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Neural retina identity is specified by lens-derived BMP signals.

Pandit T, Jidigam VK, Patthey C, Gunhaga L - Development (2015)

Bottom Line: Subsequently, our results provide evidence that a Rax2-positive eye-field state is not sufficient for the progress to a neural retina identity, but requires BMP signals.In addition, our results argue against any essential role of Wnt or FGF signals during the specification of neural retina cells, but provide evidence that Wnt signals together with BMP activity are sufficient to induce cells of retinal pigment epithelial character.We conclude that BMP activity emanating from the lens ectoderm maintains eye-field identity, inhibits telencephalic character and induces neural retina cells.

View Article: PubMed Central - PubMed

Affiliation: Umeå Centre for Molecular Medicine, Umeå University, Umeå 901 87, Sweden.

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Expression patterns of optic vesicle and anterior forebrain markers. (A,B) Expression patterns of various anterior forebrain markers were analyzed at stage 21 by in situ hybridization on consecutive sections. (A) At stage 21, Rax2 and Vsx2 are expressed in the neural domain, and Mitf expression is restricted to the RPE domain of the optic cup. FoxG1 expression is confined to the dorsal periphery of the optic cup. (B) At stage 21, FoxG1 and Emx2 are strongly expressed in the dorsal telencephalon. Rax2 and Vsx2 are not expressed in the dorsal telencephalon. (C,D) Optic vesicle (OV) explants cultured to approximately stage 21 and analyzed by in situ hybridization on consecutive sections. (C) Stage 9/10 OV explants generated FoxG1+ (25/25) and Emx2+ (25/25) dorsal telencephalic cells, but no Rax2+ (0/25), Vsx2+ (0/25) or Mitf+ (0/25) retinal cells. (D) Stage 13 OV explants generated Rax2+ (15/15) and Vsx2+ (15/15) neural retina cells, and a few FoxG1+ cells in a restricted region (0/15), but no Mitf+ (0/15) RPE cells or Emx2+ (0/15) cells were detected. Scale bars: 100 µm.
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DEV123653F1: Expression patterns of optic vesicle and anterior forebrain markers. (A,B) Expression patterns of various anterior forebrain markers were analyzed at stage 21 by in situ hybridization on consecutive sections. (A) At stage 21, Rax2 and Vsx2 are expressed in the neural domain, and Mitf expression is restricted to the RPE domain of the optic cup. FoxG1 expression is confined to the dorsal periphery of the optic cup. (B) At stage 21, FoxG1 and Emx2 are strongly expressed in the dorsal telencephalon. Rax2 and Vsx2 are not expressed in the dorsal telencephalon. (C,D) Optic vesicle (OV) explants cultured to approximately stage 21 and analyzed by in situ hybridization on consecutive sections. (C) Stage 9/10 OV explants generated FoxG1+ (25/25) and Emx2+ (25/25) dorsal telencephalic cells, but no Rax2+ (0/25), Vsx2+ (0/25) or Mitf+ (0/25) retinal cells. (D) Stage 13 OV explants generated Rax2+ (15/15) and Vsx2+ (15/15) neural retina cells, and a few FoxG1+ cells in a restricted region (0/15), but no Mitf+ (0/15) RPE cells or Emx2+ (0/15) cells were detected. Scale bars: 100 µm.

Mentions: To examine when cells of the eye-field acquire neural retina character, we analyzed the generation of neural retina cells in relation to other eye and forebrain cells. To achieve this, the expression of a panel of markers was monitored in chick (Gallus gallus) embryos from stage 9 to stage 21 of development on consecutive sections (Fig. 1; supplementary material Fig. S1).Fig. 1.


Neural retina identity is specified by lens-derived BMP signals.

Pandit T, Jidigam VK, Patthey C, Gunhaga L - Development (2015)

Expression patterns of optic vesicle and anterior forebrain markers. (A,B) Expression patterns of various anterior forebrain markers were analyzed at stage 21 by in situ hybridization on consecutive sections. (A) At stage 21, Rax2 and Vsx2 are expressed in the neural domain, and Mitf expression is restricted to the RPE domain of the optic cup. FoxG1 expression is confined to the dorsal periphery of the optic cup. (B) At stage 21, FoxG1 and Emx2 are strongly expressed in the dorsal telencephalon. Rax2 and Vsx2 are not expressed in the dorsal telencephalon. (C,D) Optic vesicle (OV) explants cultured to approximately stage 21 and analyzed by in situ hybridization on consecutive sections. (C) Stage 9/10 OV explants generated FoxG1+ (25/25) and Emx2+ (25/25) dorsal telencephalic cells, but no Rax2+ (0/25), Vsx2+ (0/25) or Mitf+ (0/25) retinal cells. (D) Stage 13 OV explants generated Rax2+ (15/15) and Vsx2+ (15/15) neural retina cells, and a few FoxG1+ cells in a restricted region (0/15), but no Mitf+ (0/15) RPE cells or Emx2+ (0/15) cells were detected. Scale bars: 100 µm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4440930&req=5

DEV123653F1: Expression patterns of optic vesicle and anterior forebrain markers. (A,B) Expression patterns of various anterior forebrain markers were analyzed at stage 21 by in situ hybridization on consecutive sections. (A) At stage 21, Rax2 and Vsx2 are expressed in the neural domain, and Mitf expression is restricted to the RPE domain of the optic cup. FoxG1 expression is confined to the dorsal periphery of the optic cup. (B) At stage 21, FoxG1 and Emx2 are strongly expressed in the dorsal telencephalon. Rax2 and Vsx2 are not expressed in the dorsal telencephalon. (C,D) Optic vesicle (OV) explants cultured to approximately stage 21 and analyzed by in situ hybridization on consecutive sections. (C) Stage 9/10 OV explants generated FoxG1+ (25/25) and Emx2+ (25/25) dorsal telencephalic cells, but no Rax2+ (0/25), Vsx2+ (0/25) or Mitf+ (0/25) retinal cells. (D) Stage 13 OV explants generated Rax2+ (15/15) and Vsx2+ (15/15) neural retina cells, and a few FoxG1+ cells in a restricted region (0/15), but no Mitf+ (0/15) RPE cells or Emx2+ (0/15) cells were detected. Scale bars: 100 µm.
Mentions: To examine when cells of the eye-field acquire neural retina character, we analyzed the generation of neural retina cells in relation to other eye and forebrain cells. To achieve this, the expression of a panel of markers was monitored in chick (Gallus gallus) embryos from stage 9 to stage 21 of development on consecutive sections (Fig. 1; supplementary material Fig. S1).Fig. 1.

Bottom Line: Subsequently, our results provide evidence that a Rax2-positive eye-field state is not sufficient for the progress to a neural retina identity, but requires BMP signals.In addition, our results argue against any essential role of Wnt or FGF signals during the specification of neural retina cells, but provide evidence that Wnt signals together with BMP activity are sufficient to induce cells of retinal pigment epithelial character.We conclude that BMP activity emanating from the lens ectoderm maintains eye-field identity, inhibits telencephalic character and induces neural retina cells.

View Article: PubMed Central - PubMed

Affiliation: Umeå Centre for Molecular Medicine, Umeå University, Umeå 901 87, Sweden.

Show MeSH
Related in: MedlinePlus