Project description:To analyze the expression profile in the Otx2 knock-in (a knock-in mouse line expressing Otx2 from the Crx locus on chromosome 7) and Crx knockout retina, we performed a microarray analysis using wild-type (Crx +/+), Otx2 KI (Crx Otx2/Otx2) and Crx KO (Crx -/-) retina at P12.
Project description:In the vertebrate retina, the Otx2 transcription factor plays a crucial role in the cell fate determination of both rod and cone photoreceptors. Otx2 conditional knockout (CKO) mice exhibited a total absence of rods and cones in the retina due to their cell fate conversion to amacrine-like cells. In order to investigate the entire transcriptome regulated by Otx2 in the developing retina, we performed microarray analysis on the Otx2 CKO retina. In order to clarify the molecular role of Otx2 in transcriptional regulation during development, we investigated the expression profile of the Otx2 CKO retina compared with that of the control retina with the genotype Otx2flox/flox;Crx-cre- using microarrays at two time points, P1 and P12.
Project description:Leber congenital amaurosis (LCA) includes congenital or early-onset blinding diseases, characterized by vision loss together with nystagmus and nonrecordable electroretinogram (ERG). At least 19 genes are associated with LCA. While most LCA is recessive, mutations in the homeodomain transcription factor gene CRX lead to autosomal dominant LCA. The mechanism of CRX-LCA is not understood. Here, we report a new spontaneous mouse mutant carrying a frameshift mutation in Crx (CrxRip). We show that, unlike Crx-/- mouse retina, the dominant Crx c.763del1 mutation in CrxRip results in congenital blindness with complete loss of ERG, yet the photoreceptors do not degenerate. Dominant CRX frameshift mutations associated with LCA mimic the CrxRip phenotype that can be rescued by Crx. RNA-Seq profiling reveals progressive and complete loss of rod differentiation factor Nrl in CrxRip, while residual Nrl remains in Crx-/- retina. Moreover, Nrl partially restores the rod phenotype in CrxRip/+ mice. We show that the binding of Otx2 to Nrl promoter is obliterated in CrxRip mutant, and ectopic Otx2 can rescue the rod phenotype. Therefore, Otx2 is required to maintain Nrl expression in developing rods to consolidate rod fate. Our studies provide the mechanism of congenital blindness caused by dominant CRX mutations and should assist in therapeutic design. Retinal samples were harvested from WT, CrxRip/+, CrxRip/Rip, Crx-/- and Nrl-/- retina at postnatal days 2 and 21 for whole transcriptome sequencing (RNAseq). Each sample included 2 independent frozen retina and experiments were performed in duplicates. RNA-seq transcriptome libraries were constructed from 1 ?g of total RNA.
Project description:Leber congenital amaurosis (LCA) includes congenital or early-onset blinding diseases, characterized by vision loss together with nystagmus and nonrecordable electroretinogram (ERG). At least 19 genes are associated with LCA. While most LCA is recessive, mutations in the homeodomain transcription factor gene CRX lead to autosomal dominant LCA. The mechanism of CRX-LCA is not understood. Here, we report a new spontaneous mouse mutant carrying a frameshift mutation in Crx (CrxRip). We show that, unlike Crx-/- mouse retina, the dominant Crx c.763del1 mutation in CrxRip results in congenital blindness with complete loss of ERG, yet the photoreceptors do not degenerate. Dominant CRX frameshift mutations associated with LCA mimic the CrxRip phenotype that can be rescued by Crx. RNA-Seq profiling reveals progressive and complete loss of rod differentiation factor Nrl in CrxRip, while residual Nrl remains in Crx-/- retina. Moreover, Nrl partially restores the rod phenotype in CrxRip/+ mice. We show that the binding of Otx2 to Nrl promoter is obliterated in CrxRip mutant, and ectopic Otx2 can rescue the rod phenotype. Therefore, Otx2 is required to maintain Nrl expression in developing rods to consolidate rod fate. Our studies provide the mechanism of congenital blindness caused by dominant CRX mutations and should assist in therapeutic design.
Project description:Many transcription factors regulating the production, survival and function of photoreceptor cells in the retina have been identified, but little is known about transcriptional co-regulators in retinal health and disease. Here we show that BCL6 co-repressor (BCOR), a polycomb repressive complex I factor mutated in various cancers, negatively regulates photoreceptor gene expression. Using proteomics and promoter assays, we find that BCOR interacts with the photoreceptor transcription factors OTX2 and CRX, and reduces their ability to activate the promoters of photoreceptor-specific genes, such as Rhodopsin and Nrl. CUT&RUN sequencing further shows that BCOR shares genome-wide binding profiles with CRX/OTX2, consistent with a general co-repression activity. Finally, we identify missense variants in the human BCOR gene in six families with early-onset X-linked inherited retinal degeneration (IRD). Together, this work uncovers BCOR as a co-repressor of OTX2/CRX essential for photoreceptor cell biology and survival.
Project description:In the vertebrate retina, the Otx2 transcription factor plays a crucial role in the cell fate determination of both rod and cone photoreceptors. Otx2 conditional knockout (CKO) mice exhibited a total absence of rods and cones in the retina due to their cell fate conversion to amacrine-like cells. In order to investigate the entire transcriptome regulated by Otx2 in the developing retina, we performed microarray analysis on the Otx2 CKO retina.
Project description:To analyze the expression profile in the Samd7 KO retina, we performed a microarray analysis using wild-type and Samd7 KO retina at P12.
Project description:Otx2 has been shown to be non cell autonomously required for photoreceptor cell survival in the adult mouse RPE. This study aims to identify Otx2 DNA binding profile in both RPE and neural retina to i) identify direct targets of Otx2 in the RPE ii) compare Otx2 binding profile in neural retina and RPE to unveil hidden functions in the neural retina. WT and GFP antibodies were used to perform two independent ChIP-seq experiments using Illumina GAIIx.
Project description:Otx2 has been shown to be non cell autonomously required for photoreceptor cell survival in the adult mouse RPE. This study aims to identify Otx2 DNA binding profile in both RPE and neural retina to i) identify direct targets of Otx2 in the RPE ii) compare Otx2 binding profile in neural retina and RPE to unveil hidden functions in the neural retina.