In my report I will be discussing cloning, what it is, how it is done and the different types of cloning. I will also discuss the experiments that are being currently done and the experiments that were done in the past. I will give views that people have about cloning such as people's ethical views, religious views and the political views. Finally I will talk about the pros and cons of cloning and my personal opinion on cloning.
Clone is a term that originated from ????, which in Greek is twig or branch referring to the process whereby a new plant can be created from a twig. In biology cloning is the production of population of genetically-similar individuals that occurs when organisms reproduce asexually.(10) Organisms that reproduce would be bacteria, plants, insects, animals and humans, after the reproduction of the two same organisms they would create an offspring who would have some characteristics one organism and some characteristics of the other organism. But cloning in biotechnology is the process to create exact copies of DNA fragments, cells or organisms. The cloning of DNA fragments is known as molecular cloning and the cloning of cell is known as cell cloning. These type of cloning is not done asexually, instead these cloning are performed by scientists in labs and is known as biological engineering.(9)
Types of cloning
Currently there are a few types of cloning that is being done and being worked on to be improved to change the medical world. The most common type of cloning that is being done is Stem Cell. Stem cell treatments are a type of cell therapy that introduces new cells into damaged tissue in order to treat a disease or injury. (18) Another type of cloning is Somatic nuclear cloning, where the nucleus of a somatic cell is transferred into the cytoplasm of an enucleated oocyte, which is an egg without its nucleus to create a clone that is genetically identical to the organism from which the somatic cell nucleus was derived. A type cloning that is not done very much, but was used in the past is called xenotransplantation; it is the process of transferring an organ from one species to another.(14)
The process of somatic nuclear transfer is when a somatic cell is sent into the cytoplasm of a enucleated oocyte. After the somatic cell is sent it will eventually create a clone that is genetically identical to the organism which the somatic cell nucleus was derived from. The process of sending the somatic cell to enucleated oocyte can be done from a procedure called electro fusion. Electro fusion in when the jolt of electricity is used to force the specially treated somatic cell and enucleated oocyte to fuse to together.(16) After the electro fusion the enucleated oocyte become a chemeric oocyte, which is a fertile egg, and is then placed in a surrogate womb for embryonic development. For a human it would take none months for the result to be created and in the end it would be an exact biological copy of the organism which the somatic cell was first taken from.(13)
Somatic nuclear transfer was fist done over 40 years ago to a frog, but the procedures kept failing when it was tried on mammals. The first success in cell cloning was in 1996 when Dolly the sheep was first cloned by Professor Ian Wilmut and his Roslin Institute in Edinburgh, Scotland. After the large success of Dolly the sheep somatic cell cloning was done on cattle, goats, mice, pigs and chickens which is an astonishing accomplishment.(14) The large benefits of cloning animals are that it can be used for the production of therapeutic proteins of human compatible tissue organs. The production of therapeutic proteins would be accomplished by first creating a somatic cell nucleus, one that contains the gene having the desired therapeutic protein, then transferring this nucleus into the enucleated oocyte. This results in a trans-genetic animal clone.(12)
The gene for a human coagulation factor IX, missing in haemophiliacs, has been cloned into somatic sheep cells the generic controls for expression in sheep milk. The somatic cells were used to create somatic cell sheep clones that expressed the protein in their milk. Current treatment for haemophiliacs is primarily by purifying factor IX from human blood. This is problematic in that is expensive and has inherent disease risks (e.g. AIDS). Cloning proponents suggest that production of recombinant proteins in livestock milk may be cheaper and more easily regulated.(13)
Human-compatible organs and tissues can be created from a complicated cloning procedure involving either genetic engineering of animals, such as pigs, to destroy problematic transplantation antigens on animal organs, or by using embryonic stem cells to clone human organs. The process of transferring an organ from one species to another is called xenotransplantation. Stem Cells are pluripotent, which have the potential to develop as multiple cell types, cells that are derived from various tissues; embryonic tissue yields totiptent embryonic stem cells.
