Definition: a number of different processes that can be used to produce genetically identical copies of a biological entity.
There are three different types of artificial cloning: gene cloning, reproductive cloning and therapeutic cloning.
Gene cloning produces copies of genes or segments of DNA. How it works: procedure consists of inserting a gene from one organism, often referred to as "foreign DNA," into the genetic material of a carrier called a vector.
Reproductive cloning produces copies of whole animals. How it works: researchers remove a mature somatic cell, such as a skin cell, from an animal that they wish to copy. They then transfer the DNA of the donor animal's somatic cell into an egg cell, or oocyte, that has had its own DNA-containing nucleus removed.
Therapeutic cloning produces embryonic stem cells for experiments aimed at creating tissues to replace injured or diseased tissues. How it works: involves creating a cloned embryo for the sole purpose of producing embryonic stem cells with the same DNA as the donor cell. These stem cells can be used in experiments aimed at understanding disease and developing new treatments for disease. To date, there is no evidence that human embryos have been produced for therapeutic cloning.
Gene cloning is a carefully regulated technique that is largely accepted today and used routinely in many labs worldwide. However, both reproductive and therapeutic cloning raise important ethical issues, especially as related to the potential use of these techniques in humans.
Reproductive cloning is a very inefficient technique and most cloned animal embryos cannot develop into healthy individuals.
Organismal or reproductive cloning is a technology used to produce a genetically identical organism—an animal with the same nuclear DNA as an existing, or even an extinct, animal.
Gene cloning is the most common type of cloning done by researchers at the National Human Genome Research Institute (NHGRI). NHGRI researchers have not cloned any mammals and NHGRI does not clone humans.
High Tech Genetics- Bioformatics and Microarray:
Definition: Microarray- DNA microarrays were used only as a research tool. Scientists continue today to conduct large-scale population studies. Bioformatics- the science of collecting and analyzing complex biological data such as genetic codes.
Microarrays can also be used to study the extent to which certain genes are turned on or off in cells and tissues. In this case, instead of isolating DNA from the samples, RNA (which is a transcript of the DNA) is isolated and measured.
A bioinformatics scientist is someone who applies information technology and computer science into the area of biology. This is done for the purpose of studying, analyzing, and processing genomic information as well as other forms of biological information. They also study and dissect large amounts of datasets at the molecular level such as proteomics, raw micro array, and genomic sequence data. They also manipulate databases that are commercially or publicly accessible, which contain genomic and post genomic data. They design and update any web-based informatics tools they may need. They will also change existing software applications to fit the needs of any projects they may be working on, and, if necessary, create a whole new software application for the job.
The use computer technology helps get the information that’s stored in certain types of biological data.
Genetically Modified Organisms:
Definition: A GMO (genetically modified organism) is the result of a laboratory process where genes from the DNA of one species are extracted and artificially forced into the genes of an unrelated plant or animal.
How it works: When a gene from one organism is purposely moved to improve or change another organism in a laboratory, the result is a genetically modified organism (GMO). It is also sometimes called "transgenic" for transfer of genes. There are different ways of moving genes to produce desirable traits.
Technology is used to modify the DNA in different things so that plants or animals can produce more.
Ethical Issues: the use of genetically modified organisms is a practice still in its infancy. The long-term effects of this technology are yet to be seen, and thus we must proceed with caution as we develop our practices and guidelines.
Environmental benefits: Less chemicals, time, machinery, and land are needed for GMO crops and animals, which can help reduce environmental pollution, greenhouse gas emissions, and soil erosion. Enhanced productivity because of GMOs could allow farmers to dedicate less real estate to crops.
Stem cell research – Adult vs. Embryonic:
Definition: Embryonic stem cells can become all cell types of the body because they are pluripotent. Adult stem cells are thought to be limited to differentiating into different cell types of their tissue of origin. Embryonic stem cells can be grown relatively easily in culture.
