[Abstract Title]. - Society for Neuroscience

This area-specific difference in rates of proliferation is accompanied by higher levels of p27kip1
expression in area 18 compared to area 17 precursors. Preliminary TLV recordings indicate that
radial migration is faster in area 17 compared to area 18. Migrating neurons in area 17 show
higher cytoplasmic levels of p27kip1 than area 18 neurons. These results point to the role of
p27kip1 in the coordinated and area-specific regulation of rates of neuronal production and
migration.
Disclosures: E. Gautier, None; N. Doerflinger, None; V. Cortay, None; P. Giroud, None; H.
Kennedy, None; C. Dehay, None; M. Berland, None; C. Huissoud, None.
Poster
230. Cell Migration: Molecules Mediating Migration
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 230.20/B10
Topic: A.02.c. Cell migration
Support: Canadian Institutes of Health Research (CIHR) Grant, MOP14460
Nina Ireland, NIMH RO1 MH49428-01 and K05MH065670
Title: Characterization of a distinct subpopulation of striatal projection neurons expressing the
Dlx genes in the basal ganglia through the activity of the I56ii enhancer
Authors: *M. YU 1 , N. GHANEM 1 , L. POITRAS 1 , J. L. R. RUBENSTEIN 2 , M. EKKER 1 ;
1 CAREG, Dept. of Biol., Univ. of Ottawa, Ottawa, ON, Canada; 2 Nina Ireland Lab. of
Developmental Neurobiology, Dept. of Psychiatry, Univ. of California at San Francisco, San
Francisco, CA
Abstract: Regulation of region-specific neuronal differentiation and migration in the developing
forebrain is a complex mechanism requiring the involvement of various transcription factors
such as the Dlx genes. At least four cis-acting regulatory elements (CREs) are responsible for the
Dlx transcriptional regulation in the subcortical telencephalon and the rostral diencephalon.
These include I12b and URE2 in the Dlx1/2 bigene cluster, and, I56i and I56ii in the Dlx5/6
bigene cluster. We previously reported that URE2, I12b, and I56i, mark different progenitor cell
populations in the ganglionic eminences as well as different subtypes of adult cortical
interneurons (Ghanem et al, J Neurosci, 27, 5012-22, 2007). Here, we carried out a detailed
spatial and temporal analysis of the I56ii CRE activity in the developing telencephalon between
E10.5 and E15.5. Using the lacZ reporter gene expression in transgenic mice, we compared its
activity with the other three Dlx CREs. We show that I56ii marks distinct group(s) of neurons