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Differential expression of AP‐2α and AP‐2β in the developing chick retina: Repression of R‐FABP promoter activity by AP‐2
Author(s) -
Bisgrove Dwayne A.,
Godbout Roseline
Publication year - 1999
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/(sici)1097-0177(199903)214:3<195::aid-aja3>3.0.co;2-8
Subject(s) - biology , retina , microbiology and biotechnology , transcription factor , reporter gene , transfection , cell culture , gene expression , gene , genetics , neuroscience
Retinal fatty acid binding protein (R‐FABP) is the avian counterpart of murine brain FABP implicated in glial cell differentiation and neuronal cell migration. R‐FABP is highly expressed in the undifferentiated retina and brain of chick embryos. We have previously shown by in vitro studies that the AP‐2 transcription factor binds to a consensus AP‐2 binding site in the R‐FABP promoter region. Based on the expression pattern of AP‐2 in the developing retina and on mutational analysis of the AP‐2 binding site in DNA transfection experiments, we proposed that AP‐2 could be involved in the down‐regulation of R‐FABP transcription. Here, we describe the cDNA isolation of two members of the AP‐2 family expressed in the chick retina, AP‐2α and AP‐2β. We show that R‐FABP mRNA and the AP‐2 factors are expressed in mutually exclusive patterns in the differentiating retina: whereas AP‐2α and AP‐2β are selectively expressed either in amacrine, or in amacrine and horizontal cells, respectively, R‐FABP mRNA is found in Müller glial cells and/or bipolar cells. Furthermore, a decrease in R‐FABP‐ dependent expression is obtained upon co‐transfection of primary retinal cultures with AP‐2 expression vectors and a CAT reporter construct. The early and cell‐specific expression of AP‐2α and AP‐2β in the developing retina suggest a role for this transcription factor family in the early steps of amacrine and horizontal cell differentiation. Repression of the R‐FABP gene in these cells may be an important component of their developmental program. Dev Dyn 1999;214:195–206. © 1999 Wiley‐Liss, Inc.