Reproductive cloning would diminish the sense of uniqueness of an individual. It would violate deeply and widely held convictions concerning human individuality and freedom, and could lead to a devaluation of clones in comparison with non-clones.
Cloned children would unavoidably be raised "in the shadow" of their nuclear donor, in a way that would strongly tend to constrain individual psychological and social development.
Reproductive cloning is inherently unsafe. The technique could not be developed in humans without putting the physical safety of the clones and the women who bear them at grave risk. If reproductive cloning is permitted to happen and becomes accepted, it is difficult to see how any other dangerous applications of genetic engineering technology could be proscribed. This will be true only if we allow it to be true. There is no reason that individuals and society can't learn to embrace human clones as just one more element of human diversity and creativity.
The problem of "expectations" is hardly unique to cloned children. Most parents learn to communicate their expectations about their children in a moderate and ultimately positive way. Every medical technology carries with it a degree of risk. Cloning techniques will eventually be perfected in mammals and will then be suitable for human trials. Reproductive cloning can provide genetically related children for people who cannot be helped by other fertility treatments i. Reproductive cloning would allow lesbians to have a child without having to use donor sperm, and gay men to have a child that does not have genes derived from an egg donor though, of course, a surrogate would have to carry the pregnancy.
Reproductive cloning could allow parents of a child who has died to seek redress for their loss. Three years ago, CheMyong Jay Ko received a call from a distraught older man. He had called Ko with a simple but urgent question: Would it be possible to clone his beloved pet?
After all, he has studied genetics and cloning for genetics and physiology for more than 20 years. So he had a ready answer: yes, cloning was possible. Naturally, there was a catch. Cloning requires cells that contain enough intact DNA. But animal tissue begins to degrade soon after death as bacteria start to gnaw away at newly defenseless cells. Back in the lab, he and his team revived and cultured some of the cells from their samples.
Theoretically, they now had the material to create a genetic double of the dead dog. In practice, of course, things were about to get a lot more complicated. Scientists have known that mammal cloning was feasible since , when Dolly the sheep was born.
Since then, they quickly moved on to trying to other animals: mice, cattle, pigs, goats, rabbits, cats. But due to differences in the canine reproductive process, dogs proved a trickier challenge. Myth: Meat from clones is already in the food supply. Myth: Cloning can cure diseases in livestock. Myth: Scientists can bring back extinct species by cloning them. In fact, we eat fruit from plant clones all the time, in the form of bananas and grafted fruits.
Some animals can reproduce themselves by vegetative propagation, including starfish and other relatively simple sea creatures. Amphibians such as frogs first underwent cloning in the s. Identical twin mammals can be thought of as naturally occurring clones, but producing clones of mammals in the laboratory is relatively new. Using cells from animal embryos to make clones has been has been around since the early s, but the first animal cloned from a cell from an adult animal was Dolly the sheep, who was born in Absolutely not.
Despite science fiction books and movies, clones are born just like any other animal. That embryo is implanted into the uterus of a surrogate dam a livestock term that breeders use to refer to the female parent of an animal to grow just as if it came from embryo transfer or in vitro fertilization.
No, not at all. A clone produces offspring by sexual reproduction just like any other animal. A farmer or breeder can use natural mating or any other assisted reproductive technology, such as artificial insemination or in vitro fertilization to breed clones, just as they do for other farm animals. The offspring are not clones, and are the same as any other sexually-reproduced animals.
They have the same genes, but look a little different. A bill that would ban the procedure languished in Congress this summer. Althought Wicker is pro-therapeutic cloning, he was skeptical that the cells could be safe for one use but not another.
Berg explained that when an embryo develops into a blastocyst about cells , it contains embryonic stem cells that would be used for therapy. Researchers predict they could be used without the complications of foreign donor tissue, since they would essentially be take from a clone of the patient. When combined with normal cells, Berg and Jaenisch said there's a good chance these therapeutic cells will function fine. Jaenisch said that although he believes there should be more research, developmental errors would not be an issue because the cells would not contribute to the development of a whole organism.
0コメント