Most, if not all multi-cellular organs have stem cells in their body. Stem cells are characterized the ability they have to renew themselves by the process of mitotic cell division which seperates the cells into a wide range of special cell types. Due to findings by Canadian scientists Ernest A. McCulloch and James E research in the area of stem cells has grew.(4) Till in the 1960s. The two broad types of mammal type stem cells are: embryonic stem cells that are isolated from the inner cell mass and adult stem cells that are found in adult tissues. When an embryo is being developed the stem cells that arre fond inside it can seperate into different kind of the special type of embryonic tissues. Stem cells and progenitor cells in adult organs act as a repair system for the body, they are known a replenishing types of cell, but also maintain the normal outcome of cloned organs, such as blood, skin or tissues.(7)
Stem cell treatments are a type of cell therapy that introduces new cells into damaged tissue in order to treat a disease or injury(5). Many scientists and medical researchers think that treatments in stem cell research may have the ability to lessen human disease and lessen suffering. Since stem cells have the ability to self-renew themselves and could also give help to the generations in the future by replacing diseased and damaged tissues in the body, without any risk of rejection. (7)
Many types of stem cell treatments exist, even though most experiments are still experimental and/or costly, with the high exception of bone marrow transplantation.(4) Medical researchers hope that one day they will be able to use technologies used from adult and embryonic stem cell research to treat cancer, Parkinson's disease, Type 1 diabetes mellitus, cardiac failure, Huntington's disease, neurological disorders and muscle damage, along with many others.(4)
For over 15 years, bone marrow, and more recently, umbilical cord blood stem cells have been used to treat cancer patients with conditions such as leukemia and lymphoma. During chemotherapy, most growing cells are killed by the cytotoxic agents. These agents not only kill the leukemia or neoplastic cells, but also cure the stem cells within the bone marrow.(7) It is this side effect of the chemotherapy that the stem cell transplant attempts to reverse; the donor's healthy bone marrow gives back functional stem cells to replace those lost in the treatment.(4)
The status of the human embryo and human embryonic stem cell research is a controversial matter as, the creation of a human embryonic stem cell line requires the killing of a human embryo. Stem cell debates have motivated and reinvigorated the pro-life movement, whose members are concerned with the rights and status of the embryo as an early-aged human life. They believe that embryonic stem cell research violates the sanctity of life and is an indirect murder.(12) The main claim of those who oppose embryonic stem cell research is the belief that human life is sacred, combined with the fact that human life begins when a sperm cell fertilizes an egg cell to form a single cell.(11)
In August, 2000, The U.S. National Institutes of Health's Guidelines stated:
"...research involving human pluripotent stem cells...promises new treatments and possible cures for many debilitating diseases and injuries, including Parkinson's disease, diabetes, heart disease, multiple sclerosis, burns and spinal cord injuries. The NIH believes the potential medical benefits of human pluripotent stem cell technology are compelling and worthy of pursuit in accordance with appropriate ethical standards." (14)
Medical researchers widely believe that stem cell research has the potential to largely change approaches to understanding and treating diseases, and to alleviate suffering. In the future, most medical researchers anticipate being able to use technologies taken from stem cell research to treat a variety of diseases and impairments. Spinal cord injury is an example that has been recognised by large media actors such as, Christopher Reeve and Michael J. Fox. The anticipated medical benefit of stem cell research adds the need to the debates, which has been appealed to by embryonic stem cell research.(7)
Many examples of cloning exist, but natural cloning has been here since the dawn of time. Identical twins are examples of how all clones are not experiments. Single celled organisms like yeast germs are created by themselves, this process is called asexual reproduction. Asexual reproduction is where one cell grows a big enough nucleus to split into another cell, even plants make other plants asexually.(5)When plants reproduce asexually the process is called vegetative propagation. This process is where a stem or root that is planted makes an exact replica of itself. Farmers use this technique to make more plants, fruits, and vegetables. Natural cloning is one of safest cloning there is because it can not endanger any lives. Although we know much about natural cloning there is still a lot to learn.(8)
Mitosis is the process by which a cell separates the chromosomes in its cell nucleus into two identical sets in the nuclei. After that it immediately goes through cytokinesis, which is the final stage of cell reproduction and divides the nuclei, cytoplasm and cell membrane into two daughter cells containing roughly equal shares of these cellular characteristics. Mitosis and cytokinesis together shows the mitotic phase of the cell cycle, which is the division of the mother cell into two daughter cells, genetically identical to each other and to their parent cell.(1)
Mitosis occurs exclusively in eukaryotic cells, but occurs in different ways in different species. For example, animals undergo an "open" mitosis, where the nuclear envelope breaks down before the chromosomes separate, while yeast undergo a "closed" mitosis, where chromosomes divide within an intact cell nucleus.(12) Prokaryotic cells, which lack a nucleus, divide by a process called binary fission, which is the form of asexual reproduction and cell division used by all prokaryotic and some eukaryotic organisms, which are both cells with complex structures.
