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BPSC Mains GS-2 Masterclass · Science & Technology

Genetic Engineering & CloningGenes, Clones, DNA Profiles & Blood Groups

Scientists can now cut, copy and move genes between species. This page explains genetic engineering and how far it can cure inherited disease, what cloning is and why it divides opinion, how a DNA fingerprint identifies a person, and how blood groups decide who can give blood to whom.

MethodrDNARecombinant DNA

genes from many sources joined.

CRISPR2018Gene-edited babies

made with CRISPR in China.

Cloning1996Dolly the sheep

the cloned sheep.

IndiaCDFDHyderabad

India's DNA fingerprinting centre.

Blood36 / 346Blood group systems / antigens

recognised by ISBT.

TransfusionO & ABDonor and recipient

universal donor and receiver.

Part 1 · What is genetic engineering?

Genetic Engineering: Rewriting an Organism's Genes

The direct manipulation of genes, moving them within and across species with recombinant DNA, to make improved or novel organisms.

Illustration of a DNA double helix being cut and joined by molecular scissors, with a lab bench, petri dishes and a pipette

Genetic engineering

Genetic engineering, also called genetic modification or genetic manipulation, is the direct manipulation of an organism's genes using biotechnology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms.

New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by artificially synthesising the DNA.

GMOs

An organism that is generated through genetic engineering is considered to be genetically modified (GM) and the resulting entity is a genetically modified organism (GMO). GM crops are modified to increase resistance to insects and herbicides.

Genetic engineering has been applied in numerous fields including research, medicine, industrial biotechnology and agriculture.

Recombinant DNA

Recombinant DNA (rDNA) molecules are DNA molecules formed by laboratory methods of genetic recombination to bring together genetic material from multiple sources, creating sequences that would not otherwise be found in the genome.

Example: Think of DNA as a recipe book. Recombinant DNA is like cutting a recipe out of one book and pasting it into another: the human insulin 'recipe' pasted into a bacterium's book makes the bacterium cook insulin.

Part 2 · How far can it be used to treat genetic illness?

How Far Can Genetic Engineering Treat Genetic Illness?

By making drugs, building animal models of disease, and through gene therapy and genome editing, with three-parent babies and COVID-19 vaccines as recent examples.

Drugs

Manufacturing of drugs, creation of model animals that mimic human conditions and gene therapy.
- One of the earliest uses of genetic engineering was to mass-produce human insulin in bacteria.
- It is applied to human growth hormones, follicle stimulating hormones (for treating infertility), vaccines and many other drugs.

Animal models

Genetic engineering is also used to create animal models of human diseases. Genetically modified mice are the most common genetically engineered animal model.
- They have been used to study and model cancer (the oncomouse), obesity, heart disease, diabetes, arthritis, substance abuse, anxiety, aging and Parkinson disease.
- Potential cures can be tested against these mouse models.
- Also genetically modified pigs have been bred with the aim of increasing the success of pig to human organ transplantation.

Gene therapy

Gene therapy is the genetic engineering of humans, generally by replacing defective genes with effective ones.
- Clinical research using somatic gene therapy has been conducted with several diseases, e.g. Parkinson's disease.
- In 2015 a virus was used to insert a healthy gene into the skin cells of a boy suffering from a rare skin disease in order to grow, and then graft healthy skin onto 80 percent of the boy's body which was affected by the illness.

Further uses against disease

A Chinese doctor using CRISPR technology produced genetically altered babies in 2018.
Using the gene therapy or gene transfer technique, inherited genetic disorders can be cured. Cystic fibrosis, Duchenne muscular dystrophy and sickle cell anaemia like gene therapies are now under final clinical trial phase and ready to use on patients.
In research GMOs are used to study gene function and expression through loss of function, gain of function, tracking and expression experiments.
Producing hormones, vaccines and other drugs, genetic engineering has the potential to cure genetic diseases through gene therapy.
Can be used to produce drugs.
The anti-blood-clotting factor is a great example of it in which 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.
Human genome editing can be used to treat many human diseases & genetic disorders like HIV/AIDS, haemophilia etc.
- DNA-plasmid vaccines are in early-stage clinical trials for viral illnesses, like rabies, HIV and Zika.
It could substantially bolster disease resistance in humans & increase life span.
It could form the basis of highly efficient & cost effective next generation antibiotics (based on bacteriophage viruses).
Gene editing can be used to protect endangered species or bring to life extinct species.
It can be used to grow healthier food (via fortification) and increasing harvest.
It has the potential to slow down the spread of diseases by eliminating its means of transmission, e.g. Gene editing can be used to introduce sterile mosquitoes into the environment.

Mitochondrial Replacement Therapy: the 3-parent baby

Three-parent baby is human offspring produced from the genetic material of one man and two women through the use of assisted reproductive technologies. Here the mitochondrial DNA from the donor women is used by discarding the mother's faulty Mitochondrial DNA.