How it works: Adult stem cells have been identified in many organs and tissues, including brain, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver, ovarian epithelium, and testis. They are thought to reside in a specific area of each tissue (called a "stem cell niche"). In many tissues, current evidence suggests that some types of stem cells are pericytes, cells that compose the outermost layer of small blood vessels. Stem cells may remain quiescent (non-dividing) for long periods of time until they are activated by a normal need for more cells to maintain tissues, or by disease or tissue injury.
Human embryonic and adult stem cells each have advantages and disadvantages regarding potential use for cell-based regenerative therapies. One major difference between adult and embryonic stem cells is their different abilities in the number and type of differentiated cell types they can become. Embryonic stem cells can become all cell types of the body because they are pluripotent. Adult stem cells are thought to be limited to differentiating into different cell types of their tissue of origin.
Stem cells can be derived from a variety of tissues. Adult, fetal, placental, umbilical, and embryonic stem cells all have different properties. Adult stem cells can be obtained from the blood, bone marrow, brain, pancreas, and fat of adult bodies. Embryonic stem cells are found in very early embryos, and can be obtained from "supernumerary" or "leftover" embryos donated by couples undergoing in vitro fertilization (IVF) treatment. Scientists have also derived embryonic stem cells from clonal human embryos.
Gene therapy and Genomic medicine:
Definition: Gene therapy is an experimental technique that uses genes to treat or prevent disease. In the future, this technique may allow doctors to treat a disorder by inserting a gene into a patient’s cells instead of using drugs or surgery. Genomic medicine is an approach to medical diagnosis, treatment, and risk assessment based on an individual’s genome (genetic make-up) and gene expression patterns. The past decade has been a time of research and discovery for genomic medicine (a.k.a. personalized medicine, individualized medicine, precision medicine, molecular medicine). Scientists involved in translational research are using collaborative methods in an effort to accelerate the development of useful clinical tools.
How it works: Gene therapy is designed to introduce genetic material into cells to compensate for abnormal genes or to make a beneficial protein. If a mutated gene causes a necessary protein to be faulty or missing, gene therapy may be able to introduce a normal copy of the gene to restore the function of the protein.
There are several technologies that have the potential to create medicines in this field. These technologies can be grouped into two broad categories: gene augmentation and genome editing. Each approach seeks to address genetically defined diseases at the level of DNA. However, gene augmentation, which is commonly called gene therapy, and genome editing differ fundamentally with regard to the kind of genomic change they seek to accomplish.
Although great strides have been made in gene therapy in a relatively short time, its potential usefulness has been limited by lack of scientific data concerning the multitude of functions that genes control in the human body. For instance, it is now known that the vast majority of genetic material does not store information for the creation of proteins, but rather is involved in the control and regulation of gene expression, and is, thus, much more difficult to interpret. Even so, each individual cell in the body carries thousands of genes coding for proteins, with some estimates as high as 150,000 genes. For gene therapy to advance to its full potential, scientists must discover the biological role of each of these individual genes and where the base pairs that make them up are located on DNA.
Genomic medicine is a powerful way to tailor health care at the individual level by using patients' genomic information. By identifying the genetic factors associated with disease, it is possible to design more effective drugs; to prescribe the best treatment for each patient; to identify and monitor individuals at high risk from disease; and to avoid adverse drug reactions (National Human Genome Research Institute, 2005).
Designs Baby and Bioethics:
Definition: A designer baby is a baby genetically engineered in vitro for specially selected traits, which can vary from lowered disease-risk to gender selection. Bioethics: the ethics of medical and biological research.
Bioethicists have argued that parents have a right to prenatal autonomy, which grants them the right to decide the fate of their children.
Benefits: Prevents genetic diseases such as Down Syndrome, Alzheimer's, Huntington's Disease, Spinal Muscular Atrophy, and many others. Reduces risk of inherited medical conditions such as obesity, anemia, diabetes, cancer, and many more. Allows parents to give their child a better shot at a healthy lifestyle.
During a pre-implantation genetic diagnosis or embryo screening, a scientist would be able to tell what physical characteristics a child will grow to have; as well as whether or not this child is at risk of developing or will develop genetic disorders such as autism, down syndrome, Huntington’s disease, Alzheimer’s and many other disorders such as these. Designer babies are generally made through in-vitro fertilization where the embryo is removed from a women and is manipulated in a lab to have certain desired qualities and then placed into a females womb to finish development.
