We performed RNA-seq to profile gene expression in the heads and whole bodies of 32 isofemale fly lines from two divergent microclimates at ''Evolution Canyon'' in Israel (16 fly lines from each microclimate). We also measured RNA editing levels in the head tissue of these flies. Overall design: For each of the 32 isofemale fly lines from ''Evolution Canyon'', gene expression profiles of whole bodies and heads, along with RNA editing profiles of heads of 3-5 day old male flies through RNA-seq.
Regulation of gene expression and RNA editing in Drosophila adapting to divergent microclimates.
Specimen part, Subject
View SamplesSpecification of germ cell fate is fundamental in development. With a highly representative single-cell microarray and rigorous quantitative-PCR analysis, we defined the genome-wide transcription dynamics that create primordial germ cells (PGCs) from the epiblast, a process that exclusively segregates them from their somatic neighbors. We also analyzed the effect of the loss of Blimp1, a key transcriptional regulator, on these dynamics. Our analysis revealed that PGC specification involves complex, yet highly ordered regulation of a large number of genes, proceeding under the strong influence of mesoderm induction with active repression of specific programs such as epithelial-mesenchymal transition, Hox gene activation, cell-cycle progression and DNA methyltransferase machinery. Remarkably, Blimp1 is essential for repressing nearly all the genes normally down-regulated in PGCs relative to their somatic neighbors, whereas it is dispensable for the activation of approximately half of the genes up-regulated in PGCs.
Complex genome-wide transcription dynamics orchestrated by Blimp1 for the specification of the germ cell lineage in mice.
No sample metadata fields
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Induction of mouse germ-cell fate by transcription factors in vitro.
Sex, Specimen part
View SamplesThe germ cell lineage ensures the continuity of life through the generation of male and female gametes, which unite to form a totipotent zygote. We have established a culture system that recapitulates the mouse germ-cell specification pathway: Using cytokines, embryonic stem cells (ESCs)/induced pluripotent stem cells (iPSCs) are induced into epiblast-like cells (EpiLCs) and then into primordial germ cell-like cells (PGCLCs) with capacity both for spermatogenesis and oogenesis, creating an opportunity for understanding and regulating mammalian germ cell development in both sexes in vitro. Here we show that, without cytokines, simultaneous over-expression of three transcription factors (TFs), Blimp1 (also known as Prdm1), Prdm14 and Tfap2c (also known as AP2), directs EpiLCs, but not ESCs, swiftly and highly efficiently into a PGC state with endogenous transcription circuitry. The induction of the PGC state on EpiLCs minimally requires Prdm14 but not Blimp1 or Tfap2c. The TF-induced PGC state reconstitutes key transcriptome and epigenetic reprogramming in PGCs, but bypasses a mesodermal program that accompanies PGC specification in vivo and in vitro by cytokines including BMP4. Importantly, the TF-induced PGC-like cells robustly contribute to spermatogenesis and fertile offspring. Our findings provide not only a novel insight into the transcriptional logic that creates a germ cell state, but also a foundation for the TF-based reconstitution and regulation of mammalian gametogenesis.
Induction of mouse germ-cell fate by transcription factors in vitro.
Sex, Specimen part
View SamplesThe germ cell lineage ensures the continuity of life through the generation of male and female gametes, which unite to form a totipotent zygote. We have established a culture system that recapitulates the mouse germ-cell specification pathway: Using cytokines, embryonic stem cells (ESCs)/induced pluripotent stem cells (iPSCs) are induced into epiblast-like cells (EpiLCs) and then into primordial germ cell-like cells (PGCLCs) with capacity both for spermatogenesis and oogenesis, creating an opportunity for understanding and regulating mammalian germ cell development in both sexes in vitro. Here we show that, without cytokines, simultaneous over-expression of three transcription factors (TFs), Blimp1 (also known as Prdm1), Prdm14 and Tfap2c (also known as AP2), directs EpiLCs, but not ESCs, swiftly and highly efficiently into a PGC state with endogenous transcription circuitry. The induction of the PGC state on EpiLCs minimally requires Prdm14 but not Blimp1 or Tfap2c. The TF-induced PGC state reconstitutes key transcriptome and epigenetic reprogramming in PGCs, but bypasses a mesodermal program that accompanies PGC specification in vivo and in vitro by cytokines including BMP4. Importantly, the TF-induced PGC-like cells robustly contribute to spermatogenesis and fertile offspring. Our findings provide not only a novel insight into the transcriptional logic that creates a germ cell state, but also a foundation for the TF-based reconstitution and regulation of mammalian gametogenesis.
Induction of mouse germ-cell fate by transcription factors in vitro.
Sex
View SamplesThis SuperSeries is composed of the SubSeries listed below.
An improved single-cell cDNA amplification method for efficient high-density oligonucleotide microarray analysis.
