Biotechnology Study Notes
Definition of Biotechnology
Biotechnology deals with the industrial-scale production of biopharmaceuticals and biologicals using genetically modified microbes, fungi, plants, and animals.
Applications of Biotechnology
Applications include therapeutics, diagnostics, genetically modified crops, processed food, bioremediation, waste treatment, and energy production.
Key Research Areas in Biotechnology
Three critical research areas are: providing improved catalysts (organisms/enzymes), creating optimal conditions for catalysts, and developing downstream processing technologies for purification.
Options for Increasing Food Production
Three options are agro-chemical based agriculture, organic agriculture, and genetically engineered crop-based agriculture.
Limitations of Green Revolution
While the Green Revolution tripled food supply, it wasn't enough for the growing population. Increased yields relied on improved varieties, management, and agrochemicals, which are expensive for developing world farmers.
Introduction to Tissue Culture
Tissue culture, developed in the 1950s, allows whole plants to be regenerated from explants (plant parts) grown in sterile nutrient media.
Totipotency
Totipotency is the capacity to generate a whole plant from any cell or explant.
Nutrient Medium for Tissue Culture
The nutrient medium must provide a carbon source (like sucrose), inorganic salts, vitamins, amino acids, and growth regulators (auxins, cytokinins).
Micro-propagation
Micro-propagation is the method of producing thