Polysome profiling and ribosome footprinting of Drosophila mature oocyte and activated egg
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ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE52799 | GEO | 2014/06/12
SECONDARY ACCESSION(S): PRJNA230057
REPOSITORIES: GEO
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Project 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. Lysates of hand-dissected Drosophila mature oocytes (containing ~540 M-NM-<g 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 manufacturerM-bM-^@M-^Ys instructions. mRNA-seq samples were prepared from 1 M-NM-<g 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 M-NM-<g 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 M-bM-^IM-%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).
2014-06-12 | E-GEOD-52799 | biostudies-arrayexpress
Project description:The study tests the hypothesis that maternal mRNA translation in oocytes is sensitive to the environment in which the oocytes mature. Amphiregulin (AREG) is a critical signal for oocyte maturation but also for oocyte developmental competence. Here we have used a genome-wide approach to determine whether the oocyte translational program is affected when oocytes mature in vivo in the absence of AREG. To this aim, polysome arrays were used to define patterns of transcript recruitment to the polysomes in oocytes derived from wild type mice and mice homozygous null for the Areg gene. Forty-eight hours (h) after PMSG injection, mice were stimulated with hCG for 0, or 14 h, and GV, and MII stage oocytes were collected. Polysome bound mRNAs were purified, reverse-transcribed and linearly amplified with WT-Ovation FFPE RNA Amplification System V2 (NuGEN). 5µg cDNA were fragmented and hybridized with Affymetrix Mouse Genome 430.2 array chips. Experiments were done using 3 independent sample sets.
2013-10-02 | E-GEOD-46640 | biostudies-arrayexpress
Project description:The GLD-2 class of poly(A) polymerases regulate the timing of translation of stored transcripts by elongating the poly(A) tails of target mRNAs in the cytoplasm. WISPY is a GLD-2 enzyme that acts in the Drosophila female germline and is required for the completion of the egg-to-embryo transition. Though a handful of WISPY target mRNAs have been identified during both oogenesis and early embryogenesis, we aimed to discover the full range of WISPY targets at each stage. To globally identify these targets, we carried out microarray analysis to look for maternal mRNAs whose poly(A) tails fail to elongate in the absence of WISP function. We examined the polyadenylated portion of the maternal transcriptome in both stage 14 (mature) oocytes and in early embryos that had completed egg activation. Our analysis shows that the poly(A) tails of thousands of maternal mRNAs fail to elongate in wisp-deficient oocytes and embryos. Furthermore, we have identified specific classes of genes that are highly regulated in this manner at each stage. Our study shows that cytoplasmic polyadenylation is a major regulatory mechanism during oocyte maturation and egg activation. Four groups of comparisons: WT vs. wisp total RNA from stage 14 oocytes, WT vs. wisp total RNA from fertilized eggs, WT vs. wisp poly(A)+ RNA from stage 14 oocytes, WT vs. wisp poly(A)+ RNA from fertilized eggs. Each comparison consisted of three independent RNA extractions and each experiment was done with dye-swap pairs as two technical replicates.
2016-05-18 | E-GEOD-81495 | biostudies-arrayexpress
Project description:High resolution polysome fractionation and low-input ribosome profiling of bovine oocytes and preimplantation embryos has enabled us to define the translational landscape of early embryo development at an unprecedented level. We systematically and comparatively analyzed the transcriptome, polysome- and nonpolysome-bound RNA profiles of bovine oocytes and early embryos at 2-, 8-cell, morula, and blastocyst stage, and defined four modes of translational selectivity in bovine preimplantation embryo development: i. selective translation of non-abundant mRNAs, ii. active translating highly expressed mRNAs, iii. Translationally suppressed abundant mRNAs, and iv. Monosomaly occupied mRNAs. A strong selection towards genes involved in mitochondrial function and metabolic pathways was found throughout bovine preimplantation development. We found translatome largely follows transcriptome at oocytes, followed by a marked translational control at 8-cell embryos, which is gradually synchronized at the morula and blastocyst stage. We identified important novel cellular/embryonic functional regulators that being utilized and prioritized for translation at each developmental stage, that accompanies little-known bovine embryonic developmental programming. Together, these data reveal a unique spatiotemporal translational regulation that accompanies bovine preimplantation development.
2022-10-01 | GSE196484 | GEO
Project description:The study tests the hypothesis that maternal mRNA translation in oocytes is sensitive to the environment in which the oocytes mature. Amphiregulin (AREG) is a critical signal for oocyte maturation but also for oocyte developmental competence. Here we have used a genome-wide approach to determine whether the oocyte translational program is affected when oocytes mature in vivo in the absence of AREG. To this aim, polysome arrays were used to define patterns of transcript recruitment to the polysomes in oocytes derived from wild type mice and mice homozygous null for the Areg gene.
2013-10-02 | GSE46640 | GEO
Project description:Translational control is a key regulatory step in the expression of genes as proteins. In plant cells, translational efficiency of mRNAs differs on different mRNA species, and the efficiency dynamically changes in various conditions. To gain a global view of translational control throughout growth and development, we performed genome-wide analysis of polysome association of mRNA over growth and leaf development in Arabidopsis thaliana by applying the mRNAs in polysome to DNA microarray. This analysis revealed that the degree of polysome association of mRNA had different levels depending on mRNA species, and the polysome association changed greatly throughout growth and development for each. In the growth stage, transcripts showed varying changes in polysome association from strongly depressed to unchanged degree, with the majority of transcripts showing dissociation from ribosomes. On the other hand, during leaf development, the polysome association of transcripts showed a normal distribution from repressed to activated mRNAs when comparing between expanding and expanded leaves. In addition, functional category analysis of the microarray data suggested that translational control has a physiological significance in plant growth and development process, especially in category of signaling and protein synthesis. Besides this, we compared changes in polysome association of mRNAs between various conditions and characterized translational controls in each. This result suggested that mRNAs translation might be controlled by complicated mechanisms for response to each condition. Our results highlight the importance of dynamic changes in mRNA translation in plant development and growth. Experiment using 4 developmental stages. Biological replicates: 2. Compared 2DAG and 21DAG, or Young leaves and Mature leaves.
