror movements in X-linked Kallmann's syndrome. I. A neurophysiological study. , 1997, Brain : a journal of neurology.

[4]  C. Goodman,et al.  Slit Is the Midline Repellent for the Robo Receptor in Drosophila , 1999, Cell.

[5]  X. M. Xu,et al.  Postnatal growth of corticospinal axons in the spinal cord of developing mice. , 1999, Brain research. Developmental brain research.

[6]  Qiling Xu,et al.  Eph receptors and ephrins restrict cell intermingling and communication , 1999, Nature.

[7]  Chad A. Cowan,et al.  EphB2 Guides Axons at the Midline and Is Necessary for Normal Vestibular Function , 2000, Neuron.

[8]  C. Vierck,et al.  Criteria for assessing recovery of function after spinal cord injury: Behavioral methods , 1990, Experimental Neurology.

[9]  S. P. Evseev,et al.  The Control of Movement , 1996 .

[10]  T. Pawson,et al.  Nuk Controls Pathfinding of Commissural Axons in the Mammalian Central Nervous System , 1996, Cell.

[11]  S. Schneider-Maunoury,et al.  Targeting of the EphA4 tyrosine kinase receptor affects dorsal/ventral pathfinding of limb motor axons. , 2000, Development.

[12]  Karl J. Friston,et al.  Kallmann’s syndrome , 1999, Neurology.

[13]  F. Regli,et al.  Hereditary mirror movements. , 1967, Archives of neurology.

[14]  E. Jones,et al.  Growth and target finding by axons of the corticospinal tract in prenatal and postnatal rats , 1982, Neuroscience.

[15]  M E Blaw,et al.  On mirror movements , 1984, Annals of neurology.

[16]  J. Flanagan,et al.  Ephrin-B3, a ligand for the receptor EphB3, expressed at the midline of the developing neural tube , 1998, Oncogene.

[17]  G. Martin,et al.  An Fgf8 mutant allelic series generated by Cre- and Flp-mediated recombination , 1998, Nature Genetics.

[18]  A. Flenniken,et al.  Elk-L3, a novel transmembrane ligand for the Eph family of receptor tyrosine kinases, expressed in embryonic floor plate, roof plate and hindbrain segments. , 1996, Oncogene.

[19]  S. Robbins,et al.  Ephrin‐A5 modulates cell adhesion and morphology in an integrin‐dependent manner , 2000, The EMBO journal.

[20]  M. Barbacid,et al.  Ephrins and their Eph receptors: multitalented directors of embryonic development , 1999, The EMBO journal.

[21]  G. Schott,et al.  Congenital mirror movements. , 1981, Journal of neurology, neurosurgery, and psychiatry.

[22]  R. Young,et al.  Movement disorders in neurology and neuropsychiatry , 1992 .

[23]  R. Dolan,et al.  Mirror movements in X-linked Kallmann's syndrome. II. A PET study. , 1997, Brain : a journal of neurology.

[24]  J. Roder,et al.  Derivation of completely cell culture-derived mice from early-passage embryonic stem cells. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[25]  C. Goodman,et al.  Slit Proteins Bind Robo Receptors and Have an Evolutionarily Conserved Role in Repulsive Axon Guidance , 1999, Cell.

[26]  T Pawson,et al.  Ligands for EPH-related receptor tyrosine kinases that require membrane attachment or clustering for activity. , 1994, Science.

[27]  T. Terashima.  Anatomy, development and lesion-induced plasticity of rodent corticospinal tract , 1995, Neuroscience Research.

[28]  D. Wilkinson,et al.  Control of cell behaviour by signalling through Eph receptors and ephrins , 2000, Current Opinion in Neurobiology.

[29]  Z. Kaprielian,et al.  Complementary expression of transmembrane ephrins and their receptors in the mouse spinal cord: a possible role in constraining the orientation of longitudinally projecting axons. , 2000, Development.

[30]  K. Kalil,et al.  Development of specificity in corticospinal connections by axon collaterals branching selectively into appropriate spinal targets , 1994, The Journal of comparative neurology.

[31]  O. Kiehn,et al.  Distribution of Central Pattern Generators for Rhythmic Motor Outputs in the Spinal Cord of Limbed Vertebrates a , 1998, Annals of the New York Academy of Sciences.

[32]  D. Armstrong.  Supraspinal contributions to the initiation and control of locomotion in the cat , 1986, Progress in Neurobiology.

