Project description:Wnt signaling in early eye development, specifically the lens placode shows expression of 12 out of 19 Wnt ligands. We these Wnt activities were suppressed using conditional deletion of Wntless, dramatic phenotypic changes in morphogensis occurred. Microarray analysis of the genes that were changed in response to deletion of Wnt ligands in the developing eye region show direct or indirect responses from the surface ectoderm to the developing RPE and optic cup curvature, creating an overal shape change phenotype in the bilayerd epithelium of the optic cup. Mouse embryos at embryonic stage e10.5 were disected into pbs and eye regions were disected and removed for RNA extraction and hybridization to Affymetrix microarrays. We sought to identify the genes that were changed in response to deletion of Wls from the developing surface ectoderm of the eye region. Genes changed could be the direct or indirect result from deleltion of Wls from the surface ectoderm using the LeCre recombinase gene as a tool for analysis.
Project description:Wnt signaling in early eye development, specifically the lens placode shows expression of 12 out of 19 Wnt ligands. We these Wnt activities were suppressed using conditional deletion of Wntless, dramatic phenotypic changes in morphogensis occurred. Microarray analysis of the genes that were changed in response to deletion of Wnt ligands in the developing eye region show direct or indirect responses from the surface ectoderm to the developing RPE and optic cup curvature, creating an overal shape change phenotype in the bilayerd epithelium of the optic cup.
Project description:Vertebrate eye is derived from the neuroepithelium, surface ectoderm, and extracellular mesenchyme. Eye-specified neuroepithelium forms the optic cup in which spatial separation of three domains is established, namely, the region of multipotent retinal progenitor cells (RPCs), the ciliary margin zone (CMZ) possessing both neurogenic and non-neurogenic potential, and the optic disc (OD), the interface between the optic stalk and the neuroretina. Here, we show by genetic ablation in the developing optic cup that Meis1 and Meis2 homeobox genes function redundantly to maintain the retinal progenitor pool while they simultaneously suppress the expression of genes characteristic of CMZ and OD fates. Furthermore, we demonstrate that Meis transcription factors bind the regulatory regions of RPC-, CMZ-, and OD-specific genes, thus providing a mechanistic insight into the Meis-dependent gene regulatory network. Our work uncovers the essential role of Meis1 and Meis2 as regulators of cell fate competence and guardians of spatial territories in the vertebrate eye.
Project description:Vertebrate eye is derived from the neuroepithelium, surface ectoderm, and extracellular mesenchyme. Eye-specified neuroepithelium forms the optic cup in which spatial separation of three domains is established, namely, the region of multipotent retinal progenitor cells (RPCs), the ciliary margin zone (CMZ) possessing both neurogenic and non-neurogenic potential, and the optic disc (OD), the interface between the optic stalk and the neuroretina. Here, we show by genetic ablation in the developing optic cup that Meis1 and Meis2 homeobox genes function redundantly to maintain the retinal progenitor pool while they simultaneously suppress the expression of genes characteristic of CMZ and OD fates. Furthermore, we demonstrate that Meis transcription factors bind the regulatory regions of RPC-, CMZ-, and OD-specific genes, thus providing a mechanistic insight into the Meis-dependent gene regulatory network. Our work uncovers the essential role of Meis1 and Meis2 as regulators of cell fate competence and guardians of spatial territories in the vertebrate eye.
Project description:In mouse early organogenic stages, a Mab21l1-null mutation causes severe defects in invagination of the lens placode toward optic cup due to its severe defects in both cell proliferation and survival, which subsequently results in severe microphthalmia after birth. In human, loss of function variants in MAB21L1 have recently been described in Cerebello-Oculo-Facio-Genital syndrome (COFG syndrome). The close similarity between mouse and human phenotypes including microphthalmia indicates the importance of Mab21l1 function in human lens placode. To approach the molecular function of MAB21L1 in eye morphogenesis, we examined single cell transcriptomes in lens placode and its surrounding surface ectoderm at 26 somite stage (E9.25), just prior to the onset of lens defects in Mab21l1-null embryos. Here we demonstrate the identification of several key genes immediately downstream of Mab21l1 function, together with the early lens placode-/surface ectoderm-specific single cell transcriptomes during murine lens placode specification.
Project description:The optic vesicle in the developing embryonic eye contains a multitude of neuroepithelial progenitors that subsequently differentiate into functionally distinct domains of the optic cup, such as the neural retina, pigment epithelium, and optic stalk. To investigate cell-type diversity across early optic vesicles before regionalization of the optic cup, we performed single-cell RNA-sequencing (scRNA-seq) using 7,989 cells from the presumptive eye area in mouse embryos at the 12–26-somite stages at five developmental time points. We demonstrated the presence of seven optic vesicle populations, including three unique cell types located in the ventricular surface or dorsoventral areas of the optic vesicle structure. Moreover, the remaining four populations of retinal progenitor cells could be classified according to their stage-dependent time point, and these cells exhibited altered expression of several structural and metabolic key genes, such as Col9a1 and Ckb, just before regionalization of the optic cup. From these data, we provide the first report on stage-dependent transcriptional profiles during initial retinal specification at single-cell resolution and highlight the unexpected developmental heterogeneity of the murine optic vesicle structure.
Project description:Embryonic stem (ES) cells have a remarkable capacity to self-organize complex, multi-layered optic cups in vitro via a culture technique called SFEBq. During both SFEBq and in vivo optic cup development, Rax (Rx) expressing neural retina epithelial (NRE) tissues utilize Fgf and Wnt/β-catenin signalling pathways to differentiate into neural retina (NR) and retinal-pigmented epithelial (RPE) tissues, respectively. How these signaling pathways affect gene expression during optic tissue formation has remained largely unknown, especially at the transcriptome scale. We generated Day 10 Rx+ optic tissue using SFEBq, exposed these tissues to either Fgf or Wnt/β-catenin stimulation, and assayed their gene expression at Days 12 and 15 using RNA-Seq. We measured gene expression in these 5 sample groups in biological triplicate using RNA-seq (Illumina HiSeq) .
Project description:Embryonic stem (ES) cells have a remarkable capacity to self-organize complex, multi-layered optic cups in vitro via a culture technique called SFEBq. During both SFEBq and in vivo optic cup development, Rax (Rx) expressing neural retina epithelial (NRE) tissues utilize Fgf and Wnt/β-catenin signalling pathways to differentiate into neural retina (NR) and retinal-pigmented epithelial (RPE) tissues, respectively. How these signaling pathways affect gene expression during optic tissue formation has remained largely unknown, especially at the transcriptome scale.
Project description:Optic fissue is a transient opening on the ventral side of developing optic cup. Failure in optic fissue closure will cause coloboma formation. The aim of this study was to compare optic fissue transcriptome with center optic cup to find optic fissue specific genes.