The concept of germ layers has been one of the foremost organizing principles in developmental biology, classification, systematics and evolution for 150 years. Of the three germ layers, the mesoderm is found in bilaterian animals but is absent in species in the phyla Cnidaria and Ctenophora, which has been taken as evidence that the mesoderm was the final germ layer to evolve. The origin of the ectoderm and endoderm germ layers, however, remains unclear, with models supporting the antecedence of each as well as a simultaneous origin. Here we determine the temporal and spatial components of gene expression spanning embryonic development for all Caenorhabditis elegans genes and use it to determine the evolutionary ages of the germ layers. The gene expression program of the mesoderm is induced after those of the ectoderm and endoderm, thus making it the last germ layer both to evolve and to develop. Strikingly, the C. elegans endoderm and ectoderm expression programs do not co-induce; rather the endoderm activates earlier, and this is also observed in the expression of endoderm orthologues during the embryology of the frog Xenopus tropicalis, the sea anemone Nematostella vectensis and the sponge Amphimedon queenslandica. Querying the phylogenetic ages of specifically expressed genes reveals that the endoderm comprises older genes. Taken together, we propose that the endoderm program dates back to the origin of multicellularity, whereas the ectoderm originated as a secondary germ layer freed from ancestral feeding functions. Overall design: Two temporal assays of Caenorhabditis elegans embryonic development, starting at the zygote: (a) Embryos collected at fixed (~10 minute) time intervals. (b) Embryo segregates, up to five lines of blastomeres, isolated in reference to mitotic events. There were 184 samples in total, representing 100 distinct data points (50 in each assay).
Spatiotemporal transcriptomics reveals the evolutionary history of the endoderm germ layer.
Subject, Time
View SamplesThe interaction between a pathogen and a host is a highly dynamic process in which both agents activate complex programs. Here, we introduce a single-cell RNA-Seq method (scDual-Seq) that simultaneously captures both host and pathogen transcriptomes and use it to study the process of infection of individual mouse macrophages with the intracellular pathogen Salmonella typhimurium. Among the infected macrophages, we found three subpopulations and we show evidence for a linear progression through these subpopulations, supporting a model in which these three states correspond to consecutive stages of infection. Overall design: 96 single cells in 4 time point of infection (0,2.5,4,8 hours after infection)
scDual-Seq: mapping the gene regulatory program of Salmonella infection by host and pathogen single-cell RNA-sequencing.
Cell line, Subject, Time
View SamplesThe interaction between a pathogen and a host is a highly dynamic process in which both agents activate complex programs. Here, we introduce a single-cell RNA-Seq method (scDual-Seq) that simultaneously captures both host and pathogen transcriptomes and use it to study the process of infection of individual mouse macrophages with the intracellular pathogen Salmonella typhimurium. Among the infected macrophages, we found three subpopulations and we show evidence for a linear progression through these subpopulations, supporting a model in which these three states correspond to consecutive stages of infection. Overall design: 40 single cells, 6 ten cells bulk, 2 hundred cells bulk, in two time point of infection (0,4 hours after infection)
scDual-Seq: mapping the gene regulatory program of Salmonella infection by host and pathogen single-cell RNA-sequencing.
Cell line, Subject, Time
View SamplesThe interaction between a pathogen and a host is a highly dynamic process in which both agents activate complex programs. Here, we introduce a single-cell RNA-Seq method (scDual-Seq) that simultaneously captures both host and pathogen transcriptomes and use it to study the process of infection of individual mouse macrophages with the intracellular pathogen Salmonella typhimurium. Among the infected macrophages, we found three subpopulations and we show evidence for a linear progression through these subpopulations, supporting a model in which these three states correspond to consecutive stages of infection. Overall design: a dilution series of mouse and salmonella RNA Please note that the samples are identical to GSM2729237-GSM2729241 and the RNA was extracted simultaneously. The only difference between them is the different protocol by which the libraries were made for sequencing (i.e. CEL-Seq2 or scDual-Seq).
scDual-Seq: mapping the gene regulatory program of Salmonella infection by host and pathogen single-cell RNA-sequencing.
Specimen part, Subject
View SamplesHuman monocyte derived dendritic cells matured via galectin-1 or LPS.
Galectin-1-matured human monocyte-derived dendritic cells have enhanced migration through extracellular matrix.
