< General Studies Home Page

Content

1.  GM Crops
2.  Reduced Height Genes (Rht): Advantages and Limitations
3.  Biotechnological Application in Medicines
4.  Transgenic Animals
5.  Biotechnology and Environment
6.  GM INsects

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1) GM Crops

• GM Crops, Advantages and Controversies
  • Crops whose DNA has been altered are known as GM crops. This genetic modification of crops can add or remove certain characteristics from the plant and thus can bring many advantages.
    • Make crops more tolerant to anti-biotic stresses (cold, drought, salt, heat) etc. E.g., GM Rubber developed by Rubber Research Institute of India
    • Make plants Pest Tolerant.
      • Reduces reliance on chemical pesticides.
      • E.g. BT cotton, BT Brinjal (in Bangladesh)
    • Help to reduce post-harvest losses
    • Enhance the nutritional value of food, e.g., Golden Rice (Vitamin A enriched rice)
    • Tailor-made plants to supply alternative resources to industries, in the form of starches, fuels, and pharmaceuticals.

A) BT Cotton

• Specific BT Toxic gene (cry1Ac) were isolated from Bacillus thuringiensis and incorporated into several crop plants such as cotton. This produces proteins that kill certain insects such as lepidopterans (tobacco budworm, armyworm), beetles, etc.
• It has been grown in India since 2002 and over the years have given increase productivity and area under crop cultivation. It has also led to decrease in insecticide which fought bollworms by 97%.
• But it has also raised concerns like increased water consumption, and emergence of pesticide resistant pests (e.g., pink bullworm), and increased use of insecticide for controlling pests like sucking pests.

B) BT Brinjal

• Transgenic Brinjal created by inserting a crystal protein gene (Cry1Ac) from the soil bacterium Bacillus thuringiensis into the genome of various brinjal cultivar. It gives resistance against lepidopteron insects in particular the Brinjal fruit and shoot border (BFSB), the most common pest which affects 30-50% of the Brinjal crops.
• The crop also cleared the GEAC’s biosafety test in 2009. But government yielded to anti-GM activists and declared a moratorium in 2010 on the crop.
• But some cases of illegal BT Brinjal cultivation were observed in Haryana in 2019
• Why are some groups calling for allowing of BT Brinjal in India?
  • It had cleared the GEAC’s biosafety test in 2009.
  • Increased benefit for farmers: Popular all over the world. In Bangladesh studies shows zero borer infestation which has led to cut in input pesticide use by 60%.
  • When GM Crops are not officially available, farmers turn to unapproved knock offs that may not conform to accepted biosafety standards.
• Why is BT Brinjal not allowed in India? Why is it opposed by various activists?
  • There are fears that it may impact India’s plant biodiversity. India has more than 3,000 natural varities of Brinjal and activists are worried that if BT Brinjal is allowed in India all varieties will be contaminated.
  • Further, cross pollination may lead to herbicide resistant super weeds that can further threaten environment and biodiversity.

• Health Impact is something that needs to be studied more.
• Not so obvious benefits: A recent study from surveys of farmers indicate that 2/3^rd of the farmers who moved to BT Brinjal have had a ‘bad’ or ‘very bad’ experience.

C) GM Mustard

• What is GM Mustard?
  • DMH-11 (Dhara Mustard Hybrid) is a genetically modified (GM) mustard Hybrid.
  • GM mustard is the country’s first genetically modified food crop.
  • It was developed by a team of scientists led by former Vice Chancellor Deepak Pental, of DU at Center for Genetic Manipulation of Crop Plants (CGMCP), Delhi University by crossing Indian mustard cultivars with juncea lines of East European origin like ‘Early Heera’ and Donskaja.
• Claim of higher yield:
  • Claims around 30% more yield than the traditional varieties
• What genetic modification was achieved and what are its benefit?
  • Barnase gene and Barster gene from Bacillus amyloliquefaciens
    • Barnase impairs pollen production
    • Barster blocks the function of Barnase
    • Hybridization becomes possible:
    • This method was used to developed DMH-11 by crossing a popular Indian mustard variety ‘Varuna’ (the barnese line) with an East European ‘Early Heera-2’ mutant (barstar).
• Arguments for and against approval of GM mustard
  • For
    • Higher Production
    • Reducing Import Dependency
    • Saving Forex
    • Keeping India Scientifically relevant
  • Against
    • The main contention is that the GM mustard incorporates three alien genes – barnase, barstar, and bar – rendering it inherently unsafe for human and animal health.
      • But these genes have already been deployed in Canola, and we import it freely.
      • Mustard is a food crop unlike cotton, so both should not be compared
      • All health effects not properly known yet
      • Environmental damages should be studied properly first.
      • Yield claims have been challenged by many organizations=
• GEAC Approval (Oct 2022)
  • In Oct 2022, GEAC approved commercial cultivation of genetically modified mustard yet again. The approval allowed environmental release of two varieties of genetically engineered mustard, so that it can be used for developing new parental lines and hybrids under the supervision of ICAR. The environmental release of DMH-11 will allow for its seed production and testing as per existing ICAR guidelines and other extant rules/ regulations prior to commercial release. The field demonstration studies on the effect of GE mustard on honeybees and other pollinators was also allowed to be conducted.

