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A molecular genetic technique used for the direct manipulation, alteration or modification of genes or genome of organisms in order to manipulate the phenotypes is called genetic engineering.

Or in other words, we can say,

Genetic engineering is a technique using which the genetic composition of an organism can be altered.

The technique is often known as genetic manipulation, genetic modification or genetic alterations, broadly it is categorized as genetic engineering.

In this technique, a recombinant DNA is constructed and inserted into the host genome using a vector. Or we can delete some mutant sequences from a genome.The first recombinant DNA was constructed by Paul Berg in 1972.

Using the genetic engineering technique genetically modified organisms can be constructed which are economically very important for us.

It is employed for the production of improved plant species, therapeutic drugs or proteins, prevention of inherited genetic disorders and construction of a genetically modified organism.

In the present article, we will our major talk is genetic engineering and its applications. The content of the article is,

Humans are manipulating the genetic material of many organisms for long. Using selective breeding and cross-hybridization, economically important plant species were created by us.

The purpose of developing the genetic engineering or genetic manipulating technique is to produce organisms or phenotypes which are useful to us. Genetic engineering techniques are used for,

In genetic engineering, two different cells DNA are combined and inserted into the host genome via vector. Important components of the gene manipulation experiments are explained here.

Gene of interest: A DNA sequence which we want to insert in our target cells.

Vector: using the plasmid DNA like vectors the gene of interest is inserted into the host genome. Vectors are kind of vehicles which transfer the genetic material.

Target cells: target cells are the population of cells whose genome we wish to manipulate or change.The general process of gene therapy.

A technique used to insert or delete a mutant gene or to manipulate a genome of an organism is known as genetic engineering.

The term genetic engineering was first used by the science-fiction novelist, not by any scientist.In the year, 1951, Jack Williamson used the term genetic engineering for the first time in his novel Dragons island.

Soon after that, the molecular structure of the DNA was discovered by Watson and Crick, although the genetic experiments were popular since the time of Mendel.

The first recombinant DNA was constructed by Paul Berg in 1972. In the same year, Herbert Boyer and Stanley Cohen performed gene transfer experiments.In 1974, Rudolf Jaenisch had created genetically modified mice, the first time in the history of genetics.

After the success of Rudolf, the genetically modified or genetically engineered tobacco plant species was developed in 1976.

During this period (between 1960 to 1990) restriction digestion, ligation and PCR like techniques were discovered which gave wings to genetic engineering technology.

Related article: What is a genome?

Recombinant DNA- A recombinant DNA technology is a type of genetic engineering technology in which an artificial DNA molecule is constructed by ligating two different DNAs using physical methods.For that, the gene of interest is inserted into the plasmid vector and used for gene transfer experiments.

Gene delivering-Gene delivering technique is employed for the insertion of a gene of interest into the host genome.

Electrophoration, solicitation and viral vector-mediated gene transfer, liposome-mediated gene transfer, transposon-mediated gene transfer are some of the methods used for that.

Gene editing- A gene-editing technique is used to edit the genome in which an undesired DNA sequence is removed or a new gene can be inserted into the host genome. CRISPR-CAS9, TALEN and ZFN are some known gene-editing tools used in gene therapy experiments.

Read more:What is gene editing and CRISPR-CAS9?

The genetic engineering technique is used for many different purposes thus we must have to decide first the purpose of the experiment.The entire process of genetic engineering can be divided into 5 broader steps:

The gene must contain a sequence of DNA that we want to study and for that, a gene has some special characteristics. A candidate gene should have high GC content and a lower repetitive DNA sequence.

In addition to this, the gene of interest must not be too long- only a few kb genes can be successfully inserted.Longer the gene higher the chance of failure. The candidate gene must have a start and stop codon in it. Related article:What is The Genetic Code?

Now, the gene of interest can be isolated from the rest of the DNA using either restriction digestion or polymerase chain reaction.

The restriction endonucleases are the bacterial enzyme having the power to digest DNA sequence at a specific location.Using a specific type of restriction endonuclease we can cut and isolated our gene of interest.

The restriction digestion method is explained in our previous article: What is restriction digestion?

In the polymerase chain reaction, using the information of the gene sequence, the gene of interest or the candidate gene is amplified in the thermocycler.

The machine, using the polymerase chain reaction makes millions of copies of a gene of our interest. Through the process of agarose gel electrophoresis, the amplified gene is isolated.

If the gene of interest is well studied, previously, then the information of a gene is accessible in the genetic library and we can use it for the artificial synthesis of a gene of our interest. (using the genetic library information, the gene can also be artificially synthesized)

In the next step, perform DNA purification, if required. Now our DNA is ready to insert in a plasmid.

Selecting plasmid for the genetic engineering experiment is one of the crucial steps in the entire experiment.Before selecting the plasmid, we must understand why the plasmid is used in the gene transfer experiments.

The plasmid DNA is a circular, double-stranded cytoplasmic DNA of the bacteria that replicate independently.

