Various genetic discoveries have been essential in the development of genetic engineering. Genetic inheritance was first discovered by Gregor Mendel in following experiments crossing peas. Although largely ignored for 34 years he provided the first evidence of hereditary segregation and independent assortment. Edward Lawrie Tatum and George Wells Beadle developed the central dogma that genes code for proteins in
Cloning is frequently employed to amplify DNA fragments containing genesan essential step in their subsequent analysis. Frequently, the term cloning is misleadingly used to refer to the identification of the chromosomal location of a gene associated with a particular phenotype of interest.
In practice, localisation of the gene does not always enable one to amplify the relevant genomic sequence.
Cloning of any DNA sequence involves the following four steps: Initially, the DNA fragment of interest needs to be amplified many copies need to be produced. Amplification is commonly achieved by means of PCR. Subsequently, a ligation procedure is employed whereby the amplified fragment is inserted into a vector.
The vector which is frequently circular is linearised by means of restriction enzymes, and incubated with the fragment of interest under appropriate conditions that allow for ligation. The yield of the ligation is typically low and depends on the procedure employed.
Following ligation the vector with the insert of interest is transfected to cells. Most commonly electroporation is employed, although a number of alternative techniques are available, such as chemical sensitivation of cells.
Finally, the transfected cells are cultured. As the aforementioned procedures are of particularly low yield, there is the need to identify the cell colonies that have been transfected with the construct of interest containing the desired insertion sequence.
Modern cloning vectors include selectable antibiotic resistance markers, which allow only for cells in which the vector has been transfected to grow.
However this selection step does not guarantee that the DNA insert is present in the vector. Further investigation of the resulting colonies is required to confirm that cloning was successful.
Genetic cloning Cloning a cell means to derive a clonal population of cells from a single cell. This is an important in vitro procedure when the expansion of a single cell with certain characteristics is desired, for example in the production of gene-targeted ES cells.
Most individuals began as a single cell and are therefore the result of clonal expansion in vivo. Asexual reproduction Cloning means to create a new organism with the same genetic information as a cell from an existing one identical.
It is an asexual method of reproduction, where fertilization or inter-gamete contact does not take place. Asexual reproduction also known as agamogenesis is a form of reproduction which does not involve meiosisgamete formation, or fertilization. In laymen's terms, there is only one "parent" involved.
This form of reproduction is common among simple organisms such as amoeba and other single-celled organismsalthough most plants reproduce asexually as well see vegetative reproduction.
Horticultural The term clone is used in horticulture to mean all descendants of a single plant, produced by vegetative reproduction or apomixis.
Many horticultural plant cultivars are clones, having been derived from a single individual, multiplied by some process other than sexual reproduction. As an example, some European cultivars of grapes represent clones that have been propagated for over two millennia.
Other examples are potato and banana. Grafting can be regarded as cloning, since all the shoots and branches coming from the graft are genetically a clone of a single individual, although the root systems may be genetically genuine examples of cloning in the broader biological sense, as they create genetically identical organisms by biological means, but this particular kind of cloning has not come under ethical scrutiny and is generally treated as an entirely different kind of operation.
Many treesshrubsvinesferns and other herbaceous perennials form clonal colonies. Parts of a large clonal colony often become detached from the parent, termed fragmentationto form separate individuals. Some plants also form seeds asexually, termed apomixise.
Animals Cloning exists in nature in some animal species and is referred to as parthenogenesis. An example is the "Little Fire Ant " Wasmannia auropunctatawhich is native to Central and South America but has spread throughout many tropical environments.
Reproductive Cloning Reproductive cloning is a technology used to generate an animal that has the same nuclear DNA as another currently or previously existing animal. Dolly the sheepwas created by reproductive cloning technology.
In a process called " somatic cell nuclear transfer " SCNTscientists transfer genetic material from the nucleus of a donor adult cell to an egg whose nucleus, and thus its genetic material, has been removed.
The reconstructed egg containing the DNA from a donor cell must be treated with chemicals or electric current in order to stimulate cell division. Once the cloned embryo reaches a suitable stage, it is transferred to the uterus of a female host where it continues to develop until birth.
Dolly or any other animal created using nuclear transfer technology is not truly an identical clone of the donor animal. Only the clone's chromosomal or nuclear DNA is the same as the donor.Molecular cloning generally uses DNA sequences from two different organisms: the species that is the source of the DNA to be cloned, and the species that will serve as the living host for replication of the recombinant DNA.
Molecular cloning methods are central to many contemporary areas of . History Of Cloning Essay Examples. 19 total results. An Overview of the Purchase Issues During the Christmas in the United States of America.
2, words. 5 pages. Understanding the Process of Nuclear Transfer in Cloning. An Analysis and a History of the DNA Cloning in the United States. words. Dec 13, · To be used for molecular cloning, both vector and insert DNA are treated with restriction enzymes that cleave double stranded DNA molecules producing overhanging single .
Cloning is frequently employed to amplify DNA fragments containing genes, an essential step in their subsequent analysis. Frequently, the term cloning is misleadingly used to refer to the identification of the chromosomal location of a gene associated with a particular phenotype of interest.
|The Committee met in February and, after hearing the views of a panel of scientists and bioethicists began discussion of the topic.|
|Our experiences have told us that, with a little work, we humans can clone just about anything we want, from frogs to sheep—and probably even ourselves.|
|History[ edit ] Prior to the s, our understanding of genetics and molecular biology was severely hampered by an inability to isolate and study individual genes from complex organisms.|
DNA cloning, which is the production of multiple identical copies of a DNA fragment, is responsible for all sorts of things, such as pest-resistant . The donor DNA came from an 8-month-old with a rare genetic disease.
At least one biotechnology company in the United States has offered cat cloning services for the privileged and bereaved. But don't assume that your cloned kitty will be exactly the same as the one you know and love. On December 22, , a kitten named CC made history.