The cloning of animals will be beneficial to human beings inthe near future. Experiments in cloning animals started in the early nine-teen-fifties. Over the next forty years, scientists were only able to clone animals from very young embryonic cells. When these scientists tried to use older cells for cloning, they did not get normal results. This led many scientists to believe that animals could not be cloned from adult cells. (Pennisi, 1997) However, this all changed in the Summer of 1995 with the birth oftwo lambs, Megan and Morag, at the Roslin Institute in Scotland.
The birth of these two lambs led to one of the most astounding breakthroughs in scientific history, the birth of a lamb named Dolly. Megan and Morag were two lambs carried to term by a surrogate mother. However, Megan and Morag were not produced by normal biological methods. Their genetic code came from the cells of a nine-day-year old embryo. Thus, Megan and Morag were genetic copies, or clones of this embryo. The key to this cloning was a process called nuclear transfer.
This process requires the use oftwo cells, the donor cell and the recipient cell. The recipient cell is usually an unfertilized egg. Researchers at the RoslinInstitute used microscopic instruments, like a micro pipette, to extract all of the chromosomes from the recipient cell. The recipient cell was then fused to the donor cell and placed into the surrogate mother.
The birth of Megan and Morag was a tremendous breakthrough because these scientists proved that older cells could be genetically reprogrammed to act like cells in an early embryonic stage. (Wilmot, 1998) The research that went into the development of Megan and Morag eventually led to the birth of the first mammal cloned from an adult mammal. To accomplish this, the research team at the Roslininstitute used cells removed from a six-year-old ewe s udder. These cells were then deprived of any nutrition, which forced the genes to become inactive. Th researchers did this because they wanted the cell-cycle stage of the recipient to be the same as the donor s cell-cycle stage. The researchers then performed the nuclear transfer and tried to stimulate the inactivated genes to start to develop into a new lamb.
Only one out of two-hundred and seventy-seven eggs produced a healthy lamb, which was named Dolly. The difference between the cloning of Megan and Morag and thecloning of Dolly is that Megan and Morag were cloned from a young cell, while Dolly was cloned from an adult cell. This was the first time that an animal had ever been cloned from and adult cell. Thus, proving the theory, that an animal could not be cloned froman adult cell, was wrong. (Pennisi, 1997) The birth of Dolly, which was in February of 1997, has led to increased research and development into the cloning of animals. On Wednesday, the eighth, the Washington Post printed an article which stated that Japanese researchers had cloned eight calves from one adult cow.
This achievement is a big improvement over Dolly because eight calves were born from ten attempts, while Dolly waste only successful birth out of two-hundred and seventy-seven eggs. These calves were cloned from cells taken form a cow so varies and fallopian tubes. The cells that were taken from the fallopian tubes were a kind of cell that had never been used for cloning before. The cloning of these calves is big news because cows are one of the most commercially important animals. Thecloning of cows will allow for an easier way of expanding the herds and developing cows to produce more and better milk. (Weiss, 1998) The cloning of animals will be a very important part of our future, especially the animals that we rely on.
One way that cloning animals will be important to us is that only the best of each type of animal that we rely on, like cows that produce quality beef and milk, would be cloned. Thus reducing the possibility of disease carried in these animals, like mad cow disease. A second way that cloning would be beneficial to us, is that once scientists figure out how to add other beneficial characteristics to a donor cell, then animals could be genetically engineered to be resistant to all forms of disease. These animals could also be engineered tobe able to donate organs to humans. In the case of cows, they could be developed to produce medicines in their milk that would be beneficial to humans. Researchers at the Roslin institute are already working on cloning sheep with a gene that would allow the sheep to produce milk that contains a beneficial protein that hemophiliacs use to aid in allowing their blood to clot.
(Pennisi, 1997).