Drosophila Fezf functions as a transcriptional repressor to direct layer specific synaptic connectivity in the fly visual system
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA685740 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:This SuperSeries is composed of the SubSeries listed below.
2020-12-17 | GSE163311 | GEO
Project description:The layered compartmentalization of synaptic connections, a common feature of nervous systems, underlies proper connectivity between neurons and enables parallel processing of neural information. However, the stepwise development of layered neuronal connections is not well understood. The medulla neuropil of the Drosophila visual system, which comprises 10 discrete layers (M1 to M10), where neural computations underlying distinct visual features are processed, serves as a model system for understanding layered synaptic connectivity. The first step in establishing layer-specific connectivity in the outer medulla (M1 to M6) is the innervation by lamina (L) neurons of one of two broad, primordial domains that will subsequently expand and transform into discrete layers. We previously found that the transcription factor dFezf cell-autonomously directs L3 lamina neurons to their proper primordial broad domain before they form synapses within the developing M3 layer. Here, we show that dFezf controls L3 broad domain selection through temporally precise transcriptional repression of the transcription factor slp1 (sloppy paired 1). In wild-type L3 neurons, slp1 is transiently expressed at a low level during broad domain selection. When dFezf is deleted, slp1 expression is up-regulated, and ablation of slp1 fully rescues the defect of broad domain selection in dFezf-null L3 neurons. Although the early, transient expression of slp1 is expendable for broad domain selection, it is surprisingly necessary for the subsequent L3 innervation of the M3 layer. DFezf thus functions as a transcriptional repressor to coordinate the temporal dynamics of a transcriptional cascade that orchestrates sequential steps of layer-specific synapse formation.
| S-EPMC8020669 | biostudies-literature
Project description:Purpose: Information processing in the brain relies on precise patterns of synapses between neurons. The molecular mechanisms by which this specificity is achieved remains elusive. In the medulla of the Drosophila visual system, different neurons form synaptic connections in different layers. Methods: we developed methods to purify seven neuronal cell types (R7, R8 and L1-L5 neurons) using Fluorescence Activated Cell Sorting. Results: we show that neurons with different synaptic specificities express unique combinations of mRNAs encoding hundreds of cell surface and secreted proteins. Using RNA sequencing and MiMIC-based protein tagging, we demonstrate that 21 paralogs of the Dpr family, a subclass of Immunoglobulin (Ig)-domain containing proteins, are expressed in unique combinations in homologous neurons with different layer-specific synaptic connections. Dpr interacting proteins (DIPs), comprising nine paralogs of another subclass of Ig superfamily proteins, are expressed in a complementary layer-specific fashion in a subset of synaptic partners. We propose that pairs of Dpr/DIP paralogs contribute to layer-specific patterns of synaptic connectivity. Conclusions: This complexity is mirrored by the complexity of the cell surface and secreted molecules expressed by each of the R cell and lamina neurons profiled in this study. How this complexity contributes to specificity remains elusive, but the convergence of improved histological, genetic and molecular tools promises to provide important insights into the molecular recognition strategies controlling synaptic specificity. We chose 7 time points for RNA-seq analysis of R cells during pupal development corresponding to 24, 35, 40, 45, 53, 65 and 96 hrs after pupal formation (APF).
2015-12-17 | E-GEOD-68235 | biostudies-arrayexpress
Project description:SAGA-mediated H2B deubiquitination controls the development of neuronal connectivity in the Drosophila visual system
2008-06-23 | E-TABM-383 | biostudies-arrayexpress
Project description:How our brain generates diverse neuron types that assemble into precise neural circuits remains unclear. Using Drosophila lamina neuron types (L1-L5), we show that the primary homeodomain transcription factor (HDTF) Brain-specific homeobox (Bsh) is initiated in progenitors and maintained in L4/L5 neurons to adulthood. Bsh activates secondary HDTFs Ap (L4) and Pdm3 (L5) and specifies L4/L5 neuronal fates while repressing the HDTF Zfh1 to prevent ectopic L1/L3 fates (control: L1-L5; Bsh-knockdown: L1-L3), thereby generating lamina neuronal diversity for normal visual sensitivity. Subsequently, in L4 neurons, Bsh and Ap function in a feed-forward loop to activate the synapse recognition molecule DIP-β, thereby bridging neuronal fate decision to synaptic connectivity. Expression of a Bsh:Dam specifically in L4 reveals Bsh binding to the DIP-β locus and additional candidate L4 functional identity genes. We propose that HDTFs function hierarchically to coordinate neuronal molecular identity, circuit formation, and function. Hierarchical HDTFs may represent a conserved mechanism for linking neuronal diversity to circuit assembly and function.