Scientists are using it as a vehicle for transferring the gene of interest to the target location in the genome.It can efficiently transfer the gene at the target location. The structure of plasmid is explained in the figure below,The general structure of the plasmid DNA used in recombinant DNA technology.

Related article: What is a plasmid?

Preparation of plasmid:

Select the plasmid which suits your experiment.

The plasmid must have the origin of replication, promoter region, antibiotic resistance gene and other important sequences.Using the restriction digestion method, an insertion site is introduced in the plasmid at which our gene of interest is ligated.

Utilizing the T4 DNA ligase like power sealer, the DNA of our interest in inserted and ligated in the plasmid.Along with the plasmid, a selectable marker is also introduced in the plasmid DNA to identify the recombinant DNA.

In addition to this, a promoter region and terminator sequences are also included in the plasmid for the effective expression of a gene of our interest. A plasmid with our gene of interest and some other important sequences is now referred to as a recombinant DNA molecule.

Now our recombinant DNA is ready for for the expression.

If we are performing gene cloning than the plasmid is inserted in the bacterial host, for that generally E.Coli are commonly used.Once the bacteria starts dividing, our recombinant plasmid DNA is also replicated along with it.

Now we have the multiple copies of our plasmid DNA which are extracted using the plasmid DNA extraction kit and used for the transformation experiments.The process of Genetic engineering.

Transporting the recombinant DNA into the recipient cell or the host genome is yet another tedious and difficult task.Various methods for recombinant DNA insertion is used for various cell types because a single method cant used for all cell types.

Using stress- bacteria easily uptake the plasmid DNA using some stress factors such as heat or electrical sock.

Microinjection- a sharp needle is used for insertion of DNA directly into the nucleus of a cell, however, the method is less effective and required a higher level of expertise for that.

Electroporation- one of the best methods having a great success rate is the electrophoration method in which the recombinant DNA is inserted into the host genome by permeabilizing the cell with electrical current.

We have covered a whole article on it. Read it here:Electroporation- A Modern Gene Transfer Technique.

Sonication- sonication is yet another good method sometimes used in the gene transfer experiment in which the recombinant DNA is inserted into the target cell using ultrasonic waves. The ultrasonic waves also increase the permeability of cells.

Liposome mediated gene transfer- Using an artificial cell-like outer coat known as a liposome- recombinant DNA can be inserted in the host genome.

Gene transfer using bacterial infection-This method is one of the popular methods and routinely used in plant genetic engineering experiments. Here, the plant species is infected with the transformed bacteria for inserting a gene of interest.

Agrobacterium tumifecian is utilized to insert recombinant DNA into the plant cell. A gene of interest is inserted into the Ti- plasmid of the Agrobacterium. The plant cells are infected by this bacteria cell culture and the transformed cells are regenerated using the plant tissue culture methods.

Chemical in gene transfer- Some metal ions, chemicals, and solutions of different chemicals are also employed in the gene transfer experiments, however, the success rate is too low as compared with the other methods.

Our work is still not completed.

Now we have to conform, whether the recombinant DNA is inserted in our target cell or not. Various molecular genetic technologies are used for that.In the traditional culturing method, the presence or absence of a selectable marker is used to differentiate transformed cells from the untransformed cells.

Although, it is not necessary for the PCR based detection method.The polymerase chain reaction-based detection method is widely accepted more trusted than other methods.

DNA is extracted from the transformed cell and amplified using the primers complementary to our gene of interest or our recombinant DNA.

If the recombinant DNA is present it surely amplified otherwise no amplification obtained. For the two factor conformation, one primer set complementary to recombinant DNA specific and one set of primer complementary to the selectable marker sequence are taken and multiplex PCR is performed.

For validating results, amplification must be obtained in both the reaction.

But wait a minute!

What happened if any mutation occurred during the experiment in our gene of interest? Because the PCR can only amplify the DNA.We must need sequence information to detect the mutation.

For that, the DNA sequencing method is used.

DNA is extracted from the transformed cells and the gene of interest is amplified using the PCR. Now the PCR amplicons are used for DNA sequencing in which using the fluorescent chemistry the sequence of our gene of interest is orderly determined.

Once all the parameters for determining the gene of interest fulfilled, our cells are now ready to inject in the host organism or for tissue culture experiments.

Now coming to the important point of this topic, What is genetic engineering used for?

Genetic engineering has great industrial and agricultural value. It is practiced in medicine, genetic research, agriculture, crop improvement, and for production of therapeutic drugs.

It is also used in the development of genetically modified organisms.Here we are discussing some of the important applications of genetic engineering.

The recombinant DNA technology is used in the crop improvement and development of new economically important traits. Some of them are:

A classical example of it is the BT cotton- one of the types of genetically modified species provides resistance to the plant against bacillus thuringiensis.

