Sentences with phrase «es cell differentiation»

The functional annotations of all the clusters with ≥ 10 transcripts, which were obtained using the on GO classification categories of the g: Profiler tool for all the genes in each cluster, are shown in Table 2 (for downregulated genes during ES cell differentiation) and Table 3 (for upregulated genes).

To examine the action of individual pathways in toto during ES cell differentiation, the FunGenES database was given an additional feature called «Pathway Animations» that depict dynamic changes in specific genetic, signaling or metabolic pathways viewed in time - related animations based on the KEGG annotation [44], [56].

These genes have been also implicated in the gastrulation phase of embryogenesis [55] indicating that «Time Series» clusters provide a comprehensive collection of genes expressed at specific stages of ES cell differentiation and early embryonic development.

A. Average expression levels of Global Clusters 4, 12, 15, 20 and 30 that contain up regulated transcripts during ES cell differentiation.

Specifically, we have generated clusters of transcripts that behave the same way under the entire spectrum of the sixty - seven experimental conditions; we have assembled genes in groups according to their time of expression during successive days of ES cell differentiation; we have included expression profiles of specific gene classes such as transcription regulatory factors and Expressed Sequence Tags; transcripts have been arranged in «Expression Waves» and juxtaposed to genes with opposite or complementary expression patterns; we have designed search engines to display the expression profile of any transcript during ES cell differentiation; gene expression data have been organized in animated graphs of KEGG signaling and metabolic pathways; and finally, we have incorporated advanced functional annotations for individual genes or gene clusters of interest and links to microarray and genomic resources.

Taking into account that ES cells are isolated at embryonic day 3.5 post fertilization, the sequential appearance of genes specific for gastrulation, mesoderm formation, hemopoiesis, cardiopoiesis and neurogenesis during ES cell differentiation follows the timing of comparable developmental stages in embryonic development.

The bottom row consists of three tools that offer: detailed organization of specific gene expression patterns (Expression Waves) during the differentiation process (bottom left); animation of KEGG pathways organized by successive days of differentiation (Pathway Animations, bottom middle); and, a search engine to obtain the expression of any transcript or groups of transcripts in the Affymetrix 430 v. 2 arrays during the ES cell differentiation process (bottom right).

Heatmaps of the 50 concise clusters for All Genes, Transcription Factors and ESTs according to their timing of induction or suppression during the normal ES cell differentiation process.

Expression profiles of the 19 Wnt genes during ES cell differentiation with the corresponding Affymetrix IDs using the ExpressView feature.

The links between the many genes involved in the maintenance of pluripotency and the regulation of ES cell differentiation programs are not well characterized.

The FunGenES database provides such a template with a number of tools including Animation of KEGG Pathways, Expression Waves, Time Series, Specific Gene Classes, such as ESTs and transcription factors, and searches for the expression pattern of any gene or transcript during ES cell differentiation using standard gene names and IDs.

These include: a) Global Clusters that consist of a small, tight subset of genes that are co-expressed under the entire spectrum of experimental conditions; b) Time Series of gene expression profiles during successive days of standard ES cell differentiation; c) Specific Gene Classes based on hierarchical clustering of transcriptional factors and ESTs; d) Expression Waves of genes with characteristic expression profiles during ES cell differentiation, juxtaposed to waves of genes that behave in the exact opposite way; e) Pathway Animations that illustrate dynamic changes in the components of individual KEGG signaling and metabolic pathways viewed in time - related manner; and, f) Search Engines to display the expression pattern of any transcript, or groups of transcripts, during the course of ES cell differentiation, or to query the association of candidate genes with various FunGenES database clusters.

