Cloning, the process of generating a genetically identical copy of a cell or an organism. Cloning happens all the time in nature—for example, when a cell replicates itself asexually without any genetic alteration or recombination. Prokaryotic organisms (organisms lacking a cell nucleus), such as bacteria and yeasts, create genetically identical duplicates of themselves using binary fission or budding. In eukaryotic organisms (organisms possessing a cell nucleus) such as humans, all the cells that undergo mitosis, such as skin cells and cells lining the gastrointestinal tract, are clones; the only exceptions are gametes (eggs and sperm), which undergo meiosis and genetic recombination. In biomedical research, cloning is broadly defined to mean the duplication of any kind of biological material for scientific study, such as a piece of DNA or an individual cell. For example, segments of DNA are replicated exponentially by a process known as polymerase chain reaction, or PCR, a technique that is used widely in basic biological research. The type of cloning that is the focus of much ethical controversy involves the generation of cloned embryos, particularly those of humans, which are genetically identical to the organisms from which they are derived, and the subsequent use of these embryos for research, therapeutic, or reproductive purposes. The ethical issues with reproductive cloning include genetic damage to the clone, health risks to the mother, very low success rate meaning loss of large numbers of embryos and fetuses, psychological harm to the clone, complex altered familial relationships, and commodification of human life. Animal cloning is becoming a useful technique for producing transgenic farm animals and is likely to be used to produce clones from valuable adults. 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.
Genetically modified organism (GMO), organism whose genome has been engineered in the laboratory in order to favour the expression of desired physiological traits or the production of desired biological products. In conventional livestock production, crop farming, and even pet breeding, it has long been the practice to breed select individuals of a species in order to produce offspring that have desirable traits. In genetic modification, however, recombinant genetic technologies are employed to produce organisms whose genomes have been precisely altered at the molecular level, usually by the inclusion of genes from unrelated species of organisms that code for traits that would not be obtained easily through conventional selective breeding. GMOs are produced through using scientific methods that include recombinant DNA technology and reproductive cloning. In reproductive cloning, a nucleus is extracted from a cell of the individual to be cloned and is inserted into the enucleated cytoplasm of a host egg. The process results in the generation of an offspring that is genetically identical to the donor individual. The first animal produced by means of this cloning technique with a nucleus from an adult donor cell (as opposed to a donor embryo) was a sheep named Dolly, born in 1996. Since then a number of other animals, including pigs, horses, and dogs, have been generated by reproductive cloning technology. Recombinant DNA technology, on the other hand, involves the insertion of one or more individual genes from an organism of one species into the DNA (deoxyribonucleic acid) of another. Whole-genome replacement, involving the transplantation of one bacterial genome into the “cell body,” or cytoplasm, of another microorganism, has been reported, although this technology is still limited to basic scientific applications. GMOs produced through genetic technologies have become a part of everyday life, entering into society through agriculture, medicine, research, and environmental management. However, while GMOs have benefited human society in many ways, some disadvantages exist; therefore, the production of GMOs remains a highly controversial topic in many parts of the world.
Stem cells are a class of undifferentiated cells that are able to differentiate into specialized cell types. Commonly, stem cells come from two main sources: Embryos formed during the blastocyst phase of embryological development (embryonic stem cells) and. Adult tissue (adult stem cells). It is transplanted routinely to treat a variety of blood and bone marrow diseases, blood cancers, and immune disorders. More recently, stem cells from the blood stream (called peripheral blood stem cells) and umbilical cord stem cells have been used to treat some of the same blood-based diseases. However, human embryonic stem cell (hESC) research is ethically and politically controversial because it involves the destruction of human embryos. In the United States, the question of when human life begins has been highly controversial and closely linked to debates over abortion. The hope going forward is that stem cells can also be used as a “renewable source of replacement cells and tissues” to treat common and serious diseases without the need for organ transplants or surgeries, including: macular degeneration, spinal cord injury, stroke, burns, heart disease, diabetes, osteoarthritis. Stem cells are also helpful in potentially treating problems like repair or replace damaged organs, birth defects, Parkinson's disease, spinal cord injuries and Alzheimer's disease. If people get good treatment of such diseases, it will be beneficial for them as well as the society. The confluence of human stem cell and genome research is laden with opportunity. Information gleaned from the Human Genome Project (HGP) has already done much to expand our understanding of human biology and disease.
DNA fingerprinting is a laboratory technique used to establish a link between biological evidence and a suspect in a criminal investigation. A DNA sample taken from a crime scene is compared with a DNA sample from a suspect. If the two DNA profiles are a match, then the evidence came from that suspect. The test is used to determine whether a family relationship exists between two people, to identify organisms causing a disease, and to solve crimes. Only a small sample of cells is needed for DNA fingerprinting. A drop of blood or the root of a hair contains enough DNA for testing. Ethical Issues need to be considered if the benefits are maximized and the harms minimized from the increasing ability to use Genetic testing to analyse an individual’s genetic information. It is a scientific technique based on making a profile of specific portions of an individual's DNA to establish identity, for example in paternity or maternity cases or in criminal investigations where biological material is left at a crime scene. Like nearly everything else in the scientific world, nothing about DNA fingerprinting is 100% assured. The term DNA fingerprint is, in one sense, a misnomer: it implies that, like a fingerprint, the VNTR pattern for a given person is utterly and completely unique to that person. Technology is used in this process and it is called microsatellite analysis. The human genome is made up of 3 billion nucleotides, which are 99.9% identical from one person to the next.
The molecular technique called PCR is in vitro amplification of a specific segment of DNA using a thermostable enzyme. The size of a DNA fragment can be estimated by gel electrophoresis. This technique separates fragments by charge, size (molecular weight) and shape. After running PCR, gel electrophoresis was completed, allowing us to analyze the bands that resulted from PCR. Each PCR assay requires the presence of template DNA, primers, nucleotides, and DNA polymerase. In conventional PCR, problems with reaction components and amplification protocols are diagnosed by running a gel. If you experience any of the symptoms pictured below when visualizing PCR products by agarose gel electrophoresis, click on the corresponding photo to learn about possible causes and treatments. PCR products are most commonly analyzed by agarose gel electrophoresis.