2023-11-05 | GSE246726 | GEO
Project description:Purpose: Information processing in the brain relies on precise patterns of synapses between neurons. The molecular mechanisms by which this specificity is achieved remains elusive. In the medulla of the Drosophila visual system, different neurons form synaptic connections in different layers. Methods: we developed methods to purify seven neuronal cell types (R7, R8 and L1-L5 neurons) using Fluorescence Activated Cell Sorting. Results: we show that neurons with different synaptic specificities express unique combinations of mRNAs encoding hundreds of cell surface and secreted proteins. Using RNA sequencing and MiMIC-based protein tagging, we demonstrate that 21 paralogs of the Dpr family, a subclass of Immunoglobulin (Ig)-domain containing proteins, are expressed in unique combinations in homologous neurons with different layer-specific synaptic connections. Dpr interacting proteins (DIPs), comprising nine paralogs of another subclass of Ig superfamily proteins, are expressed in a complementary layer-specific fashion in a subset of synaptic partners. We propose that pairs of Dpr/DIP paralogs contribute to layer-specific patterns of synaptic connectivity. Conclusions: This complexity is mirrored by the complexity of the cell surface and secreted molecules expressed by each of the R cell and lamina neurons profiled in this study. How this complexity contributes to specificity remains elusive, but the convergence of improved histological, genetic and molecular tools promises to provide important insights into the molecular recognition strategies controlling synaptic specificity.
2015-12-17 | GSE68235 | GEO
Project description:Transplantation is a clinically relevant approach for brain repair, but much remains to be understood about influences of the disease environment in the host on transplant connectivity. To explore the influence of ageing and amyloid pathology in Alzheimer's disease (AD) we examined graft connectivity using monosynaptic Rabies virus tracing in APP/PS1 mice and in 16-18 month-old wild type mice. Neurons differentiated within 4 weeks and integrated well into the host visual cortex receiving input from the regions appropriate for visual cortex. Surprisingly, however, we found a prominent several-fold increase in local visual cortex input connectivity in both amyloid-loaded and aged environment. State-of-the-art deep proteome analysis using mass spectrometry provides first insights into the composition of environments promoting or not local exuberant input connectivity. These data therefore highlight the key role of the host pathology in shaping the input connectome calling for caution in extrapolating from one to another pathological condition.
2022-08-12 | PXD023407 | Pride
Project description:Visual processing depends on sensitive and balanced synaptic neurotransmission. Extracellular matrix proteins in the environment of cells are key modulators in synaptogenesis and synaptic plasticity. In the present study, we provide evidence that the combined loss of the four extracellular matrix components brevican, neurocan, tenascin-C and tenascin-R in quadruple knockout mice leads to severe retinal dysfunction and diminished visual motion processing in vivo. Remarkably, impaired visual motion processing was accompanied by a developmental loss of cholinergic direction-selective starburst amacrine cells. Additionally, we noted imbalance of inhibitory and excitatory synaptic signaling in the quadruple knockout retina. Collectively, the study offers novel insights into the functional importance of four key extracellular matrix proteins for retinal function, visual motion processing and synaptic signaling.
2023-12-18 | GSE230425 | GEO
Project description:Precise control of gene expression plays fundamental roles in brain development, but the roles of chromatin regulators in neuronal connectivity have remained poorly understood. Here, we find that depletion of the nucleosome remodeling and deacetylation (NuRD) complex in the cerebellar cortex by in vivo RNAi in rats and conditional knockout of the core NuRD subunit Chd4 in mice profoundly impairs the establishment of granule neuron parallel fiber/Purkinje cell synapses. In RNA-Seq analyses of Chd4 conditional knockout mice, we identify a set of nearly 200 genes that are repressed by the NuRD complex in the cerebellum in vivo. Genome-wide ChIP-Seq analyses reveal that the NuRD complex selectively decommissions the promoters of NuRD-repressed genes in the cerebellum in vivo by inducing the deacetylation of histone H3K9/14 and H3K27 and demethylation of H3K4 at these genes. Importantly, temporal control of promoter decommissioning and repression of NuRD target genes upon maturation of the cerebellum requires the NuRD complex. Finally, in a targeted in vivo RNAi screen of NuRD-repressed target genes, we identify the transcription factor Nhlh1, the RNA-binding protein Elavl2, and the presynaptic regulator Cplx3 as negative regulators of presynaptic differentiation in the cerebellar cortex. Together, these findings define NuRD-dependent promoter decommissioning as a developmentally regulated programming mechanism that releases the brake on presynaptic differentiation and thereby drives synaptic connectivity in the mammalian brain. Three distinct histone modifications using postnatal day 6 or day 22 cerebella from wild type (WT) or Chd4 conditional knockout (cKO) mice were examined in duplicate using libraries prepared with the Illumina ChIP-Seq DNA Sample Prep Kit and sequenced on the Illumina HiSeq 2000 platform.
2014-08-18 | E-GEOD-57758 | biostudies-arrayexpress
Project description:Microarray expression profiling of manually sorted m-citirin-labeled layer 4 visual cortex star pyramid neurons from deprived and non-deprived hemispheres. Monocular deprivation by TTX-injection (at P12-13 and again at P13-14), followed by manual sorting of m-Citrin-labeled Layer 4 Visual Cortex Star Pyramid neurons in deprived and non-deprived hemispheres. RNA was extracted using PicoPure RNA Isolation Kit, reverse transcribed, and amplified using a standard T7 IVT protocol (Affymetrix Small Sample Target Labeling Assay Version II).
2014-04-12 | E-GEOD-56758 | biostudies-arrayexpress