Genome-wide measurement of spatial expression in mutants of Drosophila Melanogaster
Ontology highlight
ABSTRACT:
ORGANISM(S): Drosophila melanogaster
SUBMITTER: Peter Combs
PROVIDER: E-GEOD-71137 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:We sequenced mRNA from transverse slices of embryos from a variety of D. melanogaster mutants (bicoid over-expression, bicoid knockdown, hunchback knocdown, and zelda mutant) at the blastoderm stage to determine genome-wide patterns of gene expression.
2015-07-22 | GSE71137 | GEO
Project description:We have measured by ChIP-seq the distribution of Bicoid protein in Wild Type embryos, and in embryos in which the sole source of Bicoid is expressed at single concentrations representative of individual positions along the morphogen gradient. In addition, we have measured chromatin accessibility and nucleosome positioning by ATAC seq in Wild Type, bicoid mutant, uniform bicoid, and zelda mutant embryos.
2017-09-11 | GSE86966 | GEO
Project description:ChIP-Seq against Bicoid on manually dissected posterior thirds of Drosophila Melanogaster early stage 5 embryos.
2017-10-04 | GSE103695 | GEO
Project description:We sequenced mRNA from transverse slices of 3 wild-type and 3 high bcd copy-number embryos at the blastoderm stage to determine genome-wide patterns of gene expression. mRNA from transverse sections of single D. melanogaster embryos was sequenced
2013-01-16 | E-GEOD-43506 | biostudies-arrayexpress
Project description:In vivo crosslinking studies suggest that the Drosophila transcription factor Bicoid (Bcd) binds to several thousand sites during early embryogenesis, but it is not clear how many of these binding events are functionally important. In contrast, reporter gene studies have identified more than 60 Bcd-dependent enhancers, all of which contain clusters of the consensus binding sequence TAATCC. These studies also identified clusters of TAATCC motifs (inactive fragments) that failed to drive Bcd-dependent activation. In general, active fragments showed higher levels of Bcd-binding in vivo, and were enriched in predicted binding sites for the ubiquitous maternal protein Zelda (Zld). Here we test the role of Zld in Bcd-mediated binding and transcription. Removal of Zld function and mutations in Zld sites caused significant reductions in Bcd-binding to known enhancers, and variable effects on the activation and spatial positioning of Bcd-dependent expression patterns. Genome-wide binding experiments in Zld mutants showed variable effects on Bcd-binding peaks, ranging from strong reductions to significantly enhanced levels of binding. Increases in Bcd binding caused the precocious Bcd-dependent activation of genes that are normally not expressed in early embryos, suggesting that Zld controls the genome-wide binding profile of Bcd at the qualitative level, and is critical for selecting target genes for activation in the early embryo. These results underscore the importance of combinatorial binding in enhancer function, and provide data that will help predict regulatory activities based on DNA sequence. 1-3 hour wild type and zelda mutant embryos were examined for Bicoid binding using Illumina HiSeq 2000. The Bcd antibody is a rabbit polyclonal antiserum raised against full length Drosophila Bcd protein (Ochoa-Espinosa et al. 2009 PNAS). The antiserum was further purified using the Protein A Antibody Purification Kit (Sigma) for ChIP-seq.
2014-05-02 | E-GEOD-55256 | biostudies-arrayexpress
Project description:These experiments measure genome-wide RNA Pol II binding in precisely staged wild-type embryos at five time points spanning the maternal to zygotic transition (nuclear cycles 12 through 14) of Drosophila melanogaster. In addition, RNA Pol II binding at nuclear cycle 13 is measured in embryos mutant for either mei-41/ATR or zelda. To correlate RNA Pol II binding with replication stress, genome-wide profiles of Replication protein A (70kDa subunit, RpA-70 EGFP) were generated in parallel with RNA Pol II for both wild-type and zelda at nuclear cycle 13. Two replicates each for 5 time points for wild type RNA Pol II. Two replicates for mei-41 RNA Pol II, nuclear cycle 13. Two replicates for zelda RNA Pol II, nuclear cycle 13. Two replicates each for Rpa70-EGFP in wild-type or zelda, nuclear cycle 13, matched to the corresponding RNA Pol II sample.