Process of developing genetically modified plant species:

A gene of interest is isolated from the organism using restriction digestion or amplified by the polymerase chain reaction.Recombinant DNA is constructed by inserting a gene of interest into the plasmid, here the T- plasmid is used.

In the next step, the T- plasmid is inserted into the agrobacterium.In the last step, the plant species is infected with the transformed bacterial cells and cultured.The entire process of it is shown in the figure below,Agrobacterium-mediated gene transfer in plant species.

GMF- genetically modified food is another best application of genetic engineering in which economically important food products are constructed using recombinant DNA technology.

The classical example of it is Flavr Savr tomato, a genetically modified tomato species made up of the antisense RNA technology.It has great economic values as the GM- tomato can easily be transported from one place to another place.

Another important application of genetic engineering is genetically modified or genetically engineered food.

The quality of some of the food products such as cotton, corn, and soybeans are improved using the present recombinant DNA technology.The aim of developing genetically modified crops or plant species is to make them economical important, nutritious, protein-rich, disease, and stress resistance.

Even, using genetic engineering and tissue culture techniques insecticides resistance plant species in tobacco, potato, corn, and cotton are developed.

In addition to this, some modified plants capable of generating their own fertilizers can also be created using the present genetic modification technique.

Transgenic model organisms are developed to test different parameters- the function of certain genes can be determined by designing the transgenic microorganism and animal models.

Harmful pathogens and insecticidal pasts can be destroyed using genetically modified microorganisms which are capable of degrading toxics.

Medicinal applications:

Low-cost drugs, hormones, enzymes, and vaccines are created using genetic engineering tools.

The anti-blood-clotting factor is the best example of it in which the plasminogen activating enzyme which is capable of dissolving the blood clot is artificially designed and used in the patients with coronary artery disease or heart attack.

Other examples are two other therapeutic proteins somatostatin and lymphokines which are worked against several disease conditions and can be synthesized artificially.Insulin is yet a classic example of a therapeutic protein designed using genetic engineering technology.

A gene for insulin is isolated by restriction digestion or through PCR and inserted int the plasmid.The recombinant plasmid DNA is immediately inserted into the bacterial or yeast cell in which the plasmid is multiplying.As the microorganism starts dividing it starts making artificial insulin.

A large amount of insulin produced using the same technique at an industrial scale. The detailed outline of insulin production is shown in the figure below,Production of insulin using genetic engineering technology.

The commercial production of insulin started after the FDA approval in 1982.

Recombinant vaccines:

Vaccines against smallpox, herpes simplex virus and hepatitis are produced using the genetic engineering technique.The vaccines are the inactivated viral particles used to induce an immune response against that pathogen, however, the chance of contamination is high in it.

Using the recombinant DNA technology scientists has created a unique type of vaccines that only contains the DNA for viral coat protein thus the pathogen can never be activated again.The main advantage of it is that it is safer, contamination-free and more reactive.

Genetic engineering in gene therapy:

Using the gene therapy or gene transfer technique, inherited genetic disorders can be cured. Cystic fibrosis, Duchenne muscular dystrophy and sickle cell anemia like gene therapies are now under the final clinical trial phase and ready to use on patients.

In the gene therapy, a faulty, non-function or mutated gene is replaced with the wild type one using the same technique as explained above.

We have covered amazing articles on gene therapy, read it here:

More:
What Is Genetic Engineering?- Definition, Types, Process And ...

Over the past decade there has been a small cottage industry of published books that address the ethical issues arising from new developments in biotechnology. They cover genetically modified food, transgenic animals, biological weapons, and a subject that accounts for the most volumes, the genetic modification of human beings. As a matter of historical interest, the ethical discussion around creating an uber mensch or in the contemporary jargon, a trans-human or genetically enhanced person, preceded the genetic engineering revolution of the early 1970s. French biologist Jean Rostand's book, Can Man be Modified? was translated into English in 1959.[1] Without knowing anything about cloning or stem cells, Rostand wrote:

If a biologist takes any fragment of tissue from the freshly dead body there is no absolute reason why we should not imagine the perfect science of the future remaking from such a culture, the complete person, strictly identical to the one who had furnished the principle.[2]

Rostand was speculating about the powers of science 50 years into the future and inquiring about the ethical conundrums they would create. Now we are there. In many respects, the science is still ahead of the ethics. Take, for example, the decision of the U.S. Patent & Trademark Office (USPTO) to deny a patent for the production of a chimera by cell fusion that combines the chromosomes of a human and a non-human animal into a viable embryo. The USPTO denied the patent on the grounds that the hybrid organism was too similar to a human being. Even though the chimera had not been created, to be seriously considered, the patent design had to have been sufficiently persuasive so that anyone familiar with the art of making animal chimeras would be able to make the human-animal embryo. While human beings cannot be patented, the processes used to genetically modify humans can be and have been patented. Whether and how those processes should be used is the subject of The Ethics of Genetic Engineering.