Since this technology has been developed some people use this process to have children that will be an exact match to an older sibling who is terminally ill. This way there is always someone who can donate organs, blood, bone marrow and other such body parts.
Many people argue that it is unethical and unnatural to be able to create your own baby the way you want it, while others argue that it could be used to stop certain genetic diseases in babies.
Definition: the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself.
How it works: It can apply to characteristics passed from a cell to its daughter cells in cell division and to traits of a whole organism. Many researchers have been studying epigenetics over the past few decades, and it is currently an area of intense research activity. We know that a part of how epigenetics works is by adding and removing small chemical tags to DNA. You can think of these tags as post-it notes that highlight particular genes with information about whether they should be switched on or off.
One thing that scientists have discovered is that epigenetic errors are common in diseases such as cancer and in ageing cells.
Two broad areas of epigenetics are DNA methylation and histone modifications and numerous techniques have been invented to analyze epigenetic processes not only at the level of specific genes, but also to analyze epigenetic changes that occur in defined regions of the genome as well as genome-wide. Advances have also been made in techniques devised to assess the enzymes that mediate epigenetic processes. These methods that are currently driving the field of epigenetics will greatly facilitate continued expansion of this exponentially growing discipline of genetics.
A key implication of epigenetics research is that many environmental and hazardous exposures will affect not only the exposed individuals, but possibly their progeny and subsequent generations. Epigenetic effects have been associated with exposure to various toxic chemicals, airborne pollutants, pesticides and other harmful substances. Many of these exposures are linked with poverty, discriminatory land use, and substandard living and working conditions. At the same time, many individuals with these harmful exposures are considered medically vulnerable because of pre-existing health conditions that are frequently complicated by poor clinical management.
DNA fingerprinting and crime scene investigation:
Definition: DNA fingerprinting, one of the great discoveries of the late 20th century, has revolutionized forensic investigations. This review briefly recapitulates 30 years of progress in forensic DNA analysis which helps to convict criminals, exonerate the wrongly accused, and identify victims of crime, disasters, and war.
How it works: Current standard methods based on short tandem repeats (STRs) as well as lineage markers (Y chromosome, mitochondrial DNA) are covered and applications are illustrated by casework examples. Benefits and risks of expanding forensic DNA databases are discussed and we ask what the future holds for forensic DNA fingerprinting.
In the classical DNA fingerprinting method radio-labeled DNA probes containing minisatellite or oligonucleotide sequences are hybridized to DNA that has been digested with a restriction enzyme, separated by agarose electrophoresis and immobilized on a membrane by Southern blotting or - in the case of the oligonucleotide probes - immobilized directly in the dried gel. The radio-labeled probe hybridizes to a set of minisatellites or oligonucleotide stretches in genomic DNA contained in restriction fragments whose size differ because of variation in the numbers of repeat units. After washing away excess probe the exposure to X-ray film (autoradiography) allows these variable fragments to be visualized, and their profiles compared between individuals.
The steady growth in the size of forensic DNA databases raises issues on the criteria of inclusion and retention and doubts on the efficiency, commensurability, and infringement of privacy of such large personal data collections. In contrast to the past, not only serious but all crimes are subject to DNA analysis generating millions and millions of DNA profiles, many of which are stored and continuously searched in national DNA databases. And as always when big datasets are gathered new mining procedures based on correlation became feasible.
At present the forensic DNA technology directly affects the lives of millions people worldwide. The general acceptance of this technique is still high, reports on the DNA identification of victims of the 9/11 terrorist attacks, of natural disasters as the Hurricane Katrina, and of recent wars (for example, in former Yugoslavia) and dictatorship (for example, in Argentina) impress the public in the same way as police investigators in white suits securing DNA evidence at a broken door. CSI watchers know, and even professionals believe, that DNA will inevitably solve the case just following the motto Do Not Ask, it’s DNA, stupid! But the affirmative view changes and critical questions are raised. It should not be assumed that the benefits of forensic DNA fingerprinting will necessarily override the social and ethical costs.
