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SRP181857
Drosophila melanogaster
41 Downloadable Samples
Illumina HiSeq 2000
Description
Control of metazoan embryogenesis shifts from maternal to zygotic gene products as the zygotic genome becomes transcriptionally activated. In Drosophila, zygotic genome activation (ZGA) begins with a minor wave, but technical challenges have hampered the identification of early transcripts or obscured the onset of their transcription. Here, we develop an approach to isolate transcribed mRNAs and apply it over the course of the minor wave and the start of the major wave of Drosophila ZGA. Our results increase known genes of the minor wave by 10 fold and show that this wave is continuous and gradual. Transposable-element mRNAs are also produced, but discontinuously. Genes in the early and middle part of the minor wave are short with few if any introns, and their transcripts are frequently aborted and tend to have retained introns, suggesting that inefficient splicing as well as rapid cell divisions constrain the lengths of early transcripts. Overall design: The goal of this study is to use NGS to identify zygotic transcripts produced during early zygotic genome activation in Drosophila.
Publication Title
Early genome activation in <i>Drosophila</i> is extensive with an initial tendency for aborted transcripts and retained introns.
Sample Metadata Fields
Subject
View Samples- Drosophila melanogaster
- 4 Downloadable Samples
- Illumina HiSeq 2000
Description
We performed mRNA-seq from hand-dissected fat body tissue from 68hr (after egg laying, AEL) and 92hr AEL Drosophila melanogaster larvae. Fat body was dissected from wild-type (OrR) males and testes were removed. We examined gene expression genome-wide with particular focus on genes in the underreplicated regions in the fat body. Overall design: Sequencing of poly-A selected RNA from 68hr AEL and 92hr AEL wild-type (OrR) Drosophila melanogaster male larvae. Sequences analyzed by Illumina sequencing. Two biological replicates are included for each developmental sample.
Publication Title
Dynamic changes in ORC localization and replication fork progression during tissue differentiation.
Sample Metadata Fields
Sex, Specimen part, Subject
View Samples- Drosophila melanogaster
- 54 Downloadable Samples
- Illumina HiSeq 2000
Description
We use mRNA-seq in combination with polysome profiling to determine translational status for all mRNAs in Drosophila mature oocytes and activated eggs. Puromycin-treated lysates are used as a negative control in polysome profiling experiments. Additionally, we use ribosome footprinting to globally measure translational efficiency of mRNAs in wild type mature oocytes as well as wild type and png mutant activated eggs. Overall design: Lysates of hand-dissected Drosophila mature oocytes (containing ~540 µg of total RNA) were subjected to separation by velocity sedimentation through sucrose gradients. In this way, free mRNAs (present in RNPs fraction) or those comigrating with ribosomal subunits (40S or 60S+80S fractions) or with varying numbers of bound ribosomes (low polysomes (2-4 ribosomes), medium polysomes (5-9 ribosomes), and heavy polysomes (more than 10 ribosomes) can be separated based on their size and collected as sucrose gradient fractions. To compare quantitatively the levels of every mRNA across the polysome gradient fractions, we added 5ng of S. cerevisiae mRNA as an exogenous spike-in to each of the six fractions of interest: RNPs, 40S, 60S+80S, low polysomes, medium polysomes and heavy polysomes. RNA was extraced from these fractions, follwing proteinase K treatment, by hot acid phenol method. In case of unfractionated lysates, RNA was extracted using TRIzol (Invitrogen) according to manufacturer’s instructions. mRNA-seq samples were prepared from 1 µg of total RNA (in case of sucrose gradient fractions and unfractionated lysates) and subject to Illumina based sequencing. Puromycin-treated lysates of mature oocytes or 0-2h Drosophila activated eggs (containing ~540 µg of total RNA) were also subjected to separation by velocity sedimentation through sucrose gradients. Puromycin causes premature termination of elongating ribosomes and thus it can be used to determine whether the mRNAs co-sedimenting with the polysomal peaks (defined here as =5 ribosomes) were actively engaged in translation. As an independent approach to assess translation and obtain information on the position of ribosomes on mRNAs, we employed ribosome footprinting. In addition to analyzing the same samples, as by polysome profiling, we also analyzed png mutant activated eggs by ribosome footprinting. Ribosome footprint profiling measures the number of ribosome-protected fragments (RPFs) derived from the mRNAs of each gene, resulting in a singular value of translational efficiency (TE) for each gene (TE=RPF/RNA).
Publication Title
Widespread changes in the posttranscriptional landscape at the Drosophila oocyte-to-embryo transition.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Drosophila melanogaster
- 4 Downloadable Samples
- Illumina Genome Analyzer II
Description
We use mRNA-seq to transcriptionally profile larval salivary gland tissue from Drosophila third instar larvae. These data provide insights into tissue physiology and can be used to identify tissue specific transcripts. Overall design: Salivary glands were dissected from 200 wandering third instar larvae and the associated fat body was removed.Salivary glands were transferred to Graces unsupplemented medium on ice prior to RNA extraction with TRIzol reagent. mRNA-seq samples were prepared from 10 ug of total RNA and subject to Illumina based sequencing.
Publication Title
Developmental control of gene copy number by repression of replication initiation and fork progression.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Drosophila melanogaster
- 2 Downloadable Samples
- Illumina Genome Analyzer II
Description
We use DSN normalized RNA-seq to transcriptionally profile FACS sorted 16C ovarian follicle cells. These data provide insights into the developmental control of gene expression programmed gene amplificaton. Overall design: Follicle cells were isolated from whole ovaries by trypsinization and filtering and stained with Hoescht. 16C follicle cells were isolated by FACS sorting based on DNA content (Hoescht). RNA was extracted with TRIzol reagent and 100ng of total RNA and used to generate a total library. This library was then subjected to DSN normalization prior to Illumina based sequencing.
