RT Journal Article SR Electronic T1 The Divergent Homeobox Gene PBX1 Is Expressed in the Postnatal Subventricular Zone and Interneurons of the Olfactory Bulb JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 2972 OP 2982 DO 10.1523/JNEUROSCI.16-09-02972.1996 VO 16 IS 9 A1 Lori Redmond A1 Susan Hockfield A1 Maria A. Morabito YR 1996 UL http://www.jneurosci.org/content/16/9/2972.abstract AB In the mammalian brain, an important phase of neurogenesis occurs postnatally in the subventricular zone (SVZ). This region consists of a heterogeneous population of cells, some mitotically active, others postmitotic. A subset of mitotically active SVZ precursor cells gives rise to a population of neurons that migrates over a long distance to their final destination, the olfactory bulb. Other SVZ precursor cells continue to proliferate or undergo cell death. The combination of genes that regulates proliferation and cell fate determination of SVZ precursor cells remains to be identified. We have used the rat homolog of the human homeobox gene PBX1 in Northern analysis andin situ hybridization studies to determine the temporal and regional localization of PBX1 expression during embryonic and postnatal rat brain development. PBX1 is expressed embryonically in the telencephalon. In addition, it is expressed at high levels postnatally in the SVZ, in the migratory pathway to the olfactory bulb, and in the layers of the olfactory bulb that are the targets of these migratory neurons. Combining in situhybridization for PBX1 with immunostaining for markers of cell proliferation (PCNA), postmitotic neurons (class III β-tubulin), and glia (GFAP), we show that SVZ proliferating cells and their neuronal progeny express rat PBX1 mRNA, whereas glial cells do not express detectable levels of PBX1. The expression ofPBX1 in SVZ precursor cells and postmitotic neurons suggests a role for PBX1 in the generation of olfactory bulb interneurons and in mammalian neurogenesis.