In 1885, the first ever successful artificial cloning of an embryo was conducted on a sea urchin. A biologist, Dr. Hans Adolf Eduard Driesch of Germany, used a sea urchin for his studies and embryonic development. He took a sea urchin, removed a two-celled embryo and was able to separate the cells. Once it was separated, each cell grew into complete identical sea urchins. The sea urchins had its own genetic markup and grew into two full organisms. In 1902, embryologist Dr. Hans Spemann, used the same method on a two-celled embryo of a salamander and was also successful. In 1951, Dr. Robert Briggs and Thomas King were able to successfully transfer a nucleus from a tadpole embryo and inserted it into an enucleated egg from a frog. In turn, this cell turned into a tadpole. Prior experiments using methods other than the nucleus weren’t successful and resulting in the organism to grow abnormally but this nuclear transfer method was successful. In 1984, the first successful mammalian organism was created by scientist Steen Willadsen using cells from a lamb. All the cells that were obtained for these experiments were from embryonic cells. In 1996, scientist Ian Wilmut and Keith Campbell performed the first successful somatic cell nuclear transfer that was obtained from adult cells of a sheep and inserting it into a surrogate sheep. The surrogate sheep mother was able to carry a full term lamb. Through many failed experiments, only 1 was able to be born at full term, and the scientists names this female lamb, Dolly. Dolly paved a way for future cloning experiments, along with bringing controversies on human cloning and stem cell research to the public (Genetic Science Learning Center, 2014).
From 1996 and on, there have been several successful animal cloning experiments. Scientists began trying to clone endangered animals. However, scientists realized this was doing more damage to the endangered animals more than helping the species survive due to birth defects of the clones and rigorous experiments of the animals. In 2007, researchers took monkey embryonic stem cells and fused it with an enucleated egg. From this experiment, the cells were able to grow and differentiate on a culture dish. According to the researchers, from this outcome, they believed that it is possible to use on human therapeutic cloning.
To this date, there are three types of artificial cloning: genetic cloning, reproductive cloning, and therapeutic cloning (as I mentioned above). Genetic cloning involves the process of cloning DNA segments and complementary DNA of the messenger mRNA. This is used as a genetic cloning techniques to make copies of genes the researchers want to study individually (Miki et al, 1989). Gene cloning uses a carrier known as a vector. Researchers obtain a gene called a foreign DNA gene, and inserts it into the vector. Some examples of vectors that are used for research are bacteria, yeast, viruses, and plasmids. The vector is observed and data is collected for study. In reproductive cloning, it involves creating an mammalian organism that is genetically identical to the parent donor. This is performed through somatic cell nuclear transfer. The newly obtained embryo is placed into the uterine where it can implant and grow. Dolly, the lamb is an example of a successful somatic nuclear cell transfer. In therapeutic cloning, the cloned cells are kept on a petri dish in the lab and are not inserted into the uterine. This type of cloning serves the sole purpose of producing embryonic stem cells with identical DNA as the door cell. (NY STEM, n.a).
Over the last two decades, there are been little to no solid evidence of successful human cloning. In 1998, scientists in South Korea claimed that they successfully cloned a human embryo but added that when experiment was interrupted at a very early stage in the process and revealed no scientific proof. Some researchers believe that cloning can help with genetic diseases and provide treatment or preventative measures in the future. However, controversy involving the procedure of obtaining these cells have been debated.
According to a published journal article by Dr. Stephan Robertson, he stated that successful human cloning is unlikely due to technical difficulties of obtaining samples and keeping them viable. He also stated that if ever, it does happen, he believes that cloning promises scientific opportunities in a different aspect. He stated that human cloning should not be for purposes of unreasonable desirable outcomes, but instead to further extend scientific research and possibly be used for medical experiments.
According to another article written by Dr. Harris, he stated his opinions on human cloning in opposing the article of Dr. Stephan Robertson. Dr. Harris says sexual reproduction to procreate in a natural framework should be considered rather than creating a humans from a laboratory. The idea of human cloning serves no purpose and Harris argued that every human being has a natural genetic code. He stated there is no legislative, medical, or ethical entities that can safeguard real humans in the unethical use of human cloning ( Harris, 1997).
Although successful animal cloning has been achieved, researchers have admitted that reproductive cloning is inefficient. Cloned animal embryos cannot develop properly and risks several animal embryos of dying before even one can starts to grow in the laboratory.
Throughout many years of on-going research, there have been no evidence that human cloning is successful. According to the National Human Genome Research Institute, gene cloning is regulated by a technique that is carefully monitored by rules and regulations. Gene cloning is the only technique that is largely accepted today and used all over the world. However, reproductive and therapeutic cloning still is a topic for controversial discussion importantly because of ethical issues in using real humans in experiments. While researchers say that therapeutic cloning can offer treatment of diseases to a variety of illnesses, this method of collecting embryos for stem cells is seen as unethical due to the nature of the destroying human embryos in the process (NIH, 2017).