Brief History of GM Animals Development In 1974, Rudolf Jaenisch and Beatrice Mintz created the first genetically modified (GM) animal which carried the modified gene in its tissue. It was a transgenic mice created by insertion of foreign DNA into early-stage mouse embryos (Jaenisch & Mintz 1974; Jones 2011). The term ‘transgenic’ was, however, first introduced by Gordon and Ruddle in 1981 when they created a GM mouse that was capable of passing specified foreign genes to its offspring (Gordon & Ruddle 1981; Jones 2011). They did so by microinjection of recombinant plasmid carrying a portion of the SV40 virus and the herpes simplex virus thymidine kinase (TK) gene into single-celled mouse embryos. Only two of the 78 injected mice were transformed and the integration of the DNA into the host genome was random, nevertheless their study showed that DNA c... ... middle of paper ... ...views Genetics 2, 743-755.
They tested to see if infertile male mice lack the Y chromosome long arm and generate live offspring. When the structure of abnormal sperm are delivered in an immature egg cell in the ovary by a vitro fertilization procedure where a sperm is injected into an egg. The Y chromosome inside the mouse is reduced from 78 Mb to about 2 Mb and encodes seven genes and three gene families. Animal testes are determined by the SRY and signals gonads to make differentiation. On the occasion with the addition of SRY, mice with one chromosome develop testis that are inhabited in any cells in the gonads.
I did not know there were different types of artificial cloning including “reproductive cloning, DNA cloning, and therapeutic cloning” (“Gene Therapy”). I was not aware of the first genetically identical mice were split during 1979 according to the National Human Genome Research Institute (“1998 Release”). From cloning, this eventually opened doors to therapeutic and stem cell research. As controversial as it is, the health benefits of cloning outweigh the cons. “With multiple types of cloning in gene cloning, it produces copies of genes or segment of DNA” (“Cloning Fact Sheet”).
Because of this definition, any identical twin could also be considered a clone. However, it is artificial cloning that has sparked the interest of scientists in our time. There are three different types of artificial cloning: genetic cloning, molecular cloning and therapeutic cloning, but human and animal cloning is done through genetic cloning. Genetic cloning occurs when a body cell is taken from an embryo in an early stage of development. The nucleus is then transferred to an unfertilized ovum from which the nucleus has been removed.
In 1972, Herbt Boyer and Stanley Cohen developed genetic information with replication in species and the first recombinant DNA organism. Two years later, Stanley Cohen, Annie Chang, and Herbert Boyer created the created the first GMOs. Then, Rudolf Jaenisch created the first genetically modified animal through the use of foreign DNA into a mouse embryo (GMO Regulation Timeline, n.d). This led to the U.S government to develop regulation on experimenting recombinant DNA. In 1976, the U.S government with the National Institute of Health (NIH) introduced the first committee, called the Recombinant DNA Advisory Committee (RAC).
Technology Ethic: Stem Cells Stem Cell: Stem cells can be thought of as blank slates or cells that have yet to become specialized. They can be transformed to become cells with special functions. History/Background of Stem Cells: In the mid 1960's, R. G. Edwards and colleagues at Cambridge University began studying differentiation of rabbit embryonic cells in an artificial environment. They manipulated these embryonic cells into specific types of form such as connective tissue and muscle neurons. Richard Gardner, a graduate student of R. G. Edwards, had furthered the experiment with mice blastocoels.
A stem cell being able to make cartilage and bone seems like a preposterous idea, does it not? With the invention of the microscope in the 1800’s, it was not long before scientists were able to discern that some cells were able to generate and change into other cells. This was the beginning of stem cell research. In 1961, Dr.’s Till and McCullough were studying the effects of radiation on the bone marrow of mice, when they discovered the existence of multipotent stem cells. In 1998, James Thomson at the University of Wisconsin-Madison isolated human embryonic stem cells, then demonstrated how they specialize and rejuvenate.
Scientists discovered ways to obtain stem cells from experiments with mouse embryos, more than 20 years ago! (It would seem knowledge of stem cells would be much farther along by now) Many years of detailed study of the biology of mouse stem cells led to the discovery, in 1998, of how to isolate stem cells from human embryos and grow the cells in the laboratory. The embryos used in these studies were created for infertility purposes with “in vitro fertilization”. Stem cells are important for living organisms for many reasons. During the first stages of a developing embryo, stem cells organize themselves into a certain order which will give rise to the multiple specialized cell types that make up the heart, lung, skin, and other tissues.
It’s all about genetics and DNA and what humans can do to further our knowledge with the human anatomy. Not all people agree with cloning and eugenics like some scientists do which causes a lot of controversy. Spearmann thought of cloning as a way to study cell differentiation. Briggs and King used the technique of nuclear transfer on amphibians and it was successful (Campbell). “Subsequently John Gurdon demonstrated the potential to reprogram differentiated cells by producing adult Xenopus using epithelial cells from developing tadpole intestine as nuclear donors,” says Alberio Campbell.
He used the buffer conditions identified by Barr D. Bavister to activate human spermatozoa and fertilize in vitro oocytes in 1969, however the fertilized oocytes were not progressing beyond the second stage, which lead him to try to use oocytes that completed their maturation process inside the body. Laparoscopy was a new method at the time, and it allowed surgeons to remove oocytes at the appropriate stage of development. Laparoscopy is a procedure where a lighted tube is inserted through the abdomen, requiring only a small incision (WebMD 1). In 1971, this discovery, with the help of his colleague, Patrick Steptoe, allowed for advancements to the development of 8-cell stage embryos, and later 16-cell stage and blastocysts (Nobelprize.org 6,7). The final error that called for correction was the hormone treatments women were receiving to induce oocyte maturation, which they decided to stop the use of this method entirely.