The relationship between dlx and gad1 expression indicates highly conserved genetic pathways in the zebrafish forebrain.
The Dlx genes encode a family of transcription factors important for the development of the vertebrate forebrain. These genes have very similar expression domains during the development of the telencephalon in mice and play a role in gamma-aminobutyric acid (GABAergic) interneuron differentiation. We have used triple fluorescent in situ hybridization to study the relative expression domains of the dlx and gad1 genes in the zebrafish telencephalon and diencephalon. We also generated transgenic zebrafish with regulatory elements from the zebrafish dlx1a/2a locus. The zebrafish dlx regulatory elements recapitulated dlx expression in the forebrain and mimicked the relationship between the expression of the dlx genes and gad1. Finally, we show that a putative enhancer located downstream of dlx2b can also activate reporter gene expression in a tissue-specific manner similar to endogenous dlx2b expression. Our results indicate the dlx genes are regulated by an evolutionarily conserved genetic pathway and may play a role in GABAergic interneuron differentiation in the zebrafish forebrain.
MacDonald
Ryan B
RB
Center for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, Ottawa, ON, Canada K1N 6N5.
Debiais-Thibaud
Mélanie
M
Talbot
Jared Coffin
JC
Ekker
Marc
M
D000818:Animals; D004027:Diencephalon / Q000737:chemistry; D005968:Glutamate Decarboxylase / Q000032:analysis*; D018398:Homeodomain Proteins / Q000032:analysis*; D017404:In Situ Hybridization, Fluorescence; D007395:Interneurons / Q000166:cytology; D030781:Organisms, Genetically Modified; D016548:Prosencephalon / Q000254:growth & development / Q000378:metabolism*; D013687:Telencephalon / Q000737:chemistry; D014157:Transcription Factors / Q000032:analysis*; D015027:Zebrafish; D005680:gamma-Aminobutyric Acid
C088334:Distal-less homeobox proteins; D018398:Homeodomain Proteins; D014157:Transcription Factors; D005680:gamma-Aminobutyric Acid; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1