Roberta M. Berry has written a creative book on how ethics can inform individual decisions and social policy on human genetic engineering. The book focuses primarily on germline genetic modification. The discussions and analyses are largely aimed at prospective parents who wish to bring into the world a "more perfect" child, not by education or through nurturance of the child's creativity, but by engineering the child's genomes at the point of gestation. Perfection means being more resistant to disease or having other phenotypes that provide more than average advantages in society. Berry applies her skills as a trained philosopher to analyze issues that have been discussed largely by bioethicists in think tanks, university seminars, and professional journals, as well as among NGOs seeking to warn society about the new science of reproductive genetics looming on the horizon.

Whimsically, we might speak about this book as a philosopher's guide to Gattaca, the 1997 film about a future when genetic engineering makes possible the creation of biologically superior humans (known as "valids"), who enter positions of power and prestige.

When the human genome project got underway in the early 1990s and personalized genetics was seen as the next medical frontier, scientists and many bioethicists constructed an ethical firewall between somatic cell and germline gene therapy. The former was seen as a practical extension of drug therapy, although in this case the therapeutics is in the form of genetic materials that are delivered into the patient's cells. Germline gene therapy (or enhancement) was connected to eugenics because it involved planned genetic changes to future generations. This was a short-lived distinction as scientists broke away from any constraints on research. Berry's book, which assumes that germline gene enhancement of humans will eventually take place, prepares readers for new personal and societal choices that will be available to prospective parents. Beyond that the book offers readers a useful exegesis in practical ethics.

The book is divided into five chapters. Chapter 1 offers a broad brushstroke look into the early developments of genetic engineering leading to what the author refers to as "fractious problems", complex and divisive ethical problems resulting from breakthroughs in biomedical science. Chapters 2, 3 and 4 explore how the classical philosophies (utilitarianism, Kantianism, and virtue ethics) provide clarity and wisdom to the ethical choices associated with human germline genetic engineering or the genetic selection of embryos. In Chapter 5 the author explores the viewpoints of modern philosophers including John Rawls, Robert Nozick, Alasdair MacIntyre, Charles Taylor and Ronald Dworkin on changing the genetic architecture of humans. Berry also argues the case that virtue ethics provides the best framework for addressing the issues. "But it does not follow that a utilitarian calculus of welfare maximization or a deontological assessment of duties or rights is well-suited to parental or policy decision-making about revising the genomes of our future children."[3] When science is capable of circumventing the genetic lottery of biological meiosis between sperm and egg, we are faced with new personal and normative reproductive decisions, which become the focus of the book.

There are two qualities that distinguish this book from the pack. First, the author has a richer understanding of ethical theory than most writing in the field of "genome ethics." She uses a broad tapestry of ethical theories as lenses for analyzing problems. And second, Berry applies a creative form of dialogue between one person who personifies a physician, bioethicist and/or genetics counselor and two other individuals who are prospective parents. The dialogues are reminiscent of the Platonic and Galilean dialogues where different philosophical or scientific perspectives appear in the personages who question each other on issues of great public concern. From a teaching standpoint, Berry's dialogues will be useful in reaching students who may have difficulty in applying ethical theory to contemporary problems.

For example, the Kantian counselor explores the parents' right to do whatever is in their power (including genetic modification) to produce a superior child. The counselor says: "Although [your] purpose would be to gain additional opportunities for [your] children, the result of everyone extending their children's lives in an effort to gain a greater share of available opportunities would remain constant and even diminish over time."[4] Applying Kant's Categorical Imperative, the counselor concludes that the prospective parents cannot, without reaching a contradiction to their goals, universalize the maxim "I should act to genetically modify the ovum of my future child to gain additional opportunities." If, for example, height were the phenotype desired, and everyone was afforded the same opportunity to modify the ovum for greater height, there would be no advantage. While this is good Kantianism, it may not convince most people who wish to exercise every available advantage for their children. There are other considerations that are subsumed to the authority of science, namely, that safe genetic modification of the human genome is a myth that, if attempted, is likely to result in dangerous human pathologies.

The conclusion reached by Berry as to how society will resolve the problems brought on by the expected scientific capacity to engineer the human genome is optimistic but philosophically weak. It is based on the faith that a society which devotes itself to virtue (in education and practical life) will use appropriate forms of casuistry to navigate safely through the bramble bush of ethical conflicts. Berry writes that

Virtue ethics invites us to embrace all [ways of understanding] and it trusts that this will enable us to see not just a booming buzzing confusion, but what practical wisdom requires under all the facts and circumstances so we can be as accomplished at acting from the virtues in making choices about genetic engineering as we are in making choices about other practical problems that we confront in daily life.[5]

Some would argue this is what currently exists as we cross the frontier of genetics and reproductive technology, namely ethical and social anarchism.

[1] Jean Rostand. Can Man be Modified? Translated from the French by Jonathan Griffin. New York: Basic Books, 1959.

[2] Rostand, 1959, pp. 13-14.

