Embryonic Stem Cells
by Junying Yu* and James A. Thomson**
Human embryonic stem (ES) cells capture the imagination because they are immortal and have an almost unlimited developmental potential (Fig. 1.1: How hESCs are derived). After many months of growth in culture dishes, these remarkable cells maintain the ability to form cells ranging from muscle to nerve to blood—potentially any cell type that makes up the body. The proliferative and developmental potential of human ES cells promises an essentially unlimited supply of specific cell types for basic research and for transplantation therapies for diseases ranging from heart disease to Parkinson's disease to leukemia. Here we discuss the origin and properties of human ES cells, their implications for basic research and human medicine, and recent research progress since August 2001, when President George W. Bush allowed federal funding of this research for the first time. A previous report discussed progress prior to June 17, 2001 (/info/scireport/.)
“How human embryonic stem cells are derived.“ In the upper left hand corner, the human egg is fertilized by a sperm in a test tube (in vitro); this is called day 0. The next drawing shows day 3, when the embryo consists of large round cells, labeled as “totipotent (link to term in glossary) cells.“ At day 5, the drawing shows a blastocyst (link to term in glossary), which consists of an outer layer called the trophectoderm , a large fluid-filled cavity called the blastocoel, and a small mass of cells at one pole called the “inner “cell mass.“ The inner cell mass is removed and is then shown being grown in a tissue culture dish, where the cells are labeled “cultured pluripotent stem cells.â€
https://stemcells.nih.gov/info/Regenerative_Medicine/2006Chapter1.htm
