Runx1 expression defines a subpopulation of displaced amacrine cells in the developing mouse retina.
AML1/Runx1 (Runx1) is a mammalian transcription factor that plays critical roles in regulating the differentiation of a number of different cell types. In the present study, we have utilized mice expressing beta-galactosidase (beta-gal) under the control of the Runx1 promoter to characterize the spatiotemporal expression pattern of Runx1 during retinogenesis. Expression of beta-gal was first detected at embryonic day 13.5 in post-mitotic cells located in the inner retina and overlapped with expression of the early amacrine and ganglion cell marker protein Islet1. During subsequent developmental stages, the number of beta-gal-positive cells increased in a central-to-peripheral gradient until late embryogenesis but then decreased in the early post-natal retina. beta-gal-positive cells were located primarily in the ganglion cell layer by late embryonic/early post-natal stages and were identified as a subpopulation of displaced amacrine cells by the continued expression of Islet1, as well as Pax6, and the coexpression of the amacrine cell subtype-specific markers choline acetyltransferase, calretinin and the 65-kDa isoform of glutamic acid decarboxylase. These findings identify Runx1 as a novel marker for a restricted amacrine cell subtype and suggest a role for this gene in regulating the post-mitotic development of these cells.
Stewart
Lee
L
Center for Neuronal Survival, Montreal Neurological Institute, Montreal, Quebec, Canada.
Potok
Mary Anne
MA
Camper
Sally A
SA
Stifani
Stefano
S
D025042:Amacrine Cells / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D015415:Biomarkers; D002454:Cell Differentiation / Q000502:physiology*; D002465:Cell Movement / Q000235:genetics; D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D017930:Genes, Reporter; D007763:Lac Operon; D051379:Mice; D008822:Mice, Transgenic; D038081:Organogenesis / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D012160:Retina / Q000166:cytology / Q000196:embryology* / Q000254:growth & development*; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000502:physiology; D014157:Transcription Factors / Q000378:metabolism*; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D015415:Biomarkers; D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; C493726:Runx1 protein, mouse; D014157:Transcription Factors; D001616:beta-Galactosidase