[3] Robert M Berry. The Ethics of Genetic Engineering. New York: Routledge, 2007, p. ix.

Read more here:
The Ethics of Genetic Engineering | Reviews | Notre Dame ...

Genetic engineering has been a topic of varying contention for years. Recently, though, there was new fuel thrown on the fire with a series of experiments done with Clustered Regularly Interspaced Short Palindromic Repeats or CRISPR. CRISPER is commonly used to refer to a variety of systems that can target specific stretches of DNA allowing scientists to delete particular portions of the genetic code or insert new genetic material into a previously existing genome. The precision of CRISPR allows geneticists to permanently modify an organisms genetic code with previously unheard of accuracy. This technology is based on the naturally occurring abilities of some bacteria.

Even though debate has surrounded genetically engineered crops and genetic experiments in animals, for most people, the controversy surrounding genetic experimentation has been largely ignored. The ethics of genetic engineering, however, are back in the spotlight.

Early this year, a team of scientists successfully performed genetic modification on a fertilized human embryo using CRISPR. In vitro fertilization and gene therapy have involved elements of genetic engineering nearly since their conception, but the CRISPR experiments are the first time humanity has been confronted with human germline genetic modification. Germline modification is used to refer to genetic changes that would be passed down to an organisms offspring. Any genetic alterations done to a parent would appear in children and grandchildren. Naturally, this has once again raised the question of whether genetic engineering is ethical.

Books have been written on the ethics of all sorts of genetic engineering, but the controversy reignited by the CRISPR studies focuses on genetic modification of humans. For decades, accurate and feasible human genetic engineering was something out of a science fiction novel. Depending on a persons opinion on genetic modification, genetically engineered humans were a distant fantasy or specter that loomed centuries down the road.

The CRISPR experiments did not use viable embryos and so no child has resulted from the study, but the CRISPR team proved that genetically modified humans were possible. The ethics of human genetic engineering is no longer a question to be dealt with in some remote future, but a debate that is very relevant now. So, what are the benefits and dangers of human genetic engineering?

Genetic testing is not terribly new. Amniocentesis has been a staple of modern pregnancies for many years, and many at-risk people choose to be tested for genetic diseases such as Huntingtons disease. Improved genetic testing would lead to earlier diagnosis of such diseases. Earlier diagnoses would allow people destined to develop genetic diseases to make the most of their healthy years. Those who did not carry a genetic disease would be able to set their minds at ease.

Human genetic engineering has the potential to do more than identify a faulty gene. Improvements in technologies such as those used in CRISPR have the potential to correct the genetic errors that cause genetic diseases in the first place. Furthermore, germline genetic engineering could lead to the eradication of certain genetic diseases all-together.

Opponents of human genetic engineering argue that some faulty genes actually serve important purposes. The classic example of a useful genetic defect is sickle cell disease. Sickle cell disease, also known as sickle cell anemia, is caused by a genetic flaw that causes some red blood cells to be sickle shaped. The sickle shaped cells are prone to causing blockages in the circulatory system resulting in pain, stroke, cardiac arrest and death. Sickle cell disease, though, only presents if a person carries two copies of the sickle cell gene. If a person only has one copy, they have normal red blood cells and some protection against malaria. Were the sickle cell gene to be universally corrected, malaria-related deaths would increase dramatically.

Critics of genetic modification in humans also point out that genetic engineering is still relatively new. The potential long-term consequences of altering the human genome are still unknown. Changes to the human genetic code could potentially create new genetic diseases or genetic defects that, in the case of germline engineering, would persist for generations.

The specter of designer babies is commonly raised by opponents of human genetic engineering. Advancement in genetic modification techniques could allow parents to influence their childs eye color, hair color, height, intelligence and athleticism. It sounds like something out of a dystopian sci-fi story, but the possibility of designer babies is not as far-fetched as it sounds. Researchers have isolated genes that influence a persons ability to gain muscle mass, and professional athletic associations have struggled to control gene-doping, the non-therapeutic use of cells, genes or genetic elements to enhance performance. Parents can already select the sex of their child in certain areas of the world and, while the genetics of intelligence have not yet been determined, they have long been a topic of interest in the scientific community.

This ability to design a child, genetic engineering critics argue, would lead to a generation of children whose very make-up was shaped by parental whims, market forces, constantly shifting standards of beauty and societal preferences. It could lead to a constantly deepening divide between those who were genetically enhanced or improved and those who were not. This divide might follow current class lines depending on the monetary cost of genetic engineering. This incorporation of a genetic component to the haves and have nots could also lead to a new form of eugenics or even the split of humanity into two distinct species.

Proponents of genetic engineering, however, argue that such claims have little basis in fact. Sex is based entirely on the presence or absence of the Y chromosome while traits such as hair and eye color are controlled by many different genes. Furthermore, the genetics of intelligence are still something of a mystery.