D) GM RUBBER – Developed by Kerala based – Rubber Research Institute of India

• Rubber Research Institute of India have developed a plant tailored for the climatic conditions in the Northeast.
• Rubber board research farm at Sarutari on the outskirts of Guwhati now sports world’s first GM rubber plant, tailored for climatic condition in the north-east.
• Genetic Modification: The GM rubber has additional copies of the gene MnSOD, or manganese-containing superoxide dismutase, inserted in the plant, which is expected to tide over the severe cold conditions during winter – a major factor affecting the growth of young rubber plants in the region.

E) INCREASING THE NUTRIENT CONTENT – GOLDEN RICE

• Golden Rice 
  • What is Golden Rice?
    • The IRRI and its national research partners have developed golden rice to complement existing interventions to address vitamin A deficiency (VAD). It is a serious public health problem affecting millions of children and pregnant women globally.
    • Golden rice is variety of rice produced through genetic engineering to biosynthesize beta-carotene. Beta-carotene is a nutrient similar to what is found in orange colored fruits and vegetables and is converted into Vitamin-A as needed by the body.
    • Thus, golden rice can help south and south-east Asian countries, where two-thirds or more of daily calorific intake is obtained from rice. Research has indicated that the golden rice can provide upto 50% of the daily requirement of an adult for vitamin A.

• • • Goldenricewasoneofthe 7winnersofthe2015Patentsfor Humanity Awardsby the United States Patent and Trademark Office

• Safety Evaluation by International Rice Research Institute
  • The safety evaluation of Golden rice has shown that it is as safe and nutritious as conventional rice but comes with added benefit of beta-carotene.
• About International Rice Research Institute:
  • IRRI is the world’s premiere research organization dedicated to reducing poverty and hunger through rice science; improving the health and welfare of rice farmers and consumers; and protecting the rice growing environment for future generation.
  • It is an independent, non-profit, research and educational institute, founded in 1960 by the Ford and Rockefellar foundations with support from the Phillipines government.
  • The institute is headquartered in Los Banos, Philippines and has offices in 17 rice-growing countries in Asia and Africa.
  • It works with in-country partners to develop advanced rice varieties that yield more grain and better withstand pests and disease as well as flooding, drought, and other harmful effects of climate change.

F) Issue of Illegal cultivation of GM Crops:

• BT Brinjal Illegal cultivation in Haryana Rajasthan etc
• Sale of Illegal HTBt (Herbicide tolerant Bt) cotton seeds has doubled this year(June 2021)
  • The HTBt cotton variant adds another layer of modification to BT cotton, making the plant resistant to the herbicide glyphosate, but has not been approved by regulators.
  • Support for HTBt: Groups like Shetkari Sangathan are demanding the legalization of HTbt cotton.
    • Saves cost: Weeding labour cost reduces, only one round of glyphosate spraying is needed to deal with the weed.
    • Illegal sales reduce accountability, hampers government revenue and farmers are at risk of getting wrong information.
  • Concerns/Fears:
    • Glyphosate have carcinogenic effect
    • Unchecked spread of herbicide resistance to nearby plants through pollination, creating a variety of superweeds etc.