[33]  Marc Tessier-Lavigne,et al.  Roundabout Controls Axon Crossing of the CNS Midline and Defines a Novel Subfamily of Evolutionarily Conserved Guidance Receptors , 1998, Cell.

[34]  T. Pawson,et al.  Bidirectional signalling through the EPH-family receptor Nuk and its transmembrane ligands , 1996, Nature.

[35]  Philippe Soriano,et al.  Compartmentalized signaling by GPI-anchored ephrin-A5 requires the Fyn tyrosine kinase to regulate cellular adhesion. , 1999, Genes & development.

[36]  R. Bronson,et al.  Neonatal lethality and lymphopenia in mice with a homozygous disruption of the c-abl proto-oncogene , 1991, Cell.

[37]  E. Pasquale,et al.  Tyrosine Phosphorylation of Transmembrane Ligands for Eph Receptors , 1997, Science.

[38]  S Grillner,et al.  Central pattern generators for locomotion, with special reference to vertebrates. , 1985, Annual review of neuroscience.

[39]  S. Schneider-Maunoury,et al.  Expression pattern of a Krox‐20/Cre knock‐in allele in the developing hindbrain, bones, and peripheral nervous system , 2000, Genesis.

[40]  R. Guillery,et al.  Errors in corticospinal axon guidance in mice lacking the neural cell adhesion molecule L1 , 1998, Current Biology.

[41]  E. Marder,et al.  Principles of rhythmic motor pattern generation. , 1996, Physiological reviews.

[42]  J. Rossant,et al.  A novel regulatory region is required for trophoblast-specific transcription in transgenic mice. , 1995, Developmental biology.

[43]  T. Pawson,et al.  Immunolocalization of the Nuk receptor tyrosine kinase suggests roles in segmental patterning of the brain and axonogenesis. , 1994, Oncogene.

[44]  T. Bliss,et al.  Long-term potentiation in mice lacking the neural cell adhesion molecule L1 , 2000, Current Biology.

[45]  G Paxinos,et al.  EphA4 (Sek1) receptor tyrosine kinase is required for the development of the corticospinal tract. , 1998, Proceedings of the National Academy of Sciences of the United States of America.

[46]  S. Harel,et al.  [Hereditary mirror movements]. , 1982, Harefuah.

[47]  D. Wilkinson,et al.  In vivo cell sorting in complementary segmental domains mediated by Eph receptors and ephrins , 1999, Nature.

[48]  Chad A. Cowan,et al.  Kinase independent function of EphB receptors in retinal axon pathfinding to the optic disc from dorsal but not ventral retina. , 2000, Development.

[49]  B. Kolb,et al.  The Cerebral cortex of the rat , 1990 .

[50]  S. Dymecki.  Flp recombinase promotes site-specific DNA recombination in embryonic stem cells and transgenic mice. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[51]  J G Flanagan,et al.  The ephrins and Eph receptors in neural development. , 1998, Annual review of neuroscience.

[52]  G. Holstege.  The Basic, Somatic, And Emotional Components Of The Motor System In Mammals. , 1995 .

[53]  D. Buxton,et al.  Origins and collateralization of corticospinal, corticopontine, corticorubral and corticostriatal tracts: a multiple retrograde fluorescent tracing study , 1992, Brain Research.

[54]  G. Paxinos.  The Rat nervous system , 1985 .

[55]  P. Balbi,et al.  Patterns of motor control reorganization in a patient with mirror movements , 2000, Clinical Neurophysiology.

[56]  William A. Harris,et al.  Ephrin-B Regulates the Ipsilateral Routing of Retinal Axons at the Optic Chiasm , 2000, Neuron.

[57]  Cori Bargmann,et al.  Genes required for axon pathfinding and extension in the C. elegans nerve ring. , 1999, Development.

[58]  J. Barthe,et al.  Serotonin‐induced activation of the network for locomotion in adult spinal rats , 1999, Journal of neuroscience research.

[59]  R. S. Waters,et al.  Organization of the Mouse Motor Cortex Studied by Retrograde Tracing and Intracortical Microstimulation (ICMS) Mapping , 1991, Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques.

[60]  M. Romero,et al.  Visualization of Axonally Transported Horseradish Peroxidase Using Enhanced Immunocytochemical Detection: A Direct Comparison with the Tetramethylbenzidine Method , 1999, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.