Genetic targeting of principal neurons in neocortex and hippocampus of NEX-Cre mice

Genesis. 2006 Dec;44(12):611-21. doi: 10.1002/dvg.20256.


Conditional mutagenesis permits the cell type-specific analysis of gene functions in vivo. Here, we describe a mouse line that expresses Cre recombinase under control of regulatory sequences of NEX, a gene that encodes a neuronal basic helix-loop-helix (bHLH) protein. To mimic endogenous NEX expression in the dorsal telencephalon, the Cre recombinase gene was targeted into the NEX locus by homologous recombination in ES cells. The Cre expression pattern was analyzed following breeding into different lines of lacZ-indicator mice. Most prominent Cre activity was observed in neocortex and hippocampus, starting from around embryonic day 11.5. Within the dorsal telencephalon, Cre-mediated recombination marked pyramidal neurons and dentate gyrus mossy and granule cells, but was absent from proliferating neural precursors of the ventricular zone, interneurons, oligodendrocytes, and astrocytes. Additionally, we identified formerly unknown domains of NEX promoter activity in mid- and hindbrain. The NEX-Cre mouse will be a valuable tool for behavioral research and the conditional inactivation of target genes in pyramidal neurons of the dorsal telencephalon.

Publication types

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

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics*
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Brain / metabolism*
  • Bromodeoxyuridine
  • DNA Primers
  • Embryonic Stem Cells / metabolism
  • Gene Targeting / methods*
  • Immunohistochemistry
  • Integrases / genetics
  • Integrases / metabolism*
  • Mice
  • Mice, Transgenic
  • Models, Animal*
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism
  • Regulatory Sequences, Nucleic Acid / genetics
  • Reverse Transcriptase Polymerase Chain Reaction


  • Basic Helix-Loop-Helix Transcription Factors
  • DNA Primers
  • Nerve Tissue Proteins
  • Neurod6 protein, mouse
  • Cre recombinase
  • Integrases
  • Bromodeoxyuridine