By Avigayil Kadesh
Israeli researchers are paving the way for a science-fiction-sounding reality where one day scientists could generate human eggs from amniotic membrane cells.
Women wishing to become pregnant in the absence of natural ovulation can find new hope in an article published in the journal Reproductive Biology and Endocrinology, in which the researchers describe their revolutionary experiments using cells from the placenta, the afterbirth normally discarded after a baby is born.
Ayelet Evron, a doctoral student at theTechnion-Israel Institute of Technology, and her mentor, Dr. Eliezer Shalev, dean of the Technion medical school and a practicing obstetrician/gynecologist at the Emek Medical Center in Afula, are conducting experiments with Dr. Shulamit Goldman of Emek’s Laboratory for Research in Reproductive Sciences.
Mimicking adolescence
Amniotic membrane cells appear about eight days after conception to preserve the plasticity of an embryo's cells before the cells differentiate into different parts of the body.
These same cells, Evron and Shalev found, are capable of differentiating into ones that express the properties of “germ cells,” which produce eggs in a woman’s ovaries.
Under normal circumstances, germ cells remain undifferentiated until girls reach puberty. They turn into eggs through the chemical action of proteins or hormones that begin to surround the ovaries in adolescence. If the conditions of adolescence could be replicated, in theory it should be possible to make the differentiated amniotic cells act like germ cells and become human eggs.
“Germ cell development has been difficult to study in humans because important early events occur after implantation [of the fertilized egg],” said Shalev.
Possibilities for pregnancy
Dr. Shalev stressed that the process he and Evron envision works in principle, though it is too early to tell if it will succeed in practice. Currently, women whose ovaries don’t produce eggs, because of premature menopause or some other condition, cannot get pregnant unless they use eggs surgically harvested from another woman.
However, if the Israeli research is developed to the point where it is indeed possible to produce egg cells from the amniotic sac, “women who do not produce healthy ova -- or any at all -- could use them to become pregnant,” Shalev added.
This would be a significant breakthrough.