A dlx2- and pax6-dependent transcriptional code for periglomerular neuron specification in the adult olfactory bulb

J Neurosci. 2008 Jun 18;28(25):6439-52. doi: 10.1523/JNEUROSCI.0700-08.2008.


Distinct olfactory bulb (OB) interneurons are thought to become specified depending on from which of the different subregions lining the lateral ventricle wall they originate, but the role of region-specific transcription factors (TFs) in the generation of OB interneurons diversity is still poorly understood. Despite the crucial roles of the Dlx family of TFs for patterning and neurogenesis in the ventral telencephalon during embryonic development, their role in adult neurogenesis has not yet been addressed. Here we show that in the adult brain, Dlx 1 and Dlx2 are expressed in progenitors of the lateral but not the dorsal subependymal zone (SEZ), thus exhibiting a striking regional specificity. Using retroviral vectors to examine the function of Dlx2 in a cell-autonomous manner, we demonstrate that this TF is necessary for neurogenesis of virtually all OB interneurons arising from the lateral SEZ. Beyond its function in generic neurogenesis, Dlx2 also plays a crucial role in neuronal subtype specification in the OB, promoting specification of adult-born periglomerular neurons (PGNs) toward a dopaminergic fate. Strikingly, Dlx2 requires interaction with Pax6, because Pax6 deletion blocks Dlx2-mediated PGN specification. Thus, Dlx2 wields a dual function by first instructing generic neurogenesis from adult precursors and subsequently specifying PGN subtypes in conjunction with Pax6.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Animals
  • Cell Differentiation / genetics
  • Cell Lineage / genetics*
  • Cells, Cultured
  • Eye Proteins / genetics*
  • Eye Proteins / physiology
  • Female
  • Homeodomain Proteins / genetics*
  • Homeodomain Proteins / physiology
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Neurons / cytology
  • Neurons / physiology*
  • Olfactory Bulb / cytology
  • Olfactory Bulb / growth & development
  • Olfactory Bulb / metabolism*
  • PAX6 Transcription Factor
  • Paired Box Transcription Factors / genetics*
  • Paired Box Transcription Factors / physiology
  • Pregnancy
  • Repressor Proteins / genetics*
  • Repressor Proteins / physiology
  • Transcription Factors / genetics*
  • Transcription Factors / physiology
  • Transcription, Genetic / physiology*


  • Distal-less homeobox proteins
  • Eye Proteins
  • Homeodomain Proteins
  • PAX6 Transcription Factor
  • PAX6 protein, human
  • Paired Box Transcription Factors
  • Pax6 protein, mouse
  • Repressor Proteins
  • Transcription Factors