Human Cloning

On February 22, 1997, Dr. Ian Wilmut, the 52-year old embryologist astonished the world by announcing that he had created the first animal cloned from an adult-a lamb named Dolly. By scrapping a few cells from the udder of a 6-year-old ewe, then fusing them into a specially altered egg cell from another sheep, Dr. Wilmut and his colleagues at the Roslin Institute in Midlothian which is seven miles from Edinburgh, Scotland, have suddenly nudged open one of the most forbidden- and fascinating-doors of modern life. People have been plagued with the possibility of building humans for centuries, much before Mary Shelley wrote "Frankenstein" in 1818. Researchers never believed that it was possible to create an identical genetic copy of an adult animal. Dr. Wilmut "does not have a belief in God."

On March 14, 1997, President Clinton declared "the creation of life is a miracle that reaches beyond laboratory science" and he barred spending federal money on human cloning. He also urged a halt in private research until the ethical impact is better understood. Clinton asked the National Bioethics Advisory Commission a week before his announcement to review the ramifications cloning would have for humans and report back to him in 90 days. He imposed the restrictions of federal funds after learning that researchers in Oregon had cloned two rhesus monkeys- (the world's first cloned primates and the closest step yet to humans)_ from very early embryo cells-that is not the same as cloning the more sophisticated cells of an adult animal, or even a developing fetus. "Human cloning would have to raise deep concerns, given our most cherished concepts of faith and humanity," Clinton said. "Each human life is unique, born of a miracle that reaches beyond laboratory science. I believe we must respect this profound gift and resist the temptation to replicate ourselves. Science often moves faster than our ability to understand its implications. Any discovery that touches upon human creation is not simply a matter of scientific inquiry. It is a matter of morality and spirituality as well." 

Clinton asked private research workers-who are not covered by his directive-to voluntarily keep off at least until the National Bioethics Advisory Commission can study the matter. Others were afraid that a permanent ban could thwart vital research on how genes are turned on and off inside human cells, a key factor in finding a cure for cancer or some birth defects or unlock the secrets to diseases. Clinton, too, noted the difference cloning could make in agriculture, medical treatments or "helping to unlock the greatest secrets of the genetic code." But he did not want scientific progress to move so fast that new developments are not handled responsibly and that without ethical implications people will try to play God.  

History 

1938: Cloning conceived 

The idea of cloning had enticed scientists since 1938. When no one knew what genetic material was or consisted of, the first modern embryologist, Dr. Hans Spemann of Germany proposed what he called a "fantastical experiment" : taking the nucleus out of an egg cell and replacing it with a nucleus from another cell. In short, he suggested that scientists try to clone. 

1952: First cloning experiment with frogs 

The size of the eggs in the frogs are enormous compared with those of mammals, making them far easier to manipulate. Robert Briggs and T.J. King used a pipette to suck the nucleus from the cell of an advanced frog embryo and added it to a frog egg. It did not develop. 

1970: Another experiment yields better results 

John Gurdon who is now a faculty member at Cambridge University successfully cloned the frogs. Even though the frogs never reached adulthood (the eggs developed into tadpoles but died after they were ready to begin feeding), the technique was a landmark. He replaced the nucleus of a frog egg, one large cell, with that of another cell from another frog. He later showed that transplanted nuclei reverted to an embryonic state. 

1981: Cloning of mice 

Dr.Karl Illmense of the University of Geneva and Dr. Peter Hoppe of the Jackson Laboratory in Bar Harbor, Maine, claimed that they had transplanted the nuclei of mouse embryo cells into mouse eggs and produced three live mice that were clones of the embryos. Their mice were on the cover of the prestigious journal Science, and their research generated a lot of excitement. After a lengthy inquiry, it was discovered that Dr. Illmensee had faked his results. 

1982: Research delayed

Dr. James McGrath and Dr. Davor Solter, working at the Wistar Institute in Philadelphia, reported in Science journal that they could not repeat the mouse-cloning experiment and concluded that once mouse embryos have reached the two-cell stage they cannot be used for cloning. Other investigators confirmed their findings. 

