ewheat
Joined: 17 Nov 2012 Posts: 10
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Posted: Sun Nov 18, 2012 6:37 pm Post subject: Embryonic stem cell |
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Embryonic stem cell
Embryonic stem cell lines are cultures of cells derived from the epiblast tissue of the inner cell mass (ICM) of a blastocyst or earlier morula stage embryos. A blastocyst is an early stage embryo—approximately four to five days old in humans and consisting of 50–150 cells. ES cells are pluripotent and give rise during development to all derivatives of the three primary germ layers: ectoderm, endoderm and mesoderm. In other words, they can develop into each of the more than 200 cell types of the adult body when given sufficient and necessary stimulation for a specific cell type. They do not contribute to the extra-embryonic membranes or the placenta.
Nearly all research to date has taken place using mouse embryonic stem cells or human embryonic stem cells . Both have the essential stem cell characteristics, yet they require very different environments in order to maintain an undifferentiated state. Mouse cells are grown on a layer of gelatin and require the presence of Leukemia Inhibitory Factor (LIF). Human ES cells are grown on a feeder layer of mouse embryonic fibroblasts and require the presence of basic Fibroblas Growth Factor Without optimal culture conditions or genetic manipulation, embryonic stem cells will rapidly differentiate. _________________ drug coupons |
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