No sample metadata fields
View SamplesThe inner cell mass (ICM) of the early blastocyst at E3.5, a source of ES cell derivation, is a morphologically homogeneous population of undifferentiated pluripotent cells that give rise to all embryonic lineages. The immediate application of the newly developed V1V3 method to single cells in this stage of mouse embryos revealed the presence of two populations of cells, one with primitive endoderm expression and the other with pluripotent epiblast-like gene expression. The genes expressed differentially between these two populations were well preserved in morphologically differentiated primitive endoderm and epiblast in the embryos one day later (E4.5), demonstrating that the method successfully detects subtle but essential differences in gene expression at the single-cell level among seemingly homogeneous cell populations. This study provides a strategy to analyze biophysical events in medicine as well as in neural, stem cell, and developmental biology, where small numbers of distinctive or diseased cells play critical roles.
An improved single-cell cDNA amplification method for efficient high-density oligonucleotide microarray analysis.
No sample metadata fields
View SamplesA systems-level understanding of a small but essential population of cells in development or adulthood (e.g., somatic stem cells) requires accurate quantitative monitoring of genome-wide gene expression, ideally from single cells. We report here a strategy to globally amplify mRNAs from single cells for highly quantitative high-density oligonucleotide microarray analysis that combines a small number of directional PCR cycles with subsequent linear amplification. Using this strategy, both the representation of gene expression profiles and reproducibility between individual experiments are unambiguously improved from the original method, along with high coverage and accuracy.
An improved single-cell cDNA amplification method for efficient high-density oligonucleotide microarray analysis.
No sample metadata fields
View SamplesPurpose: Syncytiotrophoblast (STB) is a multi-nucleated, terminally differentiated syncytium that covers the surface of the villous placenta and forms the major interface with maternal blood. It releases placental hormones and plays a primary role in exchange of gases, nutrients and waste products. Alterations in STB development and turnover have been implicated in placental diseases, including preeclampsia (PE). In vitro cell models are badly needed to study STB development and physiology due to inaccessibility to placental tissues during gestation. To establish in vitro STB model system, we generate STB and its mononucleated precursors from human embryonic stem cells (hESC) and profile for RNA content by RNAseq. Methods: H1 Human ESC (WA01) were treated with BMP4, the ALK4/5/7 inhibitor (A83-01), and the FGF2 signaling inhibitor (PD173074) (BAP) to direct them to the trophoblast lineage and provided both STB and extravillous trophoblast. Syncytial areas emerged at day 8 BAP treatment ranged in diameter from ~40 µm to > 100 µm. The intact syncytial areas were isolated by sieving successively through 70 µm and 40 µm mesh cell strainers. The captured cells are recovered by inverting the strainer and rinsing with culture medium to separate large (>70 µm) and middle size cell sheets (40-70 µm). The fraction that passes through both sieves represents cells of smallest diameter (< 40 µm), presumably cytotrophoblast. Total 12 RNA samples from triplicate three size-fractioned BAP treated and three untreated hESC cultured in a FGF2 supplemented medium in parallel were analyzed. Results: The larger > 70 µm areas stained positively for STB markers while ultrastructural analysis clearly revealed multi-nuclear cells with an extensive cytoplasm containing many prominent secretion granules. The larger STB areas also had a larger DNA content that > 70 µm fraction contained 37 times more nuclear content and 40-70 µm fraction did 16 times more. Compared to the < 40 µm cell fraction, these larger cells over-expressed a full repertoire of genes characteristic of STB, e.g. CGA, CGB, PGF, ERVW1, GCM1. The smallest cell fraction had a DNA content consistent with mononuclear diploid cells, contained few secretory granules, and were only weakly positive for STB markers. Conclusion: The data are consistent with the > 70 µm cells being mature STB, while the intermediate fraction may represent a precursor population. Human ESC directed along the trophoblast lineage by BAP treatment offers a useful model for following STB formation in vitro and suggest that this protocol may have utility in studying the basis of certain placental diseases, especially preeclampsia, where placental tissue isolated at term or after pregnancy terminations can only offer limited information. Overall design: Three size fraction mRNA profiles of syncytial areas emerged at day 8 BAP treatment of hESC were generated by deep sequencing along with untreated hESC, in triplicate, using Illumina HiSeq 2500.
Comparison of syncytiotrophoblast generated from human embryonic stem cells and from term placentas.
No sample metadata fields
View SamplesPluripotency, the capacity of embryo-derived stem cells to generate all tissues in the organism, can be induced in somatic cells by nuclear transfer into oocyte, fusion with embryonic stem cells, and for male germ cells by cell culture alone. Recently, murine fibroblasts have been reprogrammed directly to pluripotency by ectopic expression of four transcription factors (Oct4, Sox2, Klf4, and Myc) to yield induced Pluripotent Stem (iPS) cells. Using the same four factors, we have derived iPS cells from human embryonic stem cell-derived fibroblasts, primary human fetal cells, and diverse cells of neonatal and adult human origin. The human iPS cells manifest the colony morphology, gene expression patterns, and epigenetic characteristics of human Embryonic Stem (hES) cells, and form well-differentiated teratomas in immune-deficient mice. These data demonstrate that defined factors can reprogram human cells to pluripotency, and establish a method whereby patient-specific cells might be established in culture.
Reprogramming of human somatic cells to pluripotency with defined factors.
No sample metadata fields
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