Cloning

Cloning is known as creating a copy of living matter, such as a cell or organism. When copies are made through cloning, the identical genetic makeups are known as clones. Some organisms in nature reproduce by cloning. Many scientists try to use cloning techniques and ideas to help them find solutions that will help them advance in medicine, biological research, and industry.

Cloning at first was started by farmers. They would clone plants, by cutting a part of the root and letting it grow to make another plant. Some farmers also devised breeding techniques to reproduce plants with characteristics such as faster growth, larger seeds, or sweeter fruits. These cloning techniques still had there issues and problems to deal with. They were known to grow slow and unpredictable at times. Cloning techniques are also used on animals. Scientists generate genetically modified animals with new traits, having the ability to resist disease, and they use cloning techniques to reproduce these genetically modified animals. Some scientists hope to clone animals that are living in a population of endangered species.

Many organisms replicate themselves through the process of asexual reproduction. Genetic information is encoded and sent form generation to generation in DNA which is a coiled molecule organized into structures called chromosomes within cells. Segments along the length of a DNA molecule form genes. When it comes to asexual reproduction an organism would copy it self, and a new body would grow around one copy of the DNA to form an offspring that would be genetically identical to its parent. Organisms composed of just one cell such as bacteria, reproduce through a type of asexual reproduction that is called fission. What fission is, is that a cell duplicates its DNA to form two complete sets of DNA. This parent cell then divides to form two daughter cells. Then each daughter cell receives one set of DNA. The two newly formed daughter cells would be identically the same to each other and to the parent cell.

Scientists had first made cloned cells in the laboratory by letting a single divide into a population of genetically identical cell. In this process scientists put the original cell in a dish containing culture medium which is the nutrient needed to keep a cell alive. The cells natural process of mitosis then would produce genetically identical offspring. Later on scientists also developed easier was of cloning which involved using animal embryos. Every cell in an animal came from a fertilized egg. The fertilized egg divides to form an embryo, and each cell in the embryo would have the same genetic makeup.

Since the first cloning of a animal named Dolly the sheep in 1996, scientists have cloned a wide variety of mammals from adult cells, including cows, goats, pigs, cats, and rabbits. They have achieved a lot of remarkable advances in animal cloning but drawbacks still remain to this day. Somatic cell nuclear transfer is inefficient; few cloned embryos survive through birth. Other problems that came from cloning were health problems that animals were facing. As Dolly the sheep was aging, they saw that she prematurely developed arthritis. Other experiments found that cloned mice suffered more illnesses and died at about half the age of a normal mouse. Dolly came from a cell taken from an udder of an adult Fin Dorsett sheep and an enucleated egg from a Scottech blackface ewe. Dolly's birth proved that adult cells could acquire the cloning potential of embryonic cells. It took the scientists 277 tries at somatic cell nuclear transfer to actually create Dolly. In July 1997 the people at the Roslin Institute announced the birth of Polly, the first genetically modified lamb. When they made Polly scientists had to insert fragments of DNA containing the human gene for blood clotting factor IX, used in the treatment of hemophilia into the cells of sheep's. The animal cells included the human DNA into there own genetic makeup. Scientists then were able to clone these cells to create Polly.

Even though there are a lot of problems that arise from cloning, scientists believe that animal cloning will hopefully one day advance agricultural practices and medicine, and even prevent the extinction of endangered animals. In an agriculture view point, cloned cattle could produce a higher amount of meat or milk. The pharmaceutical industry already uses cloned animals to produce drugs for human use. Cloned animals can also improve laboratory experiments. Researchers could create many genetically identical animals to reduce the variability in a sample population used in experiments, making it easier for scientists to evaluate diseases. Scientists could also clone a large number of animals that suffer from human diseases, such as arthritis, to study the disease's progression and potential treatments. Some cloned animals like sheep and pigs live for years, and scientists could use these animals to evaluate there long term response to drug treatments.

With cloning technology growing so fast it can bring some animal populations back from extinction. In 2001 scientists successfully cloned a gaur which is an endangered ox that lives in Southeast Asia. They inserted the genetic material from the skin cell of a dead male gaur into a cow's egg cell that had its nucleus removed. The resulting embryo would then be implanted into a female cow which would be the surrogate mother. The gaur calf died two days after birth from a bacterial infection which supposedly wasn't related to the cloning process. Scientists may one day be able to clone extinct animals. The last wild Spanish ibex which is also known as bucardo, a mountain goat native to the Pyrenees mountain range of northern Spain, died in 2000. Spanish scientists got to preserve some of its cells, which they hope they can later on use the cells to create a cloned embryo and then implant the embryo into a more common type of goat with a genetic makeup similar to that of a the Spanish ibex. In order to actually clone endangered and extinct animals they need cells that contain an intact nucleus with an undamaged DNA. They would also need to implant a cloned embryo into a surrogate mother from a closely related species. These requirements prevent scientists from cloning cells from the fossilized remains of dinosaurs and other long extinct animals.

If scientists are able to clone animals then cloning humans shouldn't be much different. In 1998 a South Korean research team said they were able to cone a human embryo through somatic cell nuclear transfer, but the embryo only survived to four cells. In 2001