In gastrulation, distinct progenitor cell populations are induced and sorted into the three germ layers ectoderm, mesoderm and endoderm. In order to identify genes involved in germ layer specification and morphogenesis, we identified genes differentially expressed between ectodermal and mesendodermal progenitor cells. To do so, we first generated highly enriched pools of ectodermal and mesendodermal progenitor cells. Mesendodermal cells were generated by over-expressing the Nodal signal Cyclops in wild type embryos and ectodermal cells were taken from mz-one-eyed-pinhead (oep) mutant embryos. We then compared the transcriptome of ectodermal versus mesendodermal cells taken from embryos at 7 hours post fertilization (hpf). In wild type embryos at this stage (70% epiboly), the first ectodermal and mesendodermal progenitor cells have already been sorted into their respective germ layers and ingression of mesendodermal progenitors is still ongoing.
Identification of regulators of germ layer morphogenesis using proteomics in zebrafish.
Age, Specimen part, Subject, Time
View SamplesWe evaluated how different microbial species commonly associated with laboratory-reared Drosophila melanogaster impact host biology at the level of gene expression in the dissected adult gut or the entire adult organism. We observed that guts from gnotobiotic animals associated from the embryonic stage with either zero, one or three bacterial species demonstrated indistinguishable transcriptional profiles. Additionally, we found that the gut transcriptional profiles of animals reared in the presence of the yeast Saccharomyces cerevisiae alone or in combination with bacteria could recapitulate those of conventionally-reared animals. In contrast, we found whole body transcriptional profiles of conventionally-reared animals were distinct from all of the gnotobiotic treatments tested. Our data suggest that adult flies are insensitive to the ingestion of different bacterial species but that prior to adulthood, different microbes impact the host in ways that lead to global transcriptional differences observable across the whole adult body.
No associated publication
Sex, Age, Specimen part, Disease, Cell line, Treatment
View SamplesGene expression activity is heterogeneous in a population of isogenic cells. Identifying the molecular basis of this variability will improve our understanding of phenomena like tumor resistance to drugs, virus infection or cell fate choice. The complexity of the molecular steps and machines involved in transcription and translation could introduce sources of randomness at many levels, but a common constraint to most of these processes is its energy dependence. In eukaryotic cells most of this energy is provided by mitochondria. A clonal population of cells may show a large variability in the number and functionality of mitochondria. Cell-to-cell differences in mitochondrial content, probably originated by asymmetric segregation at cell division, contribute to heterogeneity in gene products.
No associated publication
Sex, Specimen part, Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Reprogramming mouse fibroblasts into engraftable myeloerythroid and lymphoid progenitors.
Specimen part
View SamplesHere we show that hematopoietic transcription factors Scl, Lmo2, Runx1 and Bmi1 can convert a developmentally-distant lineage (fibroblasts) into induced hematopoietic progenitors (iHPs). We analyzed transcriptomic data for cell undergoing the transdifferentiation process at several time-points of the process.
Reprogramming mouse fibroblasts into engraftable myeloerythroid and lymphoid progenitors.
Specimen part
View SamplesMicroRNAs (miRNAs) are endogenous ~22-nucleotide RNAs that mediate important gene-regulatory events by pairing to the mRNAs of protein-coding genes to direct their repression. Repression of these regulatory targets leads to decreased translational efficiency and/or decreased mRNA levels, but the relative contributions of these two outcomes have been largely unknown, particularly for endogenous targets expressed at low-to-moderate levels. Here, we use ribosome profiling to measure the overall effects on protein production and compare these to simultaneously measured effects on mRNA levels. For both ectopic and endogenous miRNA regulatory interactions, lowered mRNA levels account for most (84%) of the decreased protein production. These results show that changes in mRNA levels closely reflect the impact of miRNAs on gene expression and indicate that destabilization of target mRNAs is the predominant reason for reduced protein output.
Mammalian microRNAs predominantly act to decrease target mRNA levels.
Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MYC regulates the core pre-mRNA splicing machinery as an essential step in lymphomagenesis.
Specimen part, Treatment
View SamplesOver-expressed MYC binds to virtually all active promoters within a cell, although with different binding affinities, and modulates gene expression, both positively and negatively. Here, we show that during lymphomagenesis in E-myc transgenic mice, MYC directly up-regulates the transcription of the core snRNP assembly genes, including PRMT5, an arginine methyltransferase, that methylates Sm proteins as an early step in lymphomagenesis. This coordinated regulatory effect is direct and is critical for snRNP biogenesis, the maintenance of effective mRNA splicing and cellular viability in cycling cells, in either fibroblasts or B-cells.
MYC regulates the core pre-mRNA splicing machinery as an essential step in lymphomagenesis.
Specimen part
View SamplesMicroRNAs (miRNAs) are endogenous ~22-nucleotide RNAs that mediate important gene-regulatory events by pairing to the mRNAs of protein-coding genes to direct their repression. Repression of these regulatory targets leads to decreased translational efficiency and/or decreased mRNA levels, but the relative contributions of these two outcomes have been largely unknown, particularly for endogenous targets expressed at low-to-moderate levels. Here, we use ribosome profiling to measure the overall effects on protein production and compare these to simultaneously measured effects on mRNA levels. For both ectopic and endogenous miRNA regulatory interactions, lowered mRNA levels account for most (84%) of the decreased protein production. These results show that changes in mRNA levels closely reflect the impact of miRNAs on gene expression and indicate that destabilization of target mRNAs is the predominant reason for reduced protein output.
Mammalian microRNAs predominantly act to decrease target mRNA levels.
Time
View SamplesMicroRNAs (miRNAs) are endogenous ~22-nucleotide RNAs that mediate important gene-regulatory events by pairing to the mRNAs of protein-coding genes to direct their repression. Repression of these regulatory targets leads to decreased translational efficiency and/or decreased mRNA levels, but the relative contributions of these two outcomes have been largely unknown, particularly for endogenous targets expressed at low-to-moderate levels. Here, we use ribosome profiling to measure the overall effects on protein production and compare these to simultaneously measured effects on mRNA levels. For both ectopic and endogenous miRNA regulatory interactions, lowered mRNA levels account for most (84%) of the decreased protein production. These results show that changes in mRNA levels closely reflect the impact of miRNAs on gene expression and indicate that destabilization of target mRNAs is the predominant reason for reduced protein output.
No associated publication
No sample metadata fields
View Samples