Some genetic diseases have a very high potential of being inherited. A person with Huntingtons disease, for example, has a 50 percent chance of passing the faulty gene on to their child. In such situations, parents may decide not to have children due to a fear of passing on the genetic disorder regardless of how much they wish to have a child. Human genetic engineering has the potential to lower the risks for such couples. Improvements in technology such as CRISPR could allow scientists to correct a faulty gene. Genetic engineering could also be used to lower the dangers of high-risk pregnancies by insuring the genetic health of the fetus.

Those who are against human genetic engineering argue that alternatives exist for parents with a highly inheritable genetic disease. Surrogacy and adoption are options that do not involve invasive changes to an embryos genome.

Opponents of human genetic engineering claim that genetic modification could eventually become a tool of discrimination and prejudice. Researchers have long been curious what genetic predispositions, if any, influence a persons tendency toward anger, violence, hatred and addiction. Genetic tests for such undesirable, but non-medical, traits could lead to discrimination against a person who carried a violence gene, regardless of whether or not the person has ever acted in a violent manner. Furthermore, if genes linked to such social undesirables were found in higher concentrations in certain ethnic groups, racial prejudice would suddenly have a genetic rationalization.

Proponents of human genetic modification argue that genetic testing could be kept confidential to avoid discrimination against individuals. Genetic information would be part of a persons medical record and therefore privileged information.

Despite the potential abuses, those who favor genetic engineering argue that research into genetic influences on violence and addiction should continue. Identifying genetic predispositions towards addiction could help people with a high likelihood of developing a substance abuse problem manage their risks more effectively. Studying genetic links to violence could also lead to the identification of the gene pattern responsible for psychopathy as current research points to the disorder having a hereditary component.

Human genetic engineering has the potential to lead to a longer average lifespan. Researchers have identified the portion of human chromosomes responsible for determining how many times a cell can divide and, thus, how long an organism will live. Human genetic modification could alter this portion of the chromosomes, extending a persons lifespan.

Opponents of human genetic modification point out that the earth is already struggling to support a population of 7.2 billion people. Lengthening the average human lifespan would place even greater stress on an already overburdened planet.

This is one of the most expected controversies in human genetic research. Human genetic experimentation requires the use of human DNA. As with stem cell research, that DNA is usually found in donated eggs, sperm and embryos. This, naturally, runs headlong into the explosive question that has kept the debate over abortion raging for years: when does human life begin?

People who believe that human life begins at conception see the use of fertilized human embryos in medical research, such as the CRISPR study, as abhorrent. To those who hold that life begins at conception, experimentation on a fertilized human embryo is nothing short of sickening violation if not torture.

The use of human embryos in genetic experiments is not universally supported by those who believe that an embryo cannot be considered human until later in development. As of now, embryos used in genetic research are destroyed when the study is complete. This is in part because the scientists working on such research recognize that the long-term consequences of genetic modification are not yet understood. The knowledge required for a woman to safely carry a genetically engineered child to term simply does not exist yet. Still, the waste of human embryos or donated eggs grates on people, especially those who struggle to conceive. Some who rely on fertility treatments or in vitro fertilization see the use of embryos in medical research as a waste of viable eggs.

Proponents of genetic research are quick to point out that the embryos used in the CRISPR experiments were not truly viable. Had any one of the embryos been implanted in a womans womb, the embryo would not have survived to term. Some scientists argue that healthy, viable embryos would not be involved in such genetic modification research until closer to clinical trials. The waste of some viable embryos would be inevitable but would not seriously begin until science was preparing to implant a genetically modified embryo in a woman.

This comes up in nearly every argument involving genetic engineering, regardless of whether it is corn or cows or children being modified. Some people who believe that human beings especially have a right to be unmodified, maintain that altering the human genome is equivalent to playing God. Playing God has a different meaning to every individual with some people claiming than any genetic modification involves a moral and spiritual trespass. On the other side of the spectrum are religious authorities who claim that genetic experimentation is within Gods gift to mankind of dominion over the earth. So far, few religious authorities see the question of genetic engineering as black-and-white. Most allow for genetic engineering that would preserve human life but frown upon the use of genetic modification for non-medically necessary uses such as sex selection.

The ability to select for or against specific traits could affect the genetic diversity of the human species. Opponents of genetic modification argue that germline human genetic engineering would decrease the genetic diversity of the human species as certain traits would be seen as more desirable than others. This decrease in biodiversity would leave the population as a whole more vulnerable to diseases and changes in the environment.

Supporters of human genetic modification argue that genetic engineering could be used to increase genetic diversity. Geneticists could select for traits that would normally be lost in the random shuffle of genes. Human genetic engineering could also theoretically be used to create entirely new traits thus increasing genetic diversity beyond its original starting point.

