Function of Rx, but not Pax6, is essential for the formation of retinal progenitor cells in mice.
Rx plays a critical role in eye formation. Targeted elimination of Rx results in embryos that do not develop eyes. In this study, we have investigated the expression of Otx2, Six3, and Pax6 in Rx deficient embryos. We find that these genes show normal activation in the anterior neural plate in Rx-/- embryos, but they are not upregulated in the area of the neural plate that would form the primordium of the optic vesicle. In contrast, in homozygous Small eye embryos that lack Pax6 function, Rx shows normal activation in the anterior neural plate and normal upregulation in the optic vesicle/retinal progenitor cells. This suggests that neither Rx expression nor the formation of retinal progenitor cells is dependent on a functional copy of the Pax6 gene, but that Pax6 expression and the formation of the progenitor cells of the optic cup is dependent on a functional copy of the Rx gene.
Zhang
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L
Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
Mathers
P H
PH
Jamrich
M
M
D000818:Animals; D005136:Eye Proteins; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000235:genetics*; D051379:Mice; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics; D051857:Otx Transcription Factors; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D010641:Phenotype; D012097:Repressor Proteins; D012160:Retina / Q000166:cytology / Q000196:embryology*; D013234:Stem Cells; D015534:Trans-Activators / Q000235:genetics; D014157:Transcription Factors; D000097607:Homeobox Protein SIX3
D005136:Eye Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D051857:Otx Transcription Factors; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D000097607:Homeobox Protein SIX3; C497660:Otx2 protein, mouse; C000605732:Pax6 protein, mouse; C105441:Rax protein, mouse; C111251:Rx protein, vertebrate