The Homeodomain Factor lbx1 Distinguishes Two Major Programs of Neuronal Differentiation in the Dorsal Spinal Cord

Neuron. 2002 May 16;34(4):551-62. doi: 10.1016/s0896-6273(02)00689-x.

Abstract

Dorsal horn neurons in the spinal cord integrate and relay sensory information. Here, we show that the expression of the homeobox gene Lbx1 distinguishes two major neuronal classes generated in the dorsal spinal cord. The Lbx1(-) (class A) and Lbx1(+) (class B) neurons differ in their dependence on roof plate BMP signals for specification and settle in the deep and superficial dorsal horn, respectively. Lbx1 misexpression blocks the differentiation of class A neurons. Conversely, in Lbx1 mutant mice, class B neurons assume the identity of class A neurons. As a consequence, the morphology and neuronal circuitry of the dorsal horn are aberrant. We conclude that Lbx1 distinguishes two major neuronal classes in the dorsal spinal cord and is an important determinant of their distinct differentiation programs.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Afferent Pathways / abnormalities
  • Afferent Pathways / cytology
  • Afferent Pathways / metabolism
  • Animals
  • Animals, Genetically Modified
  • Avian Proteins*
  • Axons / metabolism
  • Axons / ultrastructure
  • Basic Helix-Loop-Helix Transcription Factors
  • Body Patterning / genetics*
  • Cell Differentiation / genetics*
  • Cell Lineage / genetics*
  • Chick Embryo
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Gene Expression Regulation, Developmental / genetics*
  • Homeodomain Proteins / genetics*
  • Homeodomain Proteins / metabolism
  • Mice
  • Mice, Mutant Strains
  • Mitosis / genetics
  • Muscle Proteins / genetics*
  • Muscle Proteins / metabolism
  • Mutation / genetics
  • Nervous System Malformations / genetics
  • Nervous System Malformations / metabolism
  • Nervous System Malformations / pathology
  • PAX7 Transcription Factor
  • Posterior Horn Cells / abnormalities*
  • Posterior Horn Cells / cytology
  • Posterior Horn Cells / metabolism
  • Spinal Nerve Roots / abnormalities
  • Spinal Nerve Roots / cytology
  • Spinal Nerve Roots / metabolism
  • Stem Cells / cytology
  • Stem Cells / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • Ascl1 protein, mouse
  • Avian Proteins
  • Basic Helix-Loop-Helix Transcription Factors
  • DNA-Binding Proteins
  • Homeodomain Proteins
  • LBX1 protein, Gallus gallus
  • Lbx1h protein, mouse
  • Muscle Proteins
  • PAX7 Transcription Factor
  • Pax7 protein, mouse
  • Transcription Factors