COVID-19

Some researchers have suggested that Genetic Engineering will help quickly create potential vaccines against COVID-19.
- Researchers are using genetic engineering rather than traditional methods, which can take years.
- The genome of Covid-19 is similar to that of the coronavirus that caused the 2003 SARS outbreak, yet it also had striking differences.

Part 3 · Other applications and limitations of genetic engineering

Beyond Medicine, and the Limits of Gene Editing

Conservation, microbial art and blue roses on one side; designer babies, off-target edits, gene drives, regulation and cost on the other.

Other applications

Genetic engineering has potential applications in conservation and natural area management. Gene transfer through viral vectors has been proposed as a means of controlling invasive species as well as vaccinating threatened fauna from disease.
- Transgenic trees have been suggested as a way to confer resistance to pathogens in wild populations.
- With the increasing risks of maladaptation in organisms as a result of climate change and other perturbations, facilitated adaptation through gene tweaking could be one solution to reducing extinction risks.
- However, applications of genetic engineering in conservation are thus far mostly theoretical and have yet to be put into practice.
Genetic engineering is also being used to create microbial art.
Some bacteria have been genetically engineered to create black and white photographs.
Novelty items such as lavender-colored carnations, blue roses, and glowing fish have also been produced through genetic engineering.

Limitations of gene engineering

There are ethical issues associated with the use of gene therapy and genetically engineered products.
- Concerns over ‘Designer Babies’: Engineering human embryos raises the prospect of designer babies, where embryos are altered for social rather than medical reasons e.g. to increase height or intelligence.
To provide an economic value to the food product or any GM product, the nutritional values are compromised.
Because of the adverse effect of it, new resistant pathogenic strains are evolved faster.
Balance Risks & Benefits: Due to the possibility of off-target effects (edits in the wrong place creating properties different from those that were intended) and Mosaicism (when some cells carry the edit but others do not, leading to presence of two or more populations of cells), safety is of primary concern.
Ecological impacts: A ‘gene drive’ can propagate a set of genes with negative traits throughout a population which may lead to disappearance of whole targeted population with severe ecological consequences.
Difficulty in regulation: The precise genetic modifications obtained through CRISPR Cas9 technique makes it more difficult to identify a genetically modified organism once outside the lab and also to regulate such organisms in the market.
Uncontrolled clinical trials: There are at present no standard norms for standardisation of norms for clinical trials for checking the efficacy of the treatment.
The technology is costlier as gene therapy cost up to 50,000 USD.

Conclusion

Playing with the embryo or fetus is against the natural law, people strongly believe in it, thus genetically modified food and plant products are always becoming a centre of controversy. However, using genetic engineering tools such as gene therapy and gene transfer technique, inherited disorders and cancer like lethal diseases can be prevented. Positive use of genetic engineering techniques can change the fate of mankind.

While using Gene engineering we should focus on transparency, Equity, Promoting Wellbeing. Bodies assigned with genetic engineering regulation like Institutional Biosafety Committee, Review Committee on Genetic Manipulation and Genetic Engineering Approval Committee have critical role to play here.

Part 4 · What is cloning? Its scientific merits and demerits

Cloning: Making Genetic Copies

Nature clones all the time; science can now clone genes, cells and whole animals, which brings real benefits and serious worries.

Cloning

Cloning is the process of producing individuals with identical or virtually identical DNA, either naturally or artificially.

In nature, many organisms produce clones through asexual reproduction, e.g. reproduction method used by plants, fungi, and bacteria, and is also the way that clonal colonies reproduce themselves.

Cloning in biotechnology refers to the process of creating clones of organisms or copies of cells or DNA fragments (molecular cloning).

Merits

Genetic cloning is done to create a desired gene from DNA to ensure certain qualities.
It helps infertile couples to bear children, e.g. 3-parent baby.
It has great contribution to organ replacement.
- Genetic cloning allows scientists to take small amounts of cells from a certain organ and use them to generate and harvest new organs that are entirely functioning.
It allows for growing eminent individuals.
- Theoretically, someone like Martin Luther King Jr. or Albert Einstein can be brought back to life by cloning. This means we will be able to have such knowledgeable individuals to educate and help people in today's world.
Cure for Diseases.
It naturally occurs in nature, by various plants, bacteria etc.
- Parts of an individual plant may become detached by fragmentation and grow on to become separate clonal individuals, e.g. moss and liverwort gametophyte.
Cloning is used in horticulture, and agriculture.
- Grafting can be regarded as cloning, since all the shoots and branches coming from the graft are genetically a clone of a single individual.
- Cloning high yielding varieties of seeds.