2015-09-01 | E-GEOD-69068 | biostudies-arrayexpress
Project description:Translational control is a key regulatory step in the expression of genes as proteins. In plant cells, translational efficiency of mRNAs differs on different mRNA species, and the efficiency dynamically changes in various conditions. To gain a global view of translational control throughout growth and development, we performed genome-wide analysis of polysome association of mRNA over growth and leaf development in Arabidopsis thaliana by applying the mRNAs in polysome to DNA microarray. This analysis revealed that the degree of polysome association of mRNA had different levels depending on mRNA species, and the polysome association changed greatly throughout growth and development for each. In the growth stage, transcripts showed varying changes in polysome association from strongly depressed to unchanged degree, with the majority of transcripts showing dissociation from ribosomes. On the other hand, during leaf development, the polysome association of transcripts showed a normal distribution from repressed to activated mRNAs when comparing between expanding and expanded leaves. In addition, functional category analysis of the microarray data suggested that translational control has a physiological significance in plant growth and development process, especially in category of signaling and protein synthesis. Besides this, we compared changes in polysome association of mRNAs between various conditions and characterized translational controls in each. This result suggested that mRNAs translation might be controlled by complicated mechanisms for response to each condition. Our results highlight the importance of dynamic changes in mRNA translation in plant development and growth. Experiment using two-flactionated mRNA in 4 developmental stages, Polysomal mRNA vs. total mRNA. Biological replicates: 2. Compared 2DAG and 21DAG, or Young leaves and Mature leaves.
2015-09-01 | E-GEOD-69069 | biostudies-arrayexpress
Project description:Translational control is a key regulatory step in the expression of genes as proteins. In plant cells, translational efficiency of mRNAs differs on different mRNA species, and the efficiency dynamically changes in various conditions. To gain a global view of translational control throughout growth and development, we performed genome-wide analysis of polysome association of mRNA over growth and leaf development in Arabidopsis thaliana by applying the mRNAs in polysome to DNA microarray. This analysis revealed that the degree of polysome association of mRNA had different levels depending on mRNA species, and the polysome association changed greatly throughout growth and development for each. In the growth stage, transcripts showed varying changes in polysome association from strongly depressed to unchanged degree, with the majority of transcripts showing dissociation from ribosomes. On the other hand, during leaf development, the polysome association of transcripts showed a normal distribution from repressed to activated mRNAs when comparing between expanding and expanded leaves. In addition, functional category analysis of the microarray data suggested that translational control has a physiological significance in plant growth and development process, especially in category of signaling and protein synthesis. Besides this, we compared changes in polysome association of mRNAs between various conditions and characterized translational controls in each. This result suggested that mRNAs translation might be controlled by complicated mechanisms for response to each condition. Our results highlight the importance of dynamic changes in mRNA translation in plant development and growth.
2015-09-01 | GSE69069 | GEO
Project description:Translational control is a key regulatory step in the expression of genes as proteins. In plant cells, translational efficiency of mRNAs differs on different mRNA species, and the efficiency dynamically changes in various conditions. To gain a global view of translational control throughout growth and development, we performed genome-wide analysis of polysome association of mRNA over growth and leaf development in Arabidopsis thaliana by applying the mRNAs in polysome to DNA microarray. This analysis revealed that the degree of polysome association of mRNA had different levels depending on mRNA species, and the polysome association changed greatly throughout growth and development for each. In the growth stage, transcripts showed varying changes in polysome association from strongly depressed to unchanged degree, with the majority of transcripts showing dissociation from ribosomes. On the other hand, during leaf development, the polysome association of transcripts showed a normal distribution from repressed to activated mRNAs when comparing between expanding and expanded leaves. In addition, functional category analysis of the microarray data suggested that translational control has a physiological significance in plant growth and development process, especially in category of signaling and protein synthesis. Besides this, we compared changes in polysome association of mRNAs between various conditions and characterized translational controls in each. This result suggested that mRNAs translation might be controlled by complicated mechanisms for response to each condition. Our results highlight the importance of dynamic changes in mRNA translation in plant development and growth.
2015-09-01 | GSE69068 | GEO
Project description:In animals, egg activation triggers a cascade of posttranscriptional events that act on maternally synthesized RNAs. We show that, in Drosophila, the PAN GU (PNG) kinase sits near the top of this cascade, triggering translation of SMAUG (SMG), a multifunctional posttranscriptional regulator conserved from yeast to humans. Although PNG is required for cytoplasmic polyadenylation of smg mRNA, it regulates translation via mechanisms that are independent of its effects on the poly(A) tail. Analyses of mutants suggest that PNG relieves translational repression by PUMILIO (PUM) and one or more additional factors, which act in parallel through the smg mRNA's 3' untranslated region (UTR). Microarray-based gene expression profiling shows that SMG is a major regulator of maternal transcript destabilization. SMG-dependent mRNAs are enriched for gene ontology annotations for function in the cell cycle, suggesting a possible causal relationship between failure to eliminate these transcripts and the cell cycle defects in smg mutants. Keywords: Identification of Maternal mRNAs
2007-09-14 | GSE8910 | GEO