What are some examples of cell survival signals?
What are some examples of cell death signals?
Stem cells Cloning: read therapeutic (SCNT) vs. reproductive cloning
Every cell undergoes the process of programmed cell death,what we call as apoptosis. Several factors like pro-apoptotic and antiapoptotic are responsible for apoptosis.
Now, for cell survival it is necessary to inhibit the pro.-apoptotic signals or activation of anti-apoptotic signal mechanism. Wheras, activation of pro-apoptotic signalls are necssary for apoptosis to takes place. Thus cell survival signals includes Bcl-Xl and Bcl-2, which are member of Bcl-2 family. Wheras, when apoptosis or cell death is active, then pro-apoptotic members like BAX, BID, BAK, or BAD also get activated.
Somatic cell Nuclear transfer or therapeutic cloning- in this method two cells are required. One will be host cell and the second will be donar cell. In host cell, which is normally a egg cell, the nucleus will be removed. Next, nucleus from donar cell, which is somatic cells are transfered to the egg cell. The embryo which is formed will be used to generate stem cells, where the cells will be a exact genetic match to the donar cell. Whereas, in reproductive cloning, the embryo which is formed by replacing the host nucleus with donar cell nuclues will be placed into the uterus of the host cell and will continue to grow until the full development of the animal. Thus, in therapeutic cloning the embryo will be used as a source of stem cells in the laboratories for therapeutic purposes but in reproductive cloning, the embryo will be allowed to grow as mature individiual.