Demerits

Critics say that it is morally inappropriate to manipulate nature.
It comes with a degree of uncertainty as of yet. The repercussions and effects of cloning remain unknown to date.
It might lead to problems in organ rejection. There may be a substantial difference in the cell make-up between the original and replicated organ.
It decreases gene diversity.
- The ability of humans to live greatly relies on the diversity of genes, which comes from parents who have different sets of genes. One big disadvantage of identical genes is that they will weaken our adaptations and power, which can make us subjected to certain diseases easily.
The beauty of humanity lies in the differences among individuals, and cloning ruins this.
In-Breeding: One of the most unfavorable consequences of cloning is in-breeding, where everyone will be having the same genotypes, which can keep reproducing among themselves, sowing the seeds of our own destruction.
One of the main drawbacks of cloning is that if the original organism has genetic defects:
- Dolly the sheep, born to a surrogate in 1996, was a genetic copy of a six-year old sheep. Dolly only lived to six years old herself, the bottom end of a sheep's average life expectancy.
Unbalance to the Society: Many people think that it is ridiculous to separate reproduction from love and other human relationships, thus cloning may give rise to social side effects.
Can increase inequality in the society.
The risk of being abused: e.g. imagine what a corrupt dictator could do with cloning.

Need for regulation

Today, it is done in the real world and is one of the most controversial topics within the medical and scientific communities. There is need for better regulation so that its negative impact can be avoided.

Part 6 · Short note: blood groups

Blood Groups, Transfusion and the Rh Factor

Antigens on red cells and antibodies in plasma decide a person's blood group, who can donate to whom, and why the Rh factor matters.

Blood groups

The blood groups are a classification of blood, based on the presence and absence of antibodies and inherited antigenic substances on the surface of red blood cells (RBCs). These are inherited and represent contributions from both parents.

A total of 36 human blood group systems and 346 antigens are now recognized by the International Society of Blood Transfusion.

Antigens and antibodies

The main reason behind the difference in blood of human is the glycoprotein which is found in Red Blood Corpuscles called antigen. Antigens are of two types: Antigen A and Antigen B.

An opposite type of protein is found in blood plasma. This is called antibody. This is also of two types: Antibody ‘a’ and Antibody ‘b’.

The four blood groups

On the basis of presence of antigen (glycoprotein), there are four groups of blood in humans. With the four groups of blood, the division of antibody is as under:

Blood group	Antigen (in red blood corpuscles)	Antibody (in plasma)
A	Only ‘A’	Only ‘b’
B	Only ‘B’	Only ‘a’
AB	Both ‘A’ and ‘B’	Absent
O	Absent (neither antigen)	Both ‘a’ and ‘b’

Blood transfusion

Antigen ‘A’ and antibody ‘a’, Antigen ‘B’ and antibody ‘b’ cannot live together. In case this happens, they become very sticky, which spoils the blood. This is called agglutination of blood.
Therefore, in blood transfusion adjustment of Antigen and Antibody should be done carefully so that agglutination of blood does not take place.
Blood Group O is called Universal Donor because it does not contain any antigen.
Blood Group AB is called Universal Recipient because it does not contain any antibody.

Rh factor

Rh factor: It is a different type of antigen in the blood. The person in whose blood it is found has Rh-positive blood, and the person in whose blood it is not found has Rh-negative blood.

At the time of blood transfusion Rh-factor is also tested. Rh+ is given to Rh+ and Rh- is given Rh- blood only.
If the blood of Rh+ blood group is transferred to a person with Rh- blood group, then due to the less quantity for the first time there does not seem any bad effect but if this process is repeated then due to agglutination the person with Rh- blood group dies.
- e.g. Erythroblastosis Foetalis: If the father's blood is Rh+ and the mother's blood is Rh- then the child to be born dies at the pregnancy or short span of time after the birth.

Expected blood group of the child

Based on the blood group of parents the child's blood group can be expected, e.g.:

Mother × father	Expected blood group of child
O × O	O
O × A	O, A
A × A	O, A
AB × AB	A, B, AB

“Positive use of genetic engineering techniques can change the fate of mankind.”

— BPSC Mains answer · Genetic engineering

Curated for BPSC, UPSC & State PCS Civil Services Aspirants | Science & Technology Master Module

Explore More Beyond the Book Modules

Genetic Engineering & CloningGenes, Clones, DNA Profiles & Blood Groups

Genetic Engineering: Rewriting an Organism's Genes

How Far Can Genetic Engineering Treat Genetic Illness?

Drugs

Animal models

Gene therapy

Further uses against disease

Mitochondrial Replacement Therapy: the 3-parent baby

COVID-19

Beyond Medicine, and the Limits of Gene Editing

Other applications

Limitations of gene engineering

Cloning: Making Genetic Copies

Merits

Demerits

DNA Fingerprinting and India's Pioneers

Uses

Research institutions in India working in this area

Blood Groups, Transfusion and the Rh Factor

The four blood groups

Blood transfusion

Rh factor

Expected blood group of the child

BPSC Mains Previous Year Questions

Define ‘Genetic Engineering’. How far can it be used to treat genetic illness?

Write short notes on Genetic Engineering.

What is cloning? Write the scientific merits and demerits of cloning.

What is ‘DNA finger printing’? Which research institution in India is working in this area?

Write short notes on Blood Groups.