Induction of a mesencephalic phenotype in the 2-day-old chick prosencephalon is preceded by the early expression of the homeobox gene en

Neuron. 1991 Jun;6(6):971-81. doi: 10.1016/0896-6273(91)90237-t.


The homeobox gene en, homologous to the gene en-grailed of Drosophila, is expressed in the metencephalic-mesencephalic segment of the vertebrate neural tube. Using quail-chick chimeras, an antibody against en proteins, and cytoarchitectonic techniques, we demonstrate that metencephalon transplanted to prosencephalon, at E2, maintains a high level of en proteins and its presumptive cerebellar fate. The ectopic metencephalon induces in the contiguous host prosencephalon the expression of en and, subsequently, a mesencephalic phenotype. These related genetic and phenotypic expressions indicate that the transcriptional regulatory en gene is involved in cerebellar and mesencephalic cyto-differentiation. The expression of en can also be induced in chick prosencephalon by a mammalian metencephalic graft, indicating that the factors regulating the transcription of en are phylogenetically well conserved.

MeSH terms

  • Animals
  • Antibodies, Monoclonal
  • Brain Tissue Transplantation / physiology*
  • Chick Embryo
  • Chimera
  • Drosophila / genetics
  • Drosophila Proteins
  • Embryo, Nonmammalian
  • Fetal Tissue Transplantation / physiology
  • Gene Expression
  • Genes, Homeobox*
  • Homeodomain Proteins*
  • Insect Hormones / analysis
  • Insect Hormones / genetics*
  • Mesencephalon / embryology
  • Mesencephalon / physiology*
  • Phenotype
  • Pons / embryology
  • Pons / physiology*
  • Quail
  • Transcription Factors / analysis
  • Transcription Factors / genetics*


  • Antibodies, Monoclonal
  • Drosophila Proteins
  • En protein, Drosophila
  • Homeodomain Proteins
  • Insect Hormones
  • Transcription Factors