Sometimes it's enough to have chemistry
by Tamara Traubman
Recently, researchers succeeded in extracting stem cells from monkey embryos, created without the use of sperm. The young embryos the researchers used cannot go on to develop into babies, so the achievement may resolve the political controversy fueled by human embryonic stem cell research. The stem cells extracted from embryos have an unusual ability to transform into any of the body's tissues, so biologists hope that it will be possible to use them to repair damaged tissues in the body.
Scientists have recently taken some steps towards developing alternative sources of stem cell production. The new source of cells is unfertilized eggs taken from apiaries. The embryos were created in a process known as "virgin reproduction". Unlike the normal process in which a sperm fertilizes the egg, in vitro fertilization makes the egg "think" it was fertilized with chemicals. The researchers waited for the embryos they created using this method to reach the age of 5-4 days, when the stem cells appear, and then harvested the cells from them.
The research was done in the laboratories of the American biotechnology company "Technology," Advanced Cell and its findings are published in the latest issue of the scientific journal." "Science, the same company announced at the end of last year that it tried to clone a human embryo.
In the same report, the society's scientists discovered that they had also tried to create embryos through virgin reproduction. The embryos did reach the age of five days, but apparently did not contain stem cells. However, in the months that have passed since then, researchers have continued experiments with human eggs. The lead author of the current study, Dr. Jose Sibley, told the "New York Times" newspaper, that "bottom line, we are very confident that we will be able to repeat the results (in human eggs, XNUMX)".
To date, the only embryonic stem cells that scientists have studied have been produced from embryos produced in fertility clinics, and which were left unused after the couple succeeded in having a baby. Since during the production of the cells the embryo is destroyed, religious and conservative factors strongly oppose the research in embryonic stem cells.
Opponents highlight other sources that are currently being researched as a possible alternative to the use of embryonic stem cells. When US President George Bush approved research on embryonic stem cells under severe restrictions a year ago, he cited adult stem cells as a "promising source" for creating tissues that will help regenerate damaged tissues in the body. Adult stem cells are found in the body of an adult person, so their use does not involve ethical problems from the point of view of the conservatives.
Similar to embryonic stem cells, adult stem cells are also cells that have not yet been determined exactly what type of cell they will become. Until recently, biologists were convinced that unlike embryonic cells, which can turn into any of the body's cell types, adult stem cells are more limited and can only turn into a cell that belongs to the tissue of origin in which they are found.
However, in recent years scientists have proven that adult stem cells taken from mice can turn into a very wide variety of cells. And in the month of January, Dr. Kathryn Warpeili from the University of Minnesota claimed that she possessed mature human stem cells that managed to turn into brain, liver, skin and many other types of cells.
Dr. Sibley's cells also developed into a variety of cell types, including heart cells and brain cells of the type destroyed in Parkinson's patients. To create the monkey embryos, he and his colleagues used the virgin reproduction method. Normally, sperm is the stimulus that causes the egg to begin developing into an embryo. On the other hand, in virgin reproduction the stimulation is done by exposing the egg to chemicals. A normal egg contains two sets of chromosomes. When a sperm fertilizes it, it gets rid of one, and receives in its place a second set of chromosomes from the sperm. In betulin reproduction, the chemicals cause the egg to use its two sets of chromosomes, and begin development.
However, on some of the genes that the parents bequeath to the fetus, there are chemicals that determine which of the genes will be contributed to the fetus from the woman's side and from the man's side.
"An embryo created from genes implanted only by the woman will not be able to develop properly, at least according to experiments on mice and other animals," said Dr. Benjamin Raubinoff from the Hadassah Ein-Karem Hospital. Therefore, it is possible that the religious-Christian establishment and the opponents of abortion will not see the destruction of a human embryo developed in virgin reproduction as a deprivation of life, which could have developed from a normal embryo.
But according to Raubinoff, although the use of embryos created through virgin reproduction may soften the ethical controversy, it is still unclear whether the cells produced could actually have a medical use. "Although the stem cells succeeded in turning into adult cells," he said, "the researchers must prove that such cells - whose genetic material originates from the mother only and not from a combination of the mother and the father - do not have the properties of cancer cells.
I think there is a good chance that cells from such a source will develop into normal tissues that can be used for transplantation, but this needs to be proven."
In the picture: the eggs of the eggs begin to develop into embryos