Regardless of whether human genetic engineering is a marvel or an abomination, the technology to achieve it exists. Human genetic modification is possible and the world knows it. Proponents of human genetic engineering argue that human genetic modification is now inevitable. Someone, somewhere will improve and use the technology. Banning further research, testing and eventual usage would keep the technology from being done in a safe environment. Genetic modification would be driven underground and sold on the black market. Permitting human genetic engineering would also allow organizations to regulate the technologys usage rather than leaving it to become part of the medical tourism industry. Men and women already travel internationally to receive risky surgeries, cheaper pharmaceuticals or procedures illegal in their home countries. The same thing would happen to human genetic modification.

Experiments involving the human genetic modification have revealed information about the human genome that would not have otherwise been discovered. The CRISPR studies, for example, revealed that a human embryo can sometimes repair its own faulty DNA without medical intervention. This phenomenon had never been observed before and scientists had not imagined it was possible. Such discoveries increase geneticists understanding of the human species and genetics as a whole. Further studies of the phenomenon of self-repaired DNA alone could lead to revolutionary treatments for diseases such as Huntingtons, Tay-Sachs and dozens of types of cancer. For proponents of genetic engineering, the information gained through human genetic research is invaluable. Opponents of human genetic modification, however, argue that the ends do not always justify the means.

Both opponents and proponents of human genetic engineering have valid points and strong arguments defending their position. There is a great deal of good to be gained from research into human genetic engineering, but there is also enormous potential for abuse. A genetically engineered human being is not yet safely possible, but the CRISPR studies have taken the concept out of science fiction and planted it squarely in todays reality. What society will decide to do with the potential to modify the human species at its fundamental level has yet to be determined, but the debate over genetic engineering has been reignited, and it suddenly has far more personal consequences for mankind.

The rest is here:
Is Genetic Engineering Ethical | Genetic Engineering Debate ...

Every year between 2004 and 2013, swathes of cabbage grown in fields and greenhouses across New York were attacked by a lethal bacteria that severely wilted the leaves, sometimes making the vegetables appear scorched. For over a century, little was known about this untreatable plant epidemic called black rot, which threatens food security worldwide.

But a group of scientists in Singapore has, for the first time, identified how this "crop killer" bacteria hijack plants at the molecular level and cripple their immune systems.

Their findings will pave the way for plant biologists to better treat infected plants and find ways to rear bacteria-resistant crops without using genetic engineering, said the study's lead, Associate Professor Miao Yansong from Nanyang Technological University's (NTU) School of Biological Sciences.

"For some of the devastating disease in agriculture, the whole field has to be burnt," he said.

Prof Miao and his team found that the black rot-causing bacteria, called Xanthomonas, inject toxic proteins into plant cells. The surface of plant cells contains substances that activate an immune response against diseases.But the toxic proteins form a sticky network, adhering to the cell surface and hijacking the plant's defense mechanisms.

Read the complete article at http://www.straitstimes.com.

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Singapore scientists uncover secret of the black rot in vegetable crops - hortidaily.com

New research by scientists at North Carolina State University (NC State) has demonstrated that genes are capable of identifying and responding to coded information in light signals, as well as filtering out some signals entirely. Their study findings showed how a single mechanism can trigger different behaviors from the same gene. The fundamental idea here is that you can encode information in the dynamics of a signal that a gene is receiving, said Albert Keung, PhD, an assistant professor of chemical and biomolecular engineering at NC State. So, rather than a signal simply being present or absent, the way in which the signal is being presented matters.

The researchers say there are practical applications for their work in the pharmaceutical and biotech sectors. In biomanufacturing, you often want to manage both the growth of cells and the rate at which those cells are producing specific proteins, said Jessica Lee, PhD, research assistant at NC State. Our work here can help manufacturers fine-tune and control both of those variables. Lee is first author, and Keung is corresponding author of the teams published paper in Cell Systems, which is titled, Mapping the dynamic transfer functions of eukaryotic gene regulation, and in which they concluded, This work directly demonstrates thesignal processing potential of a single individual gene and develops molecular and computational tools that can be used to harness it.

There is plenty of evidence that biological information can be encoded in the dynamics of signaling components, and not just in their biochemical identities, the authors noted. This has been implicated in a range of physiological processes, such as the stress response, stem cell differentiation, and oncogenesis. Cells, with a limited number of components, utilize dynamic signal processing to perform sophisticated functions in response to complex environments, the researchers stated. Transcription factors (TFs) may be a particularly important archetype for this typeof information transmission, as they are relatively low in diversity but must command many distinct and complex geneexpression programs.

For their reported study, the researchers developed a platform that combined optogenetics and flow cytometry to map the protein expression response to different dynamic inputs. They modified a yeast cell to express a gene that produces fluorescent proteins when the cell is exposed to blue light. The promoter region of the gene is responsible for controlling the genes activity, and in the modified yeast cells, a specific protein binds to the promoter region of the gene. When blue light is shone on that protein, it becomes receptive to a second protein. When the second protein binds to the first protein, the gene becomes active. And thats easy to detect, because the activated gene produces proteins that glow in the dark.

