Fig. 3
From: Transcription factor Foxp1 is essential for the induction of choroidal neovascularization
Six3-Cre deletes Foxp1 in the retinal pigment epithelium (RPE) but not endothelial cells. a Polymerase chain reaction (PCR) genotyping of the tail-extracted DNA from the knockout (KO) and control mice. Wild-type (WT) Foxp1 allele generated a band of 211 bp, smaller than that from the floxed Foxp1 (Foxp1fl/fl) (300 bp). The Foxp1 KO (lane 5) was identified by the presence of floxed Foxp1 and the Cre (405 bp) (Foxp1fl/flSix3-Cre+) in the progenies of Foxp1fl/fl and Six3-Cre mice. The littermate control (Foxp1fl/flSix3-Cre−) was characterized to harbor the floxed allele of Foxp1 but without Cre. Lane 1: water; Lane 2: WT Foxp1; Lane 3: Foxp1fl/fl; Lane 4: Foxp1fl/flSix3-Cre−; Lane 5: Foxp1fl/flSix3-Cre+. b Cryostat sections from the adult Six3-Cre transgenic mice crossed with the EGFP-L10a reporter mouse strain. The enhanced green fluorescence (EGFP) indicates that Cre-mediated recombination occurred in the ganglion cell layer (GCL), inner nuclear layer (INL), and RPE. Nuclei were counterstained with DAPI (blue). Scale bar = 20 μm. c Eye sections from the control and Foxp1 KO mice were immunostained with Foxp1 (red), Cre (green), and DAPI (blue). Negative controls were incubated with phosphate buffered solution (PBS) in lieu of the respective primary antibodies. Arrows depict the cells expressing FOXP1 in the RPE in control mice without Six3-Cre. The Foxp1 signal was weaker in the RPE of KO mice (Arrowheads). Scale bar = 10 μm. d Quantification of mean fluorescence intensity of Foxp1 in RPE cells. CH, choroid; ***: P < 0.001, n = 188 cells for the control and 214 for the Foxp1 KO mice. Statistical comparisons were made using Student’s t-test