Personal Ancestry: the actual or hypothetical form or stock from which an organism has developed or descended. Paternity kits: a medical test, typically a blood test, to determine whether a man may be the father of a particular child.
How it works: To carry out a paternity test, scientists take a pinprick of blood from the child, the mother and the supposed father. Half the DNA fragments that make up a child's STR profiles come from the mother and half from the natural father.
DNA technology has revolutionized modern science. As it evolves, more and more applications are discovered to help us understand all living organisms and most importantly ourselves as human beings. DNA, or the genetic material—passed along from one generation to the next—holds many clues that have unlocked the mysteries behind human behavior, biological inheritance, biological identities, genetic diseases, evolution, and aging. Recent advances in DNA technology including PCR, cloning, DNA fingerprinting, gene therapy and genetic disease diagnosis have started to shape medicine, forensic sciences, environmental sciences, and national security.
DNA testing is a reliable and accurate and nowadays paternity DNA testing, ancestry and other similar tests can give you invaluable information that you may need to find peace of mind. However, DNA testing does give rise to some basic issues which carry ethical bearing.
PCR and Gel Electrophoresis:
Definition: PCR- Polymerase chain reaction, or PCR, is a laboratory technique used to make multiple copies of a segment of DNA. PCR is very precise and can be used to amplify, or copy, a specific DNA target from a mixture of DNA molecules.Gel Electrophoresis- is a method for separation and analysis of macromolecules (DNA, RNA and proteins) and their fragments, based on their size and charge.
How it works: To amplify a segment of DNA using PCR, the sample is first heated so the DNA denatures, or separates into two pieces of single-stranded DNA. Next, an enzyme called "Taq polymerase" synthesizes - builds - two new strands of DNA, using the original strands as templates.
Some people consider PCR unethical, because since DNA is produced so quickly and easily, it might bepossible for outside sources to obtain a copy of it for their own use without the owner's permission.
Polymerase chain reaction (PCR) is a technique used to exponentially amplify a specific target DNA sequence, allowing for the isolation, sequencing, or cloning of a single sequence among many.
DNA fragments are negatively charged, so they move towards the positive electrode. Because all DNA fragments have the same amount of charge per mass, small fragments move through the gel faster than large ones.
Plasmids, Recombinant DNA and Transgenic organisms:
Definition: Plasmids- A plasmid is a small, circular, double-stranded DNA molecule that is distinct from a cell's chromosomal DNA. Plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes. Often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance. Recombinant DNA- DNA that has been formed artificially by combining constituents from different organisms. Transgenic Organisms- This process is also known as “genetic engineering.” Genes of one species can be modified, or genes can be transplanted from one species to another. Genetic engineering is made possible by recombinant DNA technology. Organisms that have altered genomes are known as transgenic.
Scientists have taken advantage of plasmids to use them as tools to clone, transfer, and manipulate genes. Plasmids that are used experimentally for these purposes are called vectors. Researchers can insert DNA fragments or genes into a plasmid vector, creating a so-called recombinant plasmid. This plasmid can be introduced into a bacterium by way of the process called transformation. Then, because bacteria divide rapidly, they can be used as factories to copy DNA fragments in large quantities.
Transgenic organisms contain altered genes from other organisms. The process of creating a transgene includes isolating the gene of interest from the tens of thousands of other genes in the genome of a gene-donor species. Once that gene is isolated, it is usually altered so it can function effectively in a host organism. That gene is then combined with other genes to prepare it to be introduced into another organism, at which point it's known as a transgene. A transgenic organism, sometimes called a chimera, is one that contains a transgene introduced by technological methods rather than through selective breeding.
Recombinant DNA biotechnology is the latest in a long line of tools that plant breeders have used to enhance plant availability, survival, and growth to benefit people. In little more than a century, starting with hybridization, which was commercialized in the first decade of the 20th century, scientific breakthroughs enabled new types of plants, such as seedless watermelons and grapes, to be produced. Plant breeding often has been successful in producing plants with increased pest and disease resistance, while retaining high yields, taste, and processing attributes.