G) SCIENTISTS ARE ENGINEERING PLANTS TO PRODUCE INSECT ‘SEX PERFUME’ TO REPLACE PESTICIDES (APRIL 2023)

• Researchers areengineering tobacco plantstoproduce mothpheromonesthat couldpotentially be used to create traps that can lure insects as a replacement for harmful pesticides.
• Note: Pheromones are chemicals that are produced and released by animals. When they are released by an individual of a species, they effect the behaviour of other individuals. Animals secrete these pheromones to trigger different kinds of behaviour. The pheromones that trigger sexual arousal can be thought of as a kind of ‘sex perfume’, attracting other individuals of the same species.
• The researchers engineered plants to produce chemicals that mimic these pheromones.
• Note:
  • Chemically produced insect pheromones are already used for pest control and have been for some decades. Some insect traps contain pheromones to attract the insect to them, for use in the house garden, and in food production systems.
  • Disadvantages of these chemically produced pheromones: It is not possible to make complex pheromones by this mechanism. Moreover, chemical manufacturing process produces a number of other pollutants.
• GM Crop Route:
  • Researchers used Nocotiana benthamiana, a species of tobacco.
  • Note: The same plant has been engineered to produce ebola antibodies and even coronavirus like particles for use in COVID vaccine.
  • Here, scientists built a sequence of DNA in the lab that mimic moth’s genes and also put in place a few molecular switches that can precisely regulate how the molecules are formed. The switches can turn the manufacturing process on and off.
• Advantages of using pheromones: They are highly species specific and unlike broad spectrum pesticides don’t kill other species of pollinators.

2) REDUCED HEIGHT GENES (RHT): ADVANTAGES AND LIMITATIONS

Introduction

• Since the 1960s and the Green Revolution, reduced height (Rht) genes have increased global yields because the short-stemmed wheat they produce puts more investment into the grains rather than into the stems and has improved standing ability. It leads to reduced risk of lodging, increase in partitioning and assimilation of grains, more fertile florets per spriklet and higher harvest index (the proportion of plant weight in grains).
• The high yielding wheat variety developed by Borlaug, which required higher use of fertilizers and pesticides, produced bigger grains. However, the heavier grains caused the plants to become unstable and prone to lodging. Therefore, Borlaug introduced dwarfing genes into wheat giving plants a stronger, shorter stem that resisted lodging.
  1. 21 reduced height genes in wheat Rht1 – Rht21, have been described so far.
  2. In India, the presently available semi-dwarf varieties, which were explored during the Green Revolution, carry conventional Rht1 dwarfing alleles (variant form of a given gene) and produce optimum yields under high-fertility irrigated conditions.
• Limitations of Dwarf wheats:
  • Dwarf wheats are not well adapted to deeper sowing condition This is due to shorter coleoptiles, and low early vigor often results into reduced seedling emergence. Further shorter coleoptiles lead to crop residue posing a problem for seedling emergence.
  • These wheats also don’t work in drought conditions they can’t be planted deep inside the soil to access moisture. They will fail to reach the surface of the soil.
• Key Research to solve the issue:
  • Scientists at Agharkar Research Institute (ARI), an autonomous institute of DST, have mapped to alternative dwarfing genes of Rht14 and Rht18. These genes are associated with better seedling vigor and longer coleoptiles (sheath protecting the young shoot tip).
  • Advantages:
    • The new wheat variety will be suitable for sowing under rice stubble retained condition and in dry environments. It would thus reduce the need of water and also contribute to reduction in crop stubble burning.
    • It also diversifies the genetic base of dwarfing genes considering diverse wheat growing zones in India.
• Recent research published in the Proceedings of the National Academy of Sciences (PNAS) journal on 23rd Nov 2022 says that Scientists at the John Innes Centre, in collaboration with an international team of researchers, have discovered the new “reduced height” or semi dwarf gene called Rht13. The varieties of wheat with Rht13 gene could be rapidly bred into wheat varities to enable farmers to grow reduced-height wheat in drier soil conditions.

Rht13 overcome this problem of seedling emergence because the gene acts in tissues higher-up in the wheat stem. So, the dwarfing mechanism only takes effects once the seedling has fully emerged. This gives farmers a significant advantage when planting deeper in dry conditions.

3) BIOTECHNOLOGICAL APPLICATION IN MEDICINES

The recombinant DNA technological processes have had a great impact in the area of health care by enabling mass production of safe and more effective therapeutic drugs.

• • Further, the recombinant therapeutics do not induce unwanted immunological responses as is common in case of similar products isolated from non-human sources.
  • At present, more than 30 recombinant therapeutics have been approved for human-use the world over.
    • In India, around 12 of these are presently being marketed.

