Sentences with phrase «embryonic cell layers»

But it seemed unlikely, because the body coverings were thought to grow differently: Feathers and hair develop from specialized plates of thickened ectoderm — an embryonic cell layer — called anatomical placodes, structures not seen in reptiles.

Not exact matches

2 - The embryonic stage: Basic organs begin to emerge from the cell layers.

During embryonic development, undifferentiated stem cells accumulate methyl groups and other epigenetic marks that funnel them into one of the three germ layers, each of which gives rise to a different set of adult tissues.

Scientists were even more stunned in July 2002 when researchers led by stem cell biologist Catherine Verfaillie at the University of Minnesota reported that bone marrow — derived cells they had injected into young embryos contributed to all three embryonic layers, just as embryonic stem cells would do.

Embryonic development in mammals begins with the division of the fertilized egg, which is then followed by several further rounds of division to form the blastocyst, a sphere of cells made up of two layers of cells surrounding a fluid - filled cavity.

When transplanted to the subretinal space of mice lacking functional photoreceptors, human embryonic stem cells directed toward a retinal lineage integrate into the outer nuclear layer, express photoreceptor markers, and restore a light response as determined by the electroretinogram (ERG)[5].

Figure 1: The blastocyst is a hollow sphere made of approximately 150 cells and contains three distinct areas: the trophoblast, which is the surrounding outer layer that contains the trophoblast stem cells and later becomes the placenta, the blastocoel, which is a fluid - filled cavity within the blastocyst, and the inner cell mass, also known as the embryoblast, which can become the embryo proper, or fetus, and is where human embryonic stem cells are isolated from.

The grand architecture of the human cortex, with its hundreds of distinct cell types, begins as a uniform layer of neural stem cells and builds itself from the inside out during several months of embryonic development.

Henk Stunnenberg, leader of one of the research groups that carried out the study and coordinator of both Heroic and the recently started High Impact Project BLUEPRINT, said: «The epigenetic make - up - a layer of regulatory instructions on top of the genome - of the pure embryonic stem cells shows remarkable and unexpected features, in particular with respect to developmental genes.

Moreover, the iPS cells can spontaneously differentiate or be induced into various cell types of three embryonic germ layers in vitro and in vivo when they are injected into immunodeficient mice for teratoma formation.

In one approach, a one - cell - thick layer of RPE cells derived from human embryonic stem cells or adult RPE stem cells is placed on a material that allows nutrients and waste materials to pass through and is implanted in the eye.

With current methodologies, mouse embryonic fibroblast (MEF) cells have been used as a feeder layer to derive both mouse and human iPS cells.

In suspension culture, they formed embryoid bodies (EBs), which contained various cell types originating from three embryonic germ layers.

For those species, the human cells could be added at a later stage of embryonic development and would require an extra layer of scrutiny by a special NIH committee.

Additionally, single - cell derived bovine iPSCs formed embryoid bodies and teratomas that all subsequently gave rise to differentiated cells from all three embryonic germ layers.

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].

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.

Commitment in embryonic stem cells is often depicted as a binary choice between alternate cell states, pluripotency and specification to a particular germ layer or extraembryonic lineage.