Project description:Multiple cell types can be specified from a single pool of progenitors through the combinatorial activity of transcriptional regulators, which activate distinct developmental programs to establish different cell fates. The zinc finger transcription factor Glass is required for neuronal progenitors in the Drosophila eye imaginal disc to acquire a photoreceptor identity. Glass is also expressed in non-neuronal cone and pigment cells, but its role in these cells is unknown. To examine how Glass activity is affected by the cellular context, we misexpressed it in different tissues. When expressed in neuroblasts of the larval brain or in epithelial cells of the wing disc, Glass activated both a common core set of target genes and distinct gene sets specific to each tissue. In addition to photoreceptor-specific genes, Glass induced markers of cone and pigment cells. Cell type-specific glass mutations generated in cone or pigment cells using somatic CRISPR revealed autonomous developmental defects, and expressing Glass specifically in these cells partially rescued glass mutant phenotypes. Glass thus acts in both neuronal and non-neuronal cells to promote their differentiation into functional components of the eye, suggesting that it is a determinant of organ identity.
Project description:The aim of this data set is to perform a differential expression analysis between wild type eye-antennal imaginal disc and discs that are homozygous glass mutant gl[60j]. This data set is used to validate Glass target gene predictions identified by i-cisTarget on a set of conserved eye-specific genes.
Project description:The integration of extrinsic signaling with cell-intrinsic transcription factors can direct progenitor cells to differentiate into distinct cell fates.In the developingDrosophilaeye, differentiation of photoreceptors R1-R7 requires EGFR signaling mediated by the transcription factor Pointed, and our single-cell RNA-Seq analysis shows that the same photoreceptors require the eye-specific transcription factor Glass. We discovered that ectopic expression of Glass and activation of EGFR signaling synergistically induce neuronal gene expression in the wing disc in a Pointed-dependent manner. Targeted DamID reveals that Glass and Pointed share many binding sites in the genome of developing photoreceptors. Comparison with transcriptomic data shows that Pointed and Glass induce photoreceptor differentiation through intermediate transcription factors, including the redundant homologues Scratch and Scrape, as well as directly activating neuronal genes. Our data reveal synergistic activation of a multi-layered transcriptional network as the mechanism by which EGFR signaling induces neuronal identity in Glass-expressing cells.
Project description:We report the proteome composition of the Drosophila eye – a compound organ that is highly enriched in membrane proteins. The fly eye is a popular model to study the physiology of vision by means of genetic, pharmacological, and dietary interference.While the eye transcriptome and development-related changes of gene expression profiles have been extensively studied, little is known about the eye proteome.we employed GeLC-MS/MS to identify and rank the abundances of 3516 eye proteins. Moreover, we applied our MS Western method to determine the absolute (molar) abundances of a related set of proteins that are important for photoreceptor structure (including maintenance) and function (phototransduction). Altogether, we provide a comprehensive and expandable proteomics resource that will be valuable for a variety of studies of ocular biochemistry, physiology, and development.
Project description:The aim of this study is to identify a set of eye-specific genes across Drosophila species. Species are used as replicates to remove biological noise and identify a core set of conserved eye-developmental genes. We analyze this conserved core using the motif discovery tool i-cisTarget, and identify master regulators of retinal determination, including the Zinc Finger transcription factor Glass.
