About Embryonic stem cell research?

Questions:


1) What are embryonic stem cells and where are they found?


2) What is the source of embryonic stem cells used in research?


3) Why are embryonic stem cells considered so valuable for scientific/medical research?


4) If they are so valuable in research and offer treatments for presently incurable physical and


genetic conditions what is the controversy all about?


5) What other types of stem cells are there and are they useful in research?

About Embryonic stem cell research?
1) what are stem cells and why are they important?





Stem cells have two important characteristics that distinguish them from other types of cells. First, they are unspecialized cells that renew themselves for long periods through cell division. The second is that under certain physiologic or experimental conditions, they can be induced to become cells with special functions such as the beating cells of the heart muscle or the insulin-producing cells of the pancreas.





2) Source


A. What stages of early embryonic development are important for generating embryonic stem cells?


Embryonic stem cells, as their name suggests, are derived from embryos. Specifically, embryonic stem cells are derived from embryos that develop from eggs that have been fertilized in vitro—in an in vitro fertilization clinic—and then donated for research purposes with informed consent of the donors. They are not derived from eggs fertilized in a woman's body. The embryos from which human embryonic stem cells are derived are typically four or five days old and are a hollow microscopic ball of cells called the blastocyst. The blastocyst includes three structures: the trophoblast, which is the layer of cells that surrounds the blastocyst; the blastocoel, which is the hollow cavity inside the blastocyst; and the inner cell mass, which is a group of approximately 30 cells at one end of the blastocoel.





3) importance - they can be induced to become cells with special functions such as the beating cells of the heart muscle or the insulin-producing cells of the pancreas.





4) controversy - it seems unethical since you are taking egg cells, which are potential embryos.





5) stem cells from bone marrows i think. yes they are useful and basically function the same way as embryonic stem cells.
Reply:Good answer above. Stem cells are capable of differentiating into any cell type of the species.


Since they're taken from embryos, it's more than an egg involved; it's an embryo. That, to many, is a human being.


Methods have been found to use not only stem cells from cord blood, but also to switch more differentiated cells into pluripotent cells very much like stem cells, perhaps obviating the need to destroy embryos. Almost all stem cell research is still in such an early stage that it's hard to say what the impact of these developments might be. It could be that recent an future developments will remove the controversy.

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