1984: First embryo cloning of sheep

Steen Willadsen reported that he cloned a live lamb from immature sheep embryo cells. Others later reproduced his experiment using a variety of animals, including cattle, pigs, goats, rabbits, and rhesus monkeys.  

1994: Cloning of more advanced embryo cells 

Dr. Neal First of the University of Wisconsin at Madison, who has been Dr.Ian Wilmut's most constant competitor, cloned calves from embryos that have grown to at least 120 cells. 

1996: Foundation laid for cloning of adult sheep 

Dr. Ian Wilmut of Roslin Institute, Roslin, Midlothian in Scotland, United Kingdom repeated Dr. Neal First's experiment with sheep, however he put embryo cells into a resting state before transferring their nuclei to sheep eggs. The eggs developed into normal embryos and then into lambs. 

1997: World's first adult sheep are cloned 

Ian Wilmut, A.E. Schnieke, J. McWhir, A.J. Kind and K.H.S. Campbell reported that they had cloned a 6-year-old adult sheep from an udder (mammary) cell in the world's most prestigious scientific journal, Nature of 27 February 1997(Vol.385, pp.810-813).
 

TECHNIQUE OF CLONING: 

The source of DNA (cell nucleus). A mammary cell is removed from the udder of a 6-year-old sheep (ewe) and cultured in a solution that starves it of nutrients to stop its development. Cells are constantly copying their own DNA and dividing. Researchers had to stop the donor cell from replicating its DNA.
 

A donor sheep is injected with hormones to release eggs (source of host egg cell). The unfertilized egg's nucleus, and thus its DNA, is removed, eliminating all genetic characteristics of the egg donor. What is in the nucleus? The nucleus contain the chromosomes (27 pairs in sheep and 23 pairs in humans) consisting of proteins and DNA, the genetic material that makes each individual unique. 
 

The Cell and Egg are Fused and Activated 

The cell (mammary) which is the source of DNA is inserted inside the covering around the egg cell (of donor sheep).

An electrical charge is applied to the two cells causing their pores to open, and the contents of the mammary cell to ooze into the egg. The electrical charge also tricks the egg into believing that it has been fertilized so it starts to divide. Of the 277 cells that were fused only 30 began to develop. It begins to develop like a normal embryo. The cell begins to divide over and over again. Each cell is identical to the original. When the embryo reaches, or is about to reach, the blastocyst stage, and the cells form a hollow ball (blastocyst) before they begin to differentiate or specialize.
 

After 6 days, the tiny embryos (29 of them) are implanted into the surrogate mother sheep (more that one embryo was implanted into a single sheep). Using ultrasound scans the surrogate sheep were monitored to confirm the pregnancy and monitor the development of the fetus once a month in the beginning and every two weeks later on. Out of 29 implanted, only one sheep gave birth to a lamb, which is genetically identical to the cell-donor (6-year-old ewe). This was named Dolly in honor of country singer Dolly Parton, whose mammary cells, Dr. Wilmut said, are equally famous. Dolly was born on July 5, 1996 at 4 P.M. It was a normal birth, head and forelegs first. She weighed 6.6 kilograms or about 14.5 pounds, and she was healthy.

Cloning of Humans:

After this exciting news many people all over the world believed that the cloning of humans is coming. The ethical, moral and theological frameworks of our society will be drastically affected, challenged and, at times, perhaps even devalued. We need to shape the policies and politics that will govern this remarkable technology. 

People who favor the cloning of humans argue that the knowledge of nuclear physics lead to the creation of the atomic and hydrogen bombs and at the same time the application of radiation and radionuclides in industry, medicine, agriculture, animal husbandry, etc. brought enormous benefits to mankind. In the late 1980s the United States undertook the human genome project. Again moral and ethical implications were raised and subsided and the project is moving along. Baby Louise was born out of invitro fertilization. Did it destroy the humaneness? Artificial insemination was opposed in the beginning. Now the opposition has melted away.

The benefits to mankind of cloning and genetic engineering are immeasurable- the creation of farm animals engineered to