The researchers exposed these yeast cells to 119 different light patterns. Each light pattern differed in terms of the intensity of the light, how long each pulse of light was, and how frequently the pulses occurred. The researchers then mapped out the amount of fluorescent protein that the cells produced in response to each light pattern.

We may tend to think of genes being turned either on or off, butless like a light switch and more like a dimmer switcha gene can be activated a little bit, a lot, or anywhere in between. So, if a given light pattern led to the production of a lot of fluorescent protein, that meant the light pattern made the gene very active. If the light pattern led to the production of just a little fluorescent protein, that meant the pattern only triggered mild activity of the gene.

We found that different light patterns can produce very different outcomes in terms of gene activity, said Lee. The big surprise, to us, was that the output was not directly correlated to the input. Our expectation was that the stronger the signal, the more active the gene would be. But that wasnt necessarily the case. One light pattern might make the gene significantly more active than another light pattern, even if both patterns were exposing the gene to the same amount of light.

The researchers found that all three light pattern variablesintensity of the light, frequency of the light pulses, and how long each pulse lastedcould influence gene activity, but they also found that controlling the frequency of light pulses gave them the most precise control over gene activity.

We also used the experimental data here to develop a computational model that helped us better understand why different patterns produce different levels of gene activity, said Leandra Caywood, co-author of the paper and a PhD student at NC State. For example, we found that when you bunch rapid pulses of light very closely together, you get more gene activity than you would expect from the amount of light being applied. Using the model, we were able to determine that this is happening because the proteins cant separate and come back together quickly enough to respond to every pulse. Basically, the proteins dont have time to fully separate from each other between pulses, so are spending more time connected meaning that the gene is spending more time activated. Understanding these sorts of dynamics is very useful for helping us figure out how to better control gene activity using these signals.

Our finding is relevant for cells that respond to light, such as those found in leaves, Keung added. But it also tells us that genes are responsive to signal patterns, which could be delivered by mechanisms other than light.

So how might this work in cells? A cell may receive a chemical signal. The presence of the chemical cant be patternedits either present or it is not. However, the cell can respond to the presence of the chemical by creating a patterned signal for the target gene. The cell does this by controlling the rate at which the protein that binds to the promoter region enters and exits the nucleus of the cell. We could think of controlling the presence and absence of this protein as sending a Morse code message from the cell to the gene. Depending on a suite of other variablessuch as the presence of other chemicalsthe cell can fine-tune the message it sends to the gene in order to modulate its activity.

This tells us that you can use the same protein to give different messages to the same gene, Keung said. So the cell can use one protein to have a gene respond differently to different chemicals.

In a separate set of experiments, the researchers found that genes were also able to filter out some signals. The mechanics of this are both straightforward and mysterious. The researchers could tell that when a second protein attached to the promoter region of the gene, some frequencies of light pulses did not trigger the production of fluorescent proteins. In short, the researchers know the second protein ensured that a gene responds only to a specific suite of signalsbut they dont know exactly how the second protein accomplishes that.

The researchers also found that they could control the number of distinct signals a gene could respond to by manipulating the number and type of proteins attached to the promoter region of the gene.

For example, you could attach proteins to the promoter region that serve as filters to limit the number of signals that activate the gene. Or you could attach proteins to the promoter region that trigger different degrees of activation of the gene.

One additional contribution of this work is that weve determined we can communicate about 1.71 bits worth of information through the promoter region of a gene with just one protein attachment, Lee said. As the authors explained, This system revealed tunable gene expression and filtering behaviors and provided a quantification of the limit to the amount of information that can be reliably transferred across a single promoter as ~ 1.7 bits. Lee continued, In practical terms that means that the gene, without a complex network of protein attachments, is able to distinguish between more than three signals without error. Previous work had set that baseline at 1.55 bits, so this study advances our understanding of whats possible here. Its a foundation we can build on.

The researchers say their work will enable future studies that help scientists to understand the dynamics of cell behavior and gene expression. This work directly demonstrates the signal processing potential of a single individual gene and develops molecular and computational tools that can be used to harness it, they wrote. There are many avenues to expand into and explore. In our work, we relied on endpoint measurements that could be rapidly measured by flow cytometry. However, information can also be stored in the dynamics of the output signal, e.g., the production rate, time delay of repression/activation, or oscillatory behavior. High throughput approaches that can track the output dynamics of thousands of cultures would unlock this potential space for investigation.

And while the reported study focused on a single promoter, different promoter structures would likely confer distinct transfer functions, the investigators further noted. Continued advances in experimental and computational systems that can handle the large parameter space of dynamic signals will unlock our ability to measure, quantify, and understand information transmission in biological systems and reveal the underpinnings of how limited numbers of components can give rise to the rich complexity of biological functions.

Original post:
Findings Show Gene Behavior Depends on Coded Info in Signals and Could be Harnessed to Fine-Tune Biotech - Genetic Engineering & Biotechnology...