For example, clusters containing genes that are upregulated during the course of ES cell differentiation (Table 3) include in order of time of expression: cluster 30 that represents genes which take part in the formation of the three embryonic germ layers during gastrulation, i.e., Goosecoid, Cerberus like 1 homolog, Wnt3, Mesp1, Mixl1, mEomes and Even - skipped 1; cluster 15 containing molecular regulators of early mesoderm development including Bmp2, Bmp5, Msx1, Msx2, Cripto, Tbx20, Hey2, Smad6, Vegfr2 (Kdr), Foxf1 and Hand1; cluster 20, which comprises regulatory and structural genes linked to hemopoiesis such as Gata1, Nfe2, Klf1, Tie1, hemoglobins (Hba - x, Hbb - b1) and Glycophorin A; cluster 12, which is rich in genes involved in cardiac development, e.g., Mef2c, Myl4, cardiac Troponin T2, Tropomodulin 1, myosin binding protein C, Bves, Angiopoietin 1 and Angiopoietin 2; and, cluster 4, which consists mostly of genes associated with neuronal development and differentiation, for example, Neurog1, Neurog2, Olig2, Nkx6.1, Neurod4, Pou3f2, Pou3f4, Cacna2d3, Cacng4, Kcnq2 and EphA5.

A. Partial snap shot of the «Expression Waves» window that depicts detailed specific expression patterns of genes during consecutive days of ES cell differentiation.

Moreover, ES cell differentiation in vitro recapitulates events that take place during early embryonic development including the formation of the three germ layers of ectoderm, mesoderm and endoderm, and the emergence of endothelial, hematopoietic, cardiac, neuronal and hepatic or pancreatic cells [8], [9].

In addition to the visualization of expression profiles during ES cell differentiation, the search engine provides links to analyze the selected genes using many publicly available tools and resources.

The notion that a Nanog positive, ICM - like population of high probability self - renewing cells is a developmental ground state is supported by the expansion of this state in the presence of a blockade on the major signalling pathways known to promote ES cell differentiation, the MAP kinase / ERK cascade and GSK3β [42], [50].

In this way embryo - derived stem cell lines and ES cell differentiation may be providing access to potential «transition states,» required for lineage specification in vivo.

(A) Schematic of ES cell differentiation toward ADE.

A future aspect of our mouse work is directed towards use of ES cell differentiation in culture as a model for epigenetic decisions and stem cell manipulations.

Not exact matches

The first page of Larsen's Human Embryology states that, `... [W] e begin our description of the developing human with the formation and differentiation of the male and female sex cells or gametes [sperm and egg], which will unite at fertilisation to initiate the embryonic development of a new individual».

Previously, in the region that controls the function of the transcription factor that promotes differentiation from ES cells to a specific cell type, bivalent modifications of histones such as the accelerator and brake histone marks for transcription were thought to have coexisted.

Using ES cells developed at Kyoto University's Institute for Frontier Medical Sciences, the research group collected RNA and histones of each cell immediately after VEGF stimulation (0 h), before differentiation (6 h), during differentiation (12 — 24 h), and after differentiation (48 h).

NeuroStemcell is focused on the identification and systematic comparison of progenitor cell lines with the most favourable characteristics for mesDA and striatal GABAergic neuronal differentiation, generated either directly from human embryonic stem (ES) cells, from Neural Stem (NS) cells derived from ES cells or fetal brain, from induced Pluripotent Stem (iPS) cells or from in vitro short - term expanded neural progenitors from ventral midbrain grown as neurospheres (VMN, Ventral Midbrain Neurospheres) 4, and perform rigorous and systematic testing of the most prominent candidate cells in appropriate animals models.

Here, Kate presents her work on that show that culture of human ES cells on human recombinant laminin - 521 and laminin - 111 substrates significantly improve hepatocyte differentiation, maturation, function and stabilization of phenotype compared to Matrigel cultured cells.

ES cells neural differentiation qualifies the role of Wnt / β - catenin signals in human telencephalic specification and regionalization

The collection of protocols includes the isolation and maintenance of stem cells from various species using «conventional» and novel methods, such as derivation of ES cells from single blastomeres, differentiation of stem cells into specific tissue types, isolation and maintenance of somatic stem cells, stem cell - specific techniques and approaches to tissue engineering using stem cell derivatives.

VASA expression increased during the differentiation of monkey ES cells, indicating that these cells have the ability to differentiate into a germ cell lineage in vitro.

