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Embryonic stem cells are formed on the fourth day of development. Like all cells of the body, embryonic stem cells contain a full set of 46 chromosomes, with all the genetic information needed by every cell of the body. However, unlike other cells, embryonic stem cells have not yet differentiated; i.e. they have not developed into bone, skin, organs or other types of tissue. Once a cell has differentiated, it can only grow into that particular type of cell, while a stem cell can take the form of any cell in the body.
The mechanism responsible for stem cell differentiation is not yet clear. Research has indicated that the key to cell differentiation is which genes are turned on and which are suppressed. There are chemical messengers in the body that act upon the chromosomes, indicating which genes should be transcribed and translated into proteins, and which should remain muted. Only the genes needed for the function of the cell are activated.
In an undifferentiated stem cell, many different types of genes are expressed. Most of these genes will be turned off once the cell has differentiated into its adult form. Whatever potential it had as an embryonic stem cell will be narrowed down drastically. Stem cells also have almost infinite capacity to divide; however, once they have differentiated they lose the immortality they once had.
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Like in the embryonic stem cells, a large portion of the potential that we are born with will never be used. Only a small fraction of our true capabilities are ever expresed. If we would make use of the full complement of our true "genetic material," our accomplishments would be stunning indeed.
One of the definitions of the ultimate Redemption is the "revelation of the Infinite light." In the time of the Redemption there will be a revelation of the infinite G-dly potential hidden within all of us, within all of creation. All this hidden, inactive goodness will be released suddenly; the evil, having completed its task, will vanish like smoke. This will express itself not only on a spiritual plane but also physically, as we will live forever.
As to what life will be like during that ultimate stage, this is something that we cannot even emagine. As our sages say, "No eye has seen it save for G-d." However, we have been assured by the Lubavitcher Rebbe that we are about to enter this era. We will merit the fulfillment of the prophecy: "Eye to eye they shall see when the Lord returns to Zion."
Prof. Yirmiyahu Branover is chairman of the Center of Magnetohydrodynamic Studies and Training at Ben-Gurion University.
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