A) VACCINES (COVERED SEPARATELY WITH HEALTH SECTION)

• For e.g.,various vaccinesfor COVID-19weredeveloped with thehelp of biotechnology –mRNA vaccines, vaccines with attenuated virus

B) MASS PRODUCTION OF EFFECTIVE THERAPEUTICS

• The recombinant DNA technological processes have had a great impact in the area of health care by enabling mass production of safe and more effective therapeutic drugs.
• Advantages of recombinant therapeutics: Further, the recombinant therapeutics do not induce unwanted immunological responses as is common in case of similar products isolated from non-human sources.
• At present, more than 30 recombinant therapeutics have been approved for human-use the world over.
• In India, around 12 of these are presently being marketed

C) GENETICALLY ENGINEERED INSULIN

• Earlier, Insulin used for diabetes was extracted from pancreas of slaughtered cattle and pigs.
• Caused patients to develop some kind of allergies or other kinds of reactions to the foreign protein.
• Structure of Insulin
  • Insulin consists of two short polypeptide chains: Chain A and Chain B, that are linked together by disulphide bridges.
  • In Mammals, including humans, insulin is synthesized as a pro-hormone (like a pro-enzyme, pro hormone also needs to be processed before it becomes a fully mature and functional hormone) which contains an extra stretch called C peptide.
  • This C peptide is not present in the mature insulin and is removed during maturation into insulin.
• The main challenge for production of insulin using rDNA technique was getting insulin assembled into a mature form.
• How this was achieved through Biotechnology
  • In1983,Eli Lillyan American company prepared two DNA sequences corresponding to A and B, chains of human insulin and introduced them in plasmids of E. coli to produce insulin chains.
  • Chains A and B were produced separately, extracted and combined by creating disulphide bonds to form human insulin.

 

 

D) GENE THERAPY

Introduction

If a person is born with a hereditary disease, can a corrective therapy be taken for such disease? Gene therapy is an attempt to do this.

Gene therapy refers to the process of introduction, removal or change in the content of an individual’s genetic material with the goal of treating the disease and a possibility of achieving long term cure.

Gene Therapy Products (GTPs) include the mechanisms to deliver nucleic acid components by various means for therapeutic benefit to patients. They include entities that are used for things like gene augmentation, gene editing, gene silencing, synthetic or chimeric gene augmentation etc.

Note: Not all medical procedures that introduce alterations to a patient’s genetic makeup can be considered a gene therapy. For e.g.: Bone Marrow transplantation and organ transplants in general have been found to introduce foreign DNA into patients.

Advantages of promoting gene therapy

• Permanent treatment for genetic diseases: the therapeutic approach earns the advantage of being long lasting, sometimes permanent result.
• High burden of rare genetic diseases in India: Around 7 core of India’s population suffers from rare genetic diseases. Gene therapy can prove to be a turning point in treatment of such genetic diseases.
• Worldwide market of upto $250 billion by 2025; continuous scope of medical tourism.
• In USA and Europe, the approval of several gene therapy products in USA and EU have paved the way for development of therapies for a variety of previously untreatable disorders. The guidelines should help in development and fast tracking of approval of such GTPs in India too.

Concerns/Limitations

• Promotion of development of gene therapy also brings along with it unique technical risks and ethical challenges.

Technical Challenges

• The gene therapy may be associated with unwanted immune system reactions. For e.g. when vectors (viruses) are attacked by the immune system of the body.
• Current gene therapy mechanisms can sometimes target the wrong cells.
• The delivery viruses may mutate and become harmful.

Ethical Challenges

• For e.g. creation of GM babies using germline gene editing by a Chinese scientist attracted global criticism and fuelled debate on ethical concerns regarding applications of gene therapy technologies.
• Playing god debate

>> National Guidelines for Gene Therapy Product Development and Clinical Trials – Released by ICMR in Dec 2019: Key Highlights

• The guidelines are aimed at ensuring that gene therapies are introduced in India and clinical trials for gene therapy can be performed in an ethical, scientific and safe manner.
• They provide the general principles for developing gene therapy products (GTPs) for any human ailment and provide a framework for all areas of GTP production including pre-clinical testing, clinical administration, human clinical trials, as well as long term follow up. These must follow the established general principles of biomedical research.
• They apply to all stakeholders involved in the field of gene therapy including researchers, clinicians, oversight/regulatory committees, industry, patient support groups and any other involved in GTP development or their application in humans and their derivatives.
• The guidelines will serve as a roadmap for those in the field trying to develop gene and cell therapies and will thus contribute to accelerating the development of advanced therapeutic options
• ICMR has also proposed setting up of task force to promote gene technology research in the country.