To obtain further information on germ cell differentiation from primate ES cells, this study examined the ability of cynomolgus monkey (Macaca fascicularis) ES cells to differentiate into germ cells in vitro.

Thus while the majority of the V + population existing in ES cell cultures are indistinguishable from undifferentiated ES cells, we also observe differentiated cells expressing high levels of the Venus transgene (arrows in Figure 2B) that resemble the high - level Venus expressors generated in response to differentiation and that probably represent spontaneous PrEn differentiation.

Therefore, it is very important to develop a suitable protocol to induce in vitro germ cell differentiation from monkey ES cells before non-human primate ES cells can be used as a model for in vitro differentiated germ cells.

However, it remains unclear whether primate ES cells including those from humans can undergo gametogenesis through meiosis in vitro, although immature germ cell differentiation from primate ES cells has been reported [5], [6], [7].

Among the early germ cell markers examined, VASA is a candidate gene for detecting pre-meiotic germ cell differentiation from monkey ES cells, because its expression is detected earlier in the primordial stage of germ cell development in comparison to that of PIWI family genes in vivo in mice and humans [11], [36]--[38], [49].

Elevated levels of Nanog are also associated with a reduced probability of differentiation leading to the suggestion that ES cells exist in equilibrium between a stable self - renewing, ICM - like state referred to as the «ground state» and a transient metastable intermediate that is both able to revert to the self - renewing state or proceed into differentiation [8], [11], [47].

The current findings could provide important clues to determine the culture conditions for promoting the differentiation of primate ES cells into mature gametes, and to understand molecular mechanisms of primate gametogenesis including the timing of germ cell induction, the regulation of germ cell gene expression, and the response to growth factors for germ cell differentiation.

Taken together our data support a model in which ES cell culture has trapped a set of interconvertible cell states reminiscent of the early stages in blastocyst differentiation that may exist only transiently in the early embryo.

In humans, germ cell differentiation from ES cells via spontaneous EB formation, and EB formation with recombinant human bone morphogenetic proteins (BMPs) has been reported [5], [6].

In monkeys, methods for inducing germ cell differentiation from ES cells have not been reported except spontaneous germ cell differentiation by EB formation [7].

ES cell cultures also express low levels of Gata4 and Gata6, suggesting the presence of either background levels of PrEn gene expression or basal levels of PrEn differentiation [25], [27].

Previous studies demonstrated the VASA expression to increase with germ cell differentiation from mouse and human ES cells by co-culturing with BMP4 - producing cells [57] and the addition of recombinant human BMP4 [6], respectively.

Several protocols for inducing germ cell differentiation from ES cells have been reported.

However, these germ cell marker genes are not appropriate for detecting germ cell differentiation from mouse and human ES cells because these genes are expressed in both ES cells and germ cells.

A combination of several germ cell markers will thus be necessary to detect germ cell differentiation from ES cells.

To explore the differentiation markers for detecting germ cells differentiated from ES cells, the expression of various germ cell marker genes was examined in tissues and ES cells of the cynomolgus monkey (Macaca fascicularis).

The pluripotent properties of ES cells can be demonstrated by in vitro differentiation or by reintroduction of these cells back into chimeric embryos by blastocyst injection or morula aggregation.

To further examine the differentiation of ES cells into a germ cell lineage, EBs were stained with anti-VASA antibodies.

The detection of this level of Venus expression in the presence of low levels of Hex mRNA suggests that this reporter is indeed extremely sensitive to the low levels of Hex transcript produced in the absence of activin, earlier in differentiation, and in undifferentiated ES cells.

The lack of any SCP3 expression in the current experiments might suggest that the germ cell differentiation from ES cells did not go through the meiosis via a completely normal process.

We show that the fraction of cells present within this state is influenced by factors that both promote and suppress primitive endoderm differentiation, but conditions that support ES cell self - renewal prevent their progression into differentiation and support an equilibrium between this state and at least one other that resembles the Nanog positive inner cell mass of the mammalian blastocysts.

Hierarchical clustering organized samples according to differentiation stages, with undifferentiated ES cells and early differentiation states at the left and progressively more differentiated states toward the right.