Dr. Jones: What if anyone, man or woman, young or old, could make eggs out of skin cells and have an unlimited and easy to access source of baby making? How could that happen? This is Dr. Kirtly Jones from Obstetrics and Gynecology at 麻豆学生精品版care and this is In-Vitro Gametogenesis on The Scope.
Announcer: Covering all aspects of women's health, this is the Seven Domains of Women's Health with Dr. Kirtly Jones on The Scope.
Dr. Jones: The holy grail of regenerative medicine is to be able to make organs or tissues that need replacing, think cartilage in your sore knees, from cells that are yours and are easy to get. In the process of human development, cells that are very early in the embryo are called totipotent. That means they can turn into any cell in the body. The time that cells are totipotent in normal human development is quite short, maybe just a few days after fertilization. After that, cells start going down a pathway of development and cannot go back. Cells become pluripotent meaning they can turn into a number of cell types of one type, perhaps the cells of the tissues of internal organs but they cannot make eggs or sperms anymore.
When you hear the word stem cells or stem cell research, it refers to cells that are not completely developed or differentiated into skin or hair or other tissues but can be turned on in natural development to replace cells in certain tissues when those cells die. Over the past 30 years, a lot of research has been focused on harvesting and growing stem cells to be used in treatment of disease. The poster child is bone marrow transplantation for the development of blood cancers like leukemia. This treatment is highly effective in using blood stem cells from cord blood or an adult's bone marrow or maybe someone's own blood stem cells to replace the diseased blood cells.
Okay. Although it isn't prime time or covered by insurance, some clinics are harvesting stem cells from tissues and injecting them into knees that have had the cartilage wear down in hopes that these stem cells will decide to make cartilage when they find themselves in the right place.
So what about eggs? What if you could take skin cells, just a little bit of skin tissue, and harvest the stem cells that help replace skin cells, turn back the developmental clock to make early egg cells? In the ovary, there is a supply of egg cells that are being very early in development and can grow and mature to ovulate each month when a girl goes through puberty until they run out at menopause.
Recently, a Japanese research group did just that in mice. They took mouse skin cells, turned back the developmental clock and made early egg cells, let the eggs develop, added sperm, made embryos, put them in a mouse, and made mouse babies. Okay. This is where what is called the yuck factor comes in. The yuck factor is when someone hears about a new development in science or medicine and it tweaks their emotional or moral sense. Think face transplants. There is a little yuck factor there. Sometimes the yuck factor calms down with a little more understanding and experience.
The possibility of making animals or humans this way to have a source of gamete cells, meaning eggs and sperm, available to men or women, young or old, sort of tweaks the yuck factor in some folks. Many people experience the yuck factor when the first in-vitro fertilization baby was born or when human egg donation became a way for postmenopausal women to bear children or when human embryo banks were established with frozen embryos to be chosen, bought, and shipped to be transferred into a surrogate uterus. So here we have the yuck factor with the process of growing eggs or sperm in the lab from skin cells or other cells. This is called in vitro gametogenesis, generating gametes in the test tube.
There are some very interesting scientific questions about early development of eggs and sperms and embryos that could be answered using this technology. And people who'd run out of eggs or sperm in the case of women, may be menopause, in the case of men or women, may be chemotherapy, might have their source of eggs and sperm with their own DNA. If a woman and her female partner wanted to make a baby with DNA from both of them, they could use this technology. Of course, although the mice were made in the lab with in vitro gametogenesis this year, that doesn't mean the technology will be available to make human embryos tomorrow.
Like cloning, making an embryo from a skin cell, think Dolly the Sheep, it never really took off for humans, and there are still a lot of questions about the safety for the newborn child to be, but it may be right around the corner and what will we do about that? Stay tuned and thanks for joining us on The Scope.
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