a) CAR-T CELL THERAPY

• Why in news?
  • The CDSCO has granted market authorization for NexCAR19, India’s first indigenously developed CAR-T cell therapy, to ImmunoACT (Nov 2023)
• Background: How Cancer has been treated before CAR T-Cell Therapy:
  • Surgery (removing the cancer)
  • Radiotherapy (delivering ionizing radiation to the tumour)
  • Systematic Therapy (administering medicines that act on tumour)
    • The earliest form of systematic therapy was chemotherapy. It preferentially acts on cancer cells because of the latter’s rapid, unregulated growth and poor healing mechanisms. These drugs have modest response rate and significant side effects as they effect numerous cell types in the body.
    • The next stage in its evolution was targeted agents a.k.a. immunotherapy: The drugs bind to specific target on the cancer or in the immune cells that help the tumour grow or spread. This method often has less side effects as the impact on non-tumour cells is limited. However, it is effective only against tumours that express these targets.
• CAR-T Cell Therapy has emerged as a new development in this front.
  • It is a revolutionary therapy that modifies immune cells, specifically T-Cells, by turning them into potent cancer fighters known as CAR-T Cells.
  • How it works?
    • In CAR T-cell therapy, the patient’s blood is drawn to harvest T-cells – immune cells that play a major role in destroying tumour cells.
    • Researchers modify these cells in the laboratory so that they express specific proteins on their surface, known as chimeric antigen receptors (CAR): they have an affinity for proteins on the surface of tumour cells. This modification in the cellular structure allows CAR T-cells to effectively bind to the tumour and destroy it.
    • These modified cells are then infused back into the patient’s blood stream after conditioning them to multiply more effectively.
    • The cells are even more specific than targeted agents and directly activate the patient’s immune system against cancer, making the treatment more clinically effective. This is why they are called ‘living drugs.
  • Advantages of CAR-T Cell therapy over other Cancer fighting methods:
    • It is very accurate and only targets cancer cells.
    • It makes the treatment easier with onetime therapy (unlike several sessions of chemotherapy)
    • It can also fight non-responsive cancer patients.
    • It is designed to cure and provide lifelong benefits.

Where is it being used today? CAR T-cell therapies are approved for Leukaemias (cancers arising from the cells that produce white blood cells) and Lymphomas (arising from the lymphatic system)

It is also being used among patients with cancers that have returned after an initial successfully treatment or which haven’t responded to previous combinations of chemotherapy or immunotherapy.

• CAR T-Cell Therapy in India:
  • The first major clinical trial showing they were effective was published almost a decade ago. The first indigenously developed therapy in India was successfully performed only in 2021.
• In Oct 2023, the Central Drugs Standard Control Organization (CDSCO) granted market authorization for NexCAR19, India’s first indigenously developed CAR-T cell therapy, to ImmunoAct, a company incubated by IIT Bombay. This paves the way for commercial launch of this therapy in India.
  • It isdesigned totarget cancer cellsthat carrythe CD19 protein. This proteinacts like aflagoncancer cells, which allows CAR-T cells to recognize and attach themselves to the cancer cells and start process of elimination.
  • Who can get the NexCAR19 therapy?
    • The therapy is for people with B-Cell lymphomas who didn’t respond to standard treatments like chemotherapy, leading to relapse or reoccurrence of the cancer.
    • B-Cell leukaemia is most common among children. Are they also eligible?
      • For now, therapy’s approval is only for patients aged 15 years and above.
      • The pediatric trial phase is currently underway at the Tata Memorial Hospital, in collaboration with IIT-Bombay.
  • Significance:
    • India is one of the first developing country to have its own Car-T therapy. Even some developed nations don’t have their own CAR-T therapies and they import from USA or Europe.
    • This reduces the cost of treatment to about 1/10th of the cost abroad and has the potential of boosting medical tourism in India. It costs around Rs 3.3 crores abroad while in India it will cost somewhere between 30-40 lakh rupee.
    • Lab and animal studies have shown that NexCAR19 lead to significantly lower drug-related toxicities. For e.g., it causes minimal damage to neurons and the central nervous system, a condition known as neurotoxicity. The therapy also leads to minimal Cytokine Storm Syndrome (CRS), which is characterized by inflammation and hyperinflammation in the body due to the death of a significant number of tumour cells, as CAR-T cells are designed to target and eliminate cancer cells.

