TY - JOUR
T1 - Requirement for the homeobox gene Hb9 in the consolidation of motor neuron identity
AU - Arber, Silvia
AU - Han, Barbara
AU - Mendelsohn, Monica
AU - Smith, Michael
AU - Jessell, Thomas M.
AU - Sockanathan, Shanthini
N1 - Funding Information:
We thank S. Morton and C. William for antibodies, S. Kaplan for expert technical assistance, C. Stewart for W9.5 cells, and J. Kehrl for communication of unpublished results. We are grateful to S. Pfaff for ongoing discussions, for providing an anti-C-terminal HB9 antiserum, and for initial studies that contributed to the characterization of the 9 kb regulatory region of Hb9. K. MacArthur and I. Schieren provided expert help in preparing the manuscript and figures, and J. Briscoe, P. Caroni, and K. Lee provided helpful comments on the manuscript. S. S. and T. M. J. are supported by grants from the National Institutes of Health, and S. A. is supported by a grant from the Swiss National Science Foundation and a Human Frontiers Scientific Program Fellowship. T. M. J. is an Investigator of the Howard Hughes Medical Institute.
PY - 1999/8
Y1 - 1999/8
N2 - The homeobox gene Hb9, like its close relative MNR2, is expressed selectively by motor neurons (MNs) in the developing vertebrate CNS. In embryonic chick spinal cord, the ectopic expression of MNR2 or Hb9 is sufficient to trigger MN differentiation and to repress the differentiation of an adjacent population of V2 interneurons. Here, we provide genetic evidence that Hb9 has an essential role in MN differentiation. In mice lacking Hb9 function, MNs are generated on schedule and in normal numbers but transiently acquire molecular features of V2 interneurons. The aberrant specification of MN identity is associated with defects in the migration of MNs, the emergence of the subtype identities of MNs, and the projection of motor axons. These findings show that HB9 has an essential function in consolidating the identity of postmitotic MNs.
AB - The homeobox gene Hb9, like its close relative MNR2, is expressed selectively by motor neurons (MNs) in the developing vertebrate CNS. In embryonic chick spinal cord, the ectopic expression of MNR2 or Hb9 is sufficient to trigger MN differentiation and to repress the differentiation of an adjacent population of V2 interneurons. Here, we provide genetic evidence that Hb9 has an essential role in MN differentiation. In mice lacking Hb9 function, MNs are generated on schedule and in normal numbers but transiently acquire molecular features of V2 interneurons. The aberrant specification of MN identity is associated with defects in the migration of MNs, the emergence of the subtype identities of MNs, and the projection of motor axons. These findings show that HB9 has an essential function in consolidating the identity of postmitotic MNs.
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U2 - 10.1016/S0896-6273(01)80026-X
DO - 10.1016/S0896-6273(01)80026-X
M3 - Article
C2 - 10482234
AN - SCOPUS:0033180516
VL - 23
SP - 659
EP - 674
JO - Neuron
JF - Neuron
SN - 0896-6273
IS - 4
ER -