The process of mitosis is complex; the chain of events is separated into phases, related to the end of one set of activities and the start of the next. These stages are prophase, prometaphase, metaphase, anaphase and telophase.(1) During the process of mitosis the pairs of chromosomes condense and attach to fibres that pull the sister chromatids to opposite sides of the cell. The cell then divides in cytokinesis, to produce two identical daughter cells.(12)
Cytokinesis usually occurs together with mitosis and is often used together with mitotic phase. However, there are many cells where mitosis and cytokinesis occur separately, forming single cells with multiple nuclei. This occurs mostly among the fungi and slime moulds, but is found in various different groups. Even in animals, cytokinesis and mitosis may occur independently. Errors in mitosis can cause mutations that may lead to cancer.(1)
Dolly the Sheep
Dolly was born July 5, 1996 and passed away on February 14, 2003, she was a female sheep and was the first mammal to be cloned from an adult somatic cell, using the process of nuclear transfer. She was cloned by Ian Wilmut, Keith Campbell and colleagues at the Roslin Institute in Edinburgh, Scotland. She was born on July 5, 1996 and she lived until the age of six, and was known as "the world's most famous sheep" by Scientific American.(20) The donor cell used for the cloning of Dolly was taken from a mammary gland, which are the organs that, in mammals, produce milk.(19) The creation of this healthy clone proved that a cell taken from a specific part of the body could remake a genetically similar clone. Dolly was named after the famous country western singer Dolly Parton.
This used the technique of Somatic cell nuclear transfer, where the cell nucleus from an adult cell is transferred into an unfertilised oocyte, a developing egg cell that has had its nucleus removed. The cell is then stimulated to divide by an electric shock, and when it develops into a blastocyst, which a structure formed in the early embryo of mammals, it is implanted in a surrogate mother.(19)
On February 14, 2003, Dolly was diagnosed with a progressive lung disease and severe arthritis. A Finn Dorset sheep such as Dolly has a life expectancy of around 11 to 12 years, but Dolly was only six years of age. A after death analysis showed she had a form of lung cancer called Jaagsiekte that is a fairly common disease of sheep.(20) Roslin scientists said that they did not think there was a connection with Dolly's being a clone, and that other sheep in the same flock had died of the same disease. This lung disease is a particular danger for sheep kept indoors, and Dolly had to sleep inside for security reasons.(20)
Pros of Cloning
If the vital organs of the human body can be cloned, they can be backup systems for human beings. Cloning body parts can serve as a lifesaver. When a body organ such as a kidney or heart fails to function, it may be possible to replace it with the cloned body organ.
Cloning in human beings can prove to be a solution to infertility.(16) Cloning has the potential of serving as an option for producing children. Cloning may make it possible to reproduce a certain part in human beings. Humans will be able to produce people with certain qualities, and particular wanted organs or traits. Cloning technologies can prove helpful for the researchers in genetics.(3) They might be able to understand the composition of genes and the effects of genetic parts on human traits, in a better way. They will be able to change genetic parts in cloned human beings and better understand their study of genes. Cloning may also help us combat a wide range of genetic diseases. Cloning can make it possible for us to have special organisms and have them for health benefits of people. Cloning can serve as the best way to replicate animals that can be used for research purposes. Cloning can enable the genetic change of plants and animals. If positive changes can be brought about in human beings with the help of cloning, it will indeed be a large benefit to mankind. (2)
Cons of Cloning
Cloning is creating identical genes, it is a process of replicating a genetic constitution and is changing the diversity in genes. While lessening the diversity in genes, we weaken our ability of adaptation. Cloning is also harmful to the beauty that lies in diversity. While cloning allows man to change genetics in human beings, it also makes deliberate reproduction of undesirable traits.(16) Cloning of body organs might invite abuse in society. In cloning human organs and using them for transplant or in cloning human beings themselves, there are economic barriers will have to be considered. Cloned organs will be at an extremely high price which could cause problems in social levels, then will cloning cannot help the common man. Cloning will put human and animal rights at stake.(2) Cloning could cause ethical and moral principles to be broken and cause riots of religious groups. Cloning will leave human beings just another man-made thing and the decrease the value of life. Cloning is also equal to acting as God and humans might not be able to take on such a responsibility.(16)
In conclusion cloning has its benefits and its disadvantages just like most experiments. I gave the facts on how it is done and what is has done to help humans so far, but saying if cloning is right or wrong is a hard thing to say. Cloning help humans in the future which for me sounds great but what if we overpopulated? In the end my view on cloning will stay at dilemma because the subject is too hard to choose whether it is right or wrong.