b) WHAT IS B-CELL LYMPHOMA

• B-Cell Lymphoma is a form of cancer that starts in a white B-cell called a Lymphocyte. B-Cell Lymphocytes make antibodies, the proteins in the immune system that help fight infections. They are often found in lymph nodes or other lymphoid tissues such as the spleen.
• In B-Cell Lymphoma, some lymphocytes are no longer healthy and don’t fight infections. Instead, they grow out of control, crowding out the normal cells and causing the Lymph nodes to get bigger.

c) GENE THERAPY TO TREAT SICKLE CELL ANAEMIA AND THALLASEMIA (NOV 2023) (WILL BE COVERED WITH HEALTH BOOKLET)

d) PFIZER’S HEMOPHILIA B GENE THERAPY SUCCEEDS IN LATE-STAGE STUDY (DEC 2022: SOURCE – THE HINDU)

• About Haemophilia B:
  • It is a hereditary bleeding disorder. It hampers body’s ability to make a blood-clotting protein called factor IX.
  • What happens when you bleed?
    • At the time of bleeding, a series of reactions take place in the body that helps blood clots to form. This process is called coagulation. It needs various proteins called coagulation, or clotting factors. A person has higher chances of bleeding if one or more of these factors are missing and are not functioning like they should.
    • Factor IX (nine) is one such coagulation factor. Haemophilia B is the result of the body not making enough factor IX. It is caused by an inherited X-linked recessive trait, with the defective gene located on the X chromosome.
  • Most people with haemophilia B are male. (Reason – Class discussion)
• Pfizer’s haemophilia B gene therapy succeeds in late-stage study:
  • The study showed that a single dose of the therapy was superior to the current standard of care in helping reduce the bleeding rate in patients with moderately severe to severe forms of haemophilia B.
  • Pfizer’s therapy, fidanacogene elaparovec, is designed to help patients produce factor IX themselves after a one-time treatment, as opposed to current treatments, which focus on regular infusions of the protein.
• Pfizer is also testing other experimental gene therapies in late-stage trials as potential treatments for the bleeding disorder haemophilia A and muscular disorder Duchenne muscular dystrophy.

e) NOTE: HAEMOPHILIA A

• It is also called factor VIII(8) deficiency or classic haemophilia. It is a genetic disorder caused by missing or defective factor VIII (FVIII), a clotting protein.

f) DUCHENNE MUSCULAR DYSTROPHY

• About muscular dystrophy:
  • It is a group of diseases that cause progressive weakness and loss of muscle mass. In muscular dystrophy, abnormal genes (mutations) interfere with the production of proteins needed to form healthy muscle.
  • There are many kinds of muscular dystrophy. The Symptoms of most common variety begin in Childhood, mostly in boys. Other types don’t surface until adulthood.
  • Sign: The main sign of muscular dystrophy is progressive muscle weakness. Specific signs and symptoms begin at different ages and in different muscle groups, depending on the type of muscular dystrophy.
• About Duchenne muscular dystrophy:
  • Most common type of muscular dystrophy.
  • Although girls can be carriers and mildly affected, it’s much more common in boys.
  • Signs and symptoms which typically appear in Childhood are:
    • Frequent falls
    • Difficulty rising from a lying or sitting position
    • Trouble running and jumping
    • Walking on the toes
    • Large calf muscle
    • Delayed growth
    • Learning disabilities.
• Other types of muscular dystrophy include: Becker Muscular Dystrophy

g) MOLECULAR DIAGNOSIS

• For treatment of any disease, early diagnosis and understanding its pathophysiology is very important. Using conventional methods of diagnosis (serum and urine analysis, etc.) early detection is not possible.
• Recombinant DNA technology, Polymerase Chain Reaction (PCR) and Enzyme linked Immuno-Sorbent Assay (ELISA) are some of the techniques that serve the purpose of early detection.
  • PCR is a technique used in molecular biology to amplify a single copy or a few copies of a piece of DNA across orders of magnitude, generating thousands to millions of copies of a particular DNA sequence.
    • It is now routinely used to detect HIV in suspected AIDS patients. It is being used to detect mutations of genes in suspected cancer patients too.
  • ELISA is based on the principle of antigen-antibody interaction. Infection by pathogen can be detected by the presence of antigens (proteins, glycoproteins etc.) or by detecting the antibodies synthesized against the pathogens.
• E.g. Tests During COVID-19
  • RT-PCR Test
    • The test detects the presence of viral RNA in human samples.
    • In this test first the viral RNA is converted into DNA (reverse transcription)
    • PCR is a process where a few copies of DNA are amplified to produce millions of copies.
    • This is done with the help of enzymes, primers, and probes.
  • Rapid Anti-Body Test
    • A rapid test is conducted to determine if there has been any kind of recent viral infection in a person’s body. When a pathogen enters a human body, specific anti-bodies are released as a response to the virus. A rapid test can detect the presence of such anti-bodies in blood, serum or plasma samples question.
    • This is a simple test and can give results in 10-30 minutes.
    • It should be noted that it is not a confirmatory test for COVID-19. It is only a preliminary screening for diagnosis of coronavirus infection.
    • Further, a negative test doesn’t rule out COVID-19 infection. A rapid test comes positive after 7-10 days of viral infection and remains positive for several weeks after that.