Publication Title
Integrative analysis of gene amplification in Drosophila follicle cells: parameters of origin activation and repression.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Mus musculus
- 1 Downloadable Sample
- Illumina Genome Analyzer II
Description
We employed miRNA-seq to profile all miRNAs from a pure population of hand-dissected polyploid TGCs from embryonic day 9.5. These data set of polyploid-specific TGCs microRNAs will provide insights into TGCs differentiation and endoreplication. Overall design: TGCs were micro-dissected from day E9.5 nine implantation sites from C57BL/J6 mice. The portion of the TGCs in direct contact with the spongiotrophoblast layer and the labyrinth layer were manually removed to avoid collecting any polyploid cells from the former or multi-nucleated syncytiotrophoblast cells from the latter.
Publication Title
Fundamental differences in endoreplication in mammals and Drosophila revealed by analysis of endocycling and endomitotic cells.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 1 Downloadable Sample
- Illumina Genome Analyzer II
Description
We employed RNA-seq to transcriptionally profile a pure population of hand-dissected polyploid TGCs from embryonic day 9.5. These data provide a set of polyploid-specific TGCs transcripts that will aid in the understanding of TGCs differentiation and endoreplication. Overall design: TGCs were micro-dissected from day E9.5 nine implantation sites from C57BL/6J mice. The portion of the TGCs in direct contact with the spongiotrophoblast layer and the labyrinth layer were manually removed to avoid collecting any polyploid cells from the former or multi-nucleated syncytiotrophoblast cells from the latter.
Publication Title
Fundamental differences in endoreplication in mammals and Drosophila revealed by analysis of endocycling and endomitotic cells.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 28 Downloadable Samples
Affymetrix Murine Genome U74A Version 2 Array (mgu74av2)
Description
Nicotine, acting through the neuronal nicotinic acetylcholine receptors (nAChR), can induce seizures in mice. We aimed to study brain transcriptional response to seizure and to identify genes whose expression is altered after nicotine-induced seizures. Whole brains of untreated mice were compared to brains one hour after seizure activity, using Affymetrix U74Av2 microaarays. Experimental groups included wild-type mice and both nicotine-induced seizures sensitive and resistant nAChR mutant mice. Each genotype group received different nicotine doses to generate seizures. This approach allowed the identification of significantly changed genes whose expression was dependent on seizure activity, nicotine administration or both, but not on the type of nAChR subunit mutation or the amount of nicotine injected. Significant expression changes were detected in 62 genes (p < 0.05, FDR correction). Among them, GO functional annotation analysis determined that the most significantly over-represented categories were of genes encoding MAP kinase phosphatases, regulators of transcription and nucleosome assembly proteins. In-silico bioinformatic analysis of the promoter regions of the 62 changed genes detected the significant enrichments of 16 transcription regulatory elements (TREs), creating a network of transcriptional regulatory responses to seizures. The TREs for ATF and SRF were most significantly enriched, supporting their association with seizure activity. Our data suggest that nicotine-induced seizure in mice is a useful model to study seizure activity and its global brain transcriptional response. The differentially expressed genes detected here can help understand the molecular mechanisms underlying seizures in animal models, and may also serve as candidate genes to study epilepsy in humans.
Publication Title
Expression changes in mouse brains following nicotine-induced seizures: the modulation of transcription factor networks.
Sample Metadata Fields
Sex, Age, Treatment
View Samples- Mus musculus
- 20 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Aging is accompanied by expression changes in multiple genes and the brain is one of the tissues most vulnerable to aging. Since the alpha7 nicotinic acetylcholine receptor (nAChR) subunit has been associated with neurodevelopmental disorders and cognitive decline during aging, we hypothesized that its absence might affect gene expression profiles in aged brains. To study whether transcriptional changes occur due to aging, alpha7 deficiency or both, we analyzed whole brain transcriptomes of young (8 week) and aged (2 year) alpha7 deficient and wild-type control mice, using Mouse Genome 430 2.0 microarray. Highly significant expression changes were detected in 47 and 1543 genes (after Bonferroni and FDR correction) in the brains of aged mice compared to young mice, regardless of their genotype. These included genes involved in immune system function and ribosome structure, as well as genes that were previously demonstrated as differentially expressed in aging human brains. Genotype-dependent changes were detected in only 3 genes, Chrna7 which encodes the alpha7 nAChR subunit, and two closely linked genes, likely due to a mouse background effect. Expression changes dependent on age-genotype interaction were detected in 207 genes (with a low significance threshold). Age-dependent differential expression levels were approved in all nine genes that were chosen for validation by real-time RT-PCR. Our results suggest that the robust effect of aging on brain transcription clearly overcomes the almost negligible effect of alpha7 nAChR subunit deletion, and that germline deficiency of this subunit has a minor effect on brain expression profile in aged mice.
Publication Title
The effects of aging vs. α7 nAChR subunit deficiency on the mouse brain transcriptome: aging beats the deficiency.
Sample Metadata Fields
Age
View Samples- Homo sapiens
- 6 Downloadable Samples
- Illumina HiSeq 2500
Description
miR-372-3p target identification mRNA level Overall design: Differential expression analysis 30h post transfection with miR-372-3p mimics
Publication Title
microRNAs with AAGUGC seed motif constitute an integral part of an oncogenic signaling network.
Sample Metadata Fields
Specimen part, Cell line, Treatment, Subject
View Samples