title: Distinct cis-regulatory elements from the Dlx1/Dlx2 locus mark different progenitor cell populations in the ganglionic eminences and different subtypes of adult cortical interneurons.
abstract: Distinct subtypes of cortical GABAergic interneurons provide inhibitory signals that are indispensable for neural network function. The Dlx homeobox genes have a central role in regulating their development and function. We have characterized the activity of three cis-regulatory sequences involved in forebrain expression of vertebrate Dlx genes: upstream regulatory element 2 (URE2), I12b, and I56i. The three regulatory elements display regional and temporal differences in their activities within the lateral ganglionic eminence (LGE), medial ganglionic eminence (MGE), and caudal ganglionic eminence (CGE) and label distinct populations of tangentially migrating neurons at embryonic day 12.5 (E12.5) and E13.5. We provide evidence that the dorsomedial and ventral MGE are distinct sources of tangentially migrating neurons during midgestation. In the adult cortex, URE2 and I12b/I56i are differentially expressed in parvalbumin-, calretinin-, neuropeptide Y-, and neuronal nitric oxide synthase-positive interneurons; I12b and I56i were specifically active in somatostatin-, vasoactive intestinal peptide-, and calbindin-positive interneurons. These data suggest that interneuron subtypes use distinct combinations of Dlx1/Dlx2 enhancers from the time they are specified through adulthood.
authors.affiliation: Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, Ottawa, Ontario, Canada K1N 6N5.
authors.forename: Noël
authors.initials: N
authors.lastname: Ghanem
authors.forename: Man
authors.initials: M
authors.lastname: Yu
authors.forename: Jason
authors.initials: J
authors.lastname: Long
authors.forename: Gary
authors.initials: G
authors.lastname: Hatch
authors.forename: John L R
authors.initials: JL
authors.lastname: Rubenstein
authors.forename: Marc
authors.initials: M
authors.lastname: Ekker
mesh_terms: D000375:Aging / Q000235:genetics; D000818:Animals; D001483:Base Sequence / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D002465:Cell Movement / Q000235:genetics; D048430:Cell Shape / Q000235:genetics; D002540:Cerebral Cortex / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D004742:Enhancer Elements, Genetic / Q000235:genetics; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D005819:Genetic Markers; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D007395:Interneurons / Q000378:metabolism*; D019901:Locus Control Region; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009924:Organ Culture Techniques; D050436:Regulatory Elements, Transcriptional / Q000235:genetics*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics*
chemical_list: C088334:Distal-less homeobox proteins; D005819:Genetic Markers; D018398:Homeodomain Proteins; D014157:Transcription Factors