h) DISEASE CONTROL THROUGH GENETICALLY MODIFIED ORGANISMS

• By introducing sterile mosquitoes (genetically formed). (concept – not done yet)
• Synthetic vector genome which is incapable of hosting the parasite and/or virus.

i) PERSONAL GENOMICS

• It is the branch of genomics concerned with sequencing and analysis of the genome of an individual. The genotyping stage employs different techniques, including single-nucleotide polymorphism (SNP) analysis chips (typically 0.02% of the genome), or partial or full genome sequencing.
• Uses
  • Once the genotypes are known, the individual’s genotype can be compared with the published literature to determine likelihood of trait expression and disease risk.
  • Personalized medicines
    • It is a medical method that targets treatment structures and medicinal decisions based on patient’s predicted response or risk of disease.
    • Various subcategories of personalized medicines
      • Predictive Medicines
      • Precision Medicines
      • Stratified Medicines
• It predicts the right kind of treatment
  • Efficacy of toxicity of chemotherapy, or radiotherapy etc.

4) TRANSGENIC ANIMALS

• Animals that have their DNA manipulated to possess and express an extra (foreign) gene are known as transgenic animals.
  • Transgenic rats, rabbits, pigs, sheep, cows and fish have been produced, although over 95% of all existing transgenic animals are mice.
  • Why so much medical research on mice, rat?
    • Genetic, biological and behaviour characteristics closely resemble that of humans and many symptoms of human conditions can be replicated in mice and rats.
    • We share between 95% of the same genes, and our immune system are even more compatible.
    • Therefore, the result of mouse experiment often correlates to human biology
    • Further, mice can be genetically manipulated to mimic virtually any human disease or condition.
  • Convenience
    • Rodents are small, easily housed and maintained, and adapt well to the new surroundings.
  • Reproduce quickly and short lifespan: Reproduce quickly and have short life span of 2-3 years – so several generations of mice can be observed in sort span of time.
  • Relatively Inexpensive
    • Can be brought in large quantities from commercial producers
  • Mild tempered and docile
    • Rodents are also generally mild tempered and docile, making them easy for researchers to handle.
• How transgenic animals are helpful?
  • Normal physiology and development
    • Experimenting on how alteration of genes would affect humans.
  • Study of disease
    • Many transgenic animals are designed to increase our understanding of how genes contribute to the development of disease.
  • Biological Products
    • Some medicines might require some biological products which are often expensive to produce.
      • Transgenic animals that produce useful biological products can be created by the introduction of portion of DNA (or genes) which code for a particular product.
        • E.g. : Human protein (α-1-antitrypsyn) used to treat emphysema.
        • In 1997, the first transgenic cow – Rosie, produced human protein-enriched milk (2.4 grams per liter).
          • The milk contained the human alpha-lactalbumin and was nutritionally a more balanced product for human babies than natural cow milk.
  • Vaccine Safety
    • Transgenic mice are being developed for use in testing of safety of vaccines before they are used on humans.
    • Transgenic mice are being used to test the safety of the polio vaccine.
  • Chemical safety testing
    • This is known as toxicity safety testing.
    • The procedure is same as used for testing toxicity of drugs.

5) BIOTECHNOLOGY AND ENVIRONMENT

A) GM ALGAE, CROPS ETC. CAN PROVIDE MORE BIOMASS FOR BIOFUEL.

B) BIODIVERSITY CONSERVATION

a. E.g. -> De-extinction of species; Colossal is a new bioscience and genetics company, with the idea of bringing many extinct species back to life. Scientists at Harvard University in the USA would insert the Giant Woolly mammoth’s (extinct 4,000 years ago) genes responsible for tiny ears, subcutaneous fat and hair length and color into living elephant skin cells. Once they are successful in bringing these hybrids back to life, Colossal will proceed with the ultimate goal of reviving the ancient extinct animals by producing more such hybrids.