No sample metadata fields
View SamplesProductive rearrangement of the immunoglobulin heavy chain locus triggers a major developmental checkpoint that promotes limited clonal expansion of pre-B cells, culminating in cell cycle arrest and rearrangement of the kappa () or lambda () light-chain loci. B lineage cells lacking the related transcription factors IRF-4 and IRF-8 undergo a developmental arrest at the cycling pre-B cell stage and are blocked for light-chain recombination. Using Irf-4,8-/- pre-B cells we demonstrate that two pathways converge to synergistically drive light-chain rearrangement, a process that is not simply activated by cell cycle exit. One pathway is directly dependent on IRF-4, whose expression is elevated by pre-BCR signaling. IRF-4 targets the 3 and enhancers to increase locus accessibility and positions a kappa allele away from pericentromeric heterochromatin. The other pathway is triggered by attenuation of IL-7 signaling and results in activation of the intronic enhancer via binding of the transcription factor, E2A. Intriguingly, IRF-4 regulates the expression of CXCR4 and promotes the migration of pre-B cells in response to the chemokine CXCL12. We propose that IRF-4 coordinates the two pathways regulating light-chain recombination by positioning pre-B cells away from IL-7 expressing stromal cells.
Regulation of immunoglobulin light-chain recombination by the transcription factor IRF-4 and the attenuation of interleukin-7 signaling.
No sample metadata fields
View SamplesA dataset for coordinated transcriptome analysis of the effect of ethanol on human embryonic cerebral slices in vitro and on the mouse embryonic cerebral cortex in a in vivo model.
Combined transcriptome analysis of fetal human and mouse cerebral cortex exposed to alcohol.
Time
View SamplesAs Trypanosoma cruzi, the etiological agent of Chagas disease, multiplies in the cytoplasm of nucleated host cells, infection with this parasite is highly likely to affect host cells. We performed an exhaustive transcriptome analysis of T. cruzi-infected HeLa cells using an oligonucleotide microarray containing probes for greater than 47,000 human gene transcripts. In comparison with uninfected cells, those infected with T. cruzi showed greater than threefold up-regulation of 41 genes and greater than threefold down-regulation of 23 genes. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) of selected, differentially expressed genes confirmed the microarray data. Many of these up- and down-regulated genes were related to cellular proliferation, including seven up-regulated genes encoding proliferation inhibitors and three down-regulated genes encoding proliferation promoters, strongly suggesting that T. cruzi infection inhibits host cell proliferation, which may allow more time for T. cruzi to replicate and produce its intracellular nests. These findings provide new insight into the molecular mechanisms by which intracellular T. cruzi infection influences the host cell, leading to pathogenicity.
Transcriptome profile of Trypanosoma cruzi-infected cells: simultaneous up- and down-regulation of proliferation inhibitors and promoters.
No sample metadata fields
View SamplesPurpose: Mutations in several genetic loci lead to cardiac anomalies, with mutations in transcription factor NKX2-5 gene being one of the largest mutations known. Gestational hypoxia, such as seen in high-altitude pregnancy, has been known to affect cardiac development, and this paper aims to uncover information about the underlying mechanisms of this phenomena. Methods: Wild-type female mice were mated with Nkx2-5 mutant males, to produce offsprings. The pregnant females were then separated into two groups, one left in normal air and one breathing hypoxic, 14% oxygen, air from gestation day 10.5 to 12.5. Hearts were dissected from E12.5 embryos, subjected to RNA purification followed by RNA-seq. Wild-hypoxia and mutant-normoxia were compared to control wild-normoxia. Conclusions: The results of our study provide insights into a common molecular mechanism underlying non-genetic/epigenetic and genetic cardiac anomalies. Overall design: Embryonic mice were produced with either wild-type or mutant genomes, and some from each group were exposed to hypoxia during gestation, then physical analysis and RNA sequencing was done on the embryos.
Mechanism Sharing Between Genetic and Gestational Hypoxia-Induced Cardiac Anomalies.
Specimen part, Treatment, Subject
View SamplesDuring cerebellar development, the main portion of the cerebellar plate neuroepithelium (NE) gives birth to Purkinje cells and interneurons, while the germinal zone at its dorsal edge, called the rhombic lip (RL), generates granule cells and cerebellar nuclei neurons. However, it remains elusive how these components work together to generate the intricate structure of the cerebellar anlage. In this study, we found that a polarized cerebellar anlage structure self-organizes in three-dimensional (3D) human ES cell (hESC) culture. This NE is capable of differentiating into electrophysiologically functional Purkinje cells. The addition of FGF19 promotes spontaneous generation of dorsoventrally polarized NE structures containing cerebellar and basal plates. Furthermore, further addition of SDF1 promoted the generation of stratified cerebellar plate NE with RL-like germinal zones self-forming at the edge. Thus, hESC-derived cerebellar progenitors exhibit substantial self-organizing potential for generating a polarized structure reminiscent of the early human cerebellar anlage at the first trimester. Overall design: Examination of mRNA profile in two different treated human ES cells .
Self-organization of polarized cerebellar tissue in 3D culture of human pluripotent stem cells.
No sample metadata fields
View Samples