Regulation of choroid development by the retinal pigment epithelium.
OBJECTIVE
The choroidal vasculature is essential for normal retinal function. However, mechanisms that control choroid development are unknown. In the present study, we provide evidence that the retinal pigment epithelium (RPE) plays an essential role in regulation of the choroid development in the mouse eye.


METHODS
Transgenic mice that transiently express FGF9 in the embryonic RPE were generated. Postnatal eyes were analyzed by histology and in situ hybridizations.


RESULTS
In the transgenic mice, most of the RPE was converted to neural retina. The choroid formed only in regions where patches of RPE were present. The choroid failed to develop in the absence of the RPE.


CONCLUSIONS
The presence of the RPE appears to be required for choroid development, suggesting that molecular interactions between RPE and periocular mesenchyme are essential for melanocyte differentiation and vascular development in the choroid.
Zhao
S
S
Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77381, USA. szhao@lexgen.com
Overbeek
P A
PA
D000818:Animals; D002454:Cell Differentiation; D002829:Choroid / Q000098:blood supply / Q000254:growth & development*; D016228:Endothelial Growth Factors / Q000235:genetics / Q000378:metabolism; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D051525:Fibroblast Growth Factor 9; D005346:Fibroblast Growth Factors / Q000235:genetics / Q000378:metabolism; D017403:In Situ Hybridization; D008222:Lymphokines / Q000235:genetics / Q000378:metabolism; D008297:Male; D008544:Melanocytes / Q000166:cytology; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D008822:Mice, Transgenic; D010857:Pigment Epithelium of Eye / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000235:genetics / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor; D042461:Vascular Endothelial Growth Factor A; D040281:Vascular Endothelial Growth Factor Receptor-1; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D005136:Eye Proteins; C496460:Fgf9 protein, mouse; D051525:Fibroblast Growth Factor 9; D008222:Lymphokines; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D017978:Receptors, Growth Factor; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D005346:Fibroblast Growth Factors; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor; D040281:Vascular Endothelial Growth Factor Receptor-1