Criticism: Immoral; revival of these species may threaten the existing ecosystem and disturb the food chain which has evolved over the years; Rather than focusing on revival of long extinct species, biotechnology should focus on protecting the existing ones.

C) TO DETECT INVASIVE SPECIES:

• Environmental DNA based assay to detect invasive catfish in waterbodies (Nov 2022 – Source: DTE)
  • Conventional methods to detect invasive species like using nets, traps, and visual observations, are cumbersome,the researchers from CCMBnow havedeveloped EnvironmentalDNA(e-DNA) based molecular methods to provide a time and cost-effective alternative.
  • eDNA is defined as “genetic material obtained directly from environmental samples (soil, sediments, water etc.) without any obvious signs of the biological source material. It is an efficient, non-invasive and easy-to-standardize sampling approach. It can be obtained from ancient as well as modern environment. With scientific advancements in DNA sequencing technologies, the technique is increasingly being used for biodiversity monitoring.
  • CSIR-CCMB has designed a molecular assay utilizing eDNA to specifically detect this invasive catfish in Indian ecosystem, which is affordable and quick, and will be very useful tool in conservation management. They use a reliable eDNA-based quantitative PCR assay to detect the African Sharptooth Catfish from water samples in the aquatic system.

6) GM INSECTS

• A genetically modified (GM) insect refers to insects whose DNA has been engineered through various genetic engineering tools like CRISPR CAS9.
• Various GE insects are available globally today. The development and application of GE insects offers applications in various fields:
  • Improving Human Health:
    • Vector Management in human and livestock health: GE mosquitoes for e.g. can be designed to carry genes that limit their ability to transmit diseases such as dengue, malaria etc.
    • Reduction in use of chemicals -> Maintenance and improvement of both human health and environmental health.
  • Food Security:
    • Management of crop insect pests: Insects can be genetically engineered to carry traits that reduce the population of agricultural pests.
      • For e.g. introducing sterile males can help control pest population.
    • Increased food production: Protein production for healthcare purposes; honey production etc.
      • Engineering honeybees to make better-quality and/or quantities of honey can contribute to reduced imports and may facilitate exports.
    • Improvement in beneficial insects like pollinators, predators, parasitoids etc.
  • Economic Application:
    • Other than improved agri production, improvements in productive insects (e.g. silkworm, lac insect) etc can promote economic growth.
      • E.g. GE silkworms can produce finer and/or cheaper silk, affecting prices and boosting sales.
  • Fighting pollution and ensuring environmental sustainability:
    • Reduction in use of chemical will contribute to reduced pollution and environmental sustainability. Similarly, improved pollinators can contribute to biodiversity production.
    • Some GE insects can be used as bio-indicators to monitor pollution or detect some specific substance in environment.
• Some Concerns:
  • Ecological Risk: Once introduced in the environment, it’s very difficult to contain these insects. And if some future problem emerges, it would be difficult to control.
  • Unforeseen health implications when these GM insects interact with humans.
  • Bioweapons: GE insects may be used to produce bioweapons.
  • Regulatory challenges: Government guidelines like Guidelines for Genetically Engineered insects; National Guidelines for Gene Therapy Product Development and Clinical Trials’ have similar ambiguity.
  • Ethical concerns: GE insects raise a question – “If human being should act as God” and make changes in the living organisms around it.

A) GUIDELINES FOR GENETICALLY ENGINEERED (GE) INSECTS: RELEASED BY DBT IN APRIL 2023

• The guidelines provide procedural roadmaps for those interested in creating GE insects.
  • It intends to help Indian researchers navigate regulatory requirements.
  • The guidelines are harmonized to guidance from WHO on GE mosquitoes.
• But experts have identified some issues with the guidelines:

a) Uncertainty of Purpose: The guidelines don’t specify the purpose for which GE insects may be approved in Indi It only provides regulatory procedures for R&D on insects with some beneficial applications.

b) Uncertainty for Researchers: The guidelines are applicable only to research and not to confined trials or deployment.

» Government authorities will also have to closely follow the deployment of these insects. Once deployed, the GE insects can’t be recalled, and unlike GM foods, they are not amenable to individual consumer choice.

d) Uncertainty of Ambit: The guidelines offer SOPs for GE mosquitoes, crop pests, and beneficial insects – but what ‘beneficial’ means, in the context is GE insect is not clear.