2015-03-05 | E-GEOD-62925 | biostudies-arrayexpress
Project description:Bicoid binding along anteroposterior axis of Drosophila Melanogaster embryos
| PRJNA404072 | ENA
Project description:A conspicuous feature of early animal development is the lack of transcription from the embryonic genome, and it typically takes several hours to several days (depending on the species) until widespread transcription of the embryonic genome begins. Although this transition is ubiquitous, relatively little is known about how the shift from a transcriptionally quiescent to transcriptionally active genome is controlled. We describe here the genome-wide distributions and temporal dynamics of nucleosomes and post-translational histone modifications through the maternal-to-zygotic transition in embryos of the pomace fly Drosophila melanogaster. At mitotic cycle 8, when few zygotic genes are being transcribed, embryonic chromatin is in a relatively simple state: there are few nucleosome-free regions, undetectable levels of the histone methylation marks characteristic of mature chromatin, and low levels of histone acetylation at a relatively small number of loci. Histone acetylation increases by cycle 12, but it is not until cycle 14 that nucleosome-free regions and domains of histone methylation become widespread. Early histone acetylation is strongly associated with regions that we have previously shown are bound in early embryos by the maternally deposited transcription factor Zelda. Most of these Zelda-bound regions are destined to be enhancers or promoters active during mitotic cycle 14, and our data demonstrate that they are biochemically distinct long before they become active, raising the possibility that Zelda triggers a cascade of events, including the accumulation of specific histone modifications, that plays a role in the subsequent activation of these sequences. Many of these Zelda-associated active regions occur in larger domains that we find strongly enriched for histone marks characteristic of Polycomb-mediated repression, suggesting a dynamic balance between Zelda activation and Polycomb repression. Collectively, these data paint a complex picture of a genome in transition from a quiescent to an active state, and highlight the role of Zelda in mediating this transition. We performed genome-wide mapping of histone H3 and 9 types of histone modifications, including H4K5ac, H4K8ac, H3K4me1, H3K4me3, H3K27me3, H3K36me3, H3K9ac, H3K18ac, and H3K27ac by ChIP-seq, in hand-sorted wild-type Drosophila melanogaster embryos at 4 different development time points corresponding to mitotic cycle 7-9, 11-13, 14a-b, and 14c-d, respectively. We also carried out ChIP-seq experiments in zelda mutant embryos after showing that the deposition of histone marks in early embryos strongly correlated with the binding of Zelda in wild-type embryos.
2014-10-16 | E-GEOD-58935 | biostudies-arrayexpress
Project description:Impacts of the Ubiquitous Factor Zelda on Bicoid-dependent DNA-binding and Transcription in Drosophila
| PRJNA239007 | ENA
Project description:In nearly all metazoans, the earliest stages of development are controlled by maternally deposited mRNAs and proteins. The zygotic genome only becomes transcriptionally active hours later. Transcriptional activation is tightly coordinated with the degradation of maternally provided mRNAs during this maternal-to-zygotic transition (MZT). In Drosophila melanogaster, the transcription factor Zelda plays an essential role in widespread activation of the zygotic genome. While Zelda expression is required both maternally and zygotically, the mechanisms by which it functions both during and after the MZT remain unclear. Zelda is a large protein with six C2H2 zinc fingers, but no additional identified domains or predicted enzymatic activities. Using Cas9-mediated genome editing to generate targeted mutations in Zelda, we determined the functional relevance of protein domains conserved amongst Zelda orthologs. Generating these mutations in vivo revealed that neither a conserved N-terminal zinc finger nor an acidic patch were required for activity. Similarly, using a variety of Cas9-enabled approaches we showed that a previously identified splice isoform of zelda is dispensable for viability, and the predicted protein product is not expressed at detectable levels. By contrast, we identified a highly conserved zinc-finger domain that is essential for the maternal, but not zygotic functions of Zelda. A mutation in this zinc-finger domain does not interfere with the capacity of Zelda to activate transcription, but rather leads to a hyperactive form of the protein and enhanced Zelda-dependent gene expression. Embryos inheriting this allele from their mothers die late in embryogenesis. These data define a protein domain critical for controlling Zelda activity and, for the first time, identify a separation between the maternal and zygotic requirements for Zelda. This demonstrates that highly regulated levels of Zelda activity are essential for establishing the developmental program during the MZT and that failure to precisely execute this program leads to embryonic lethality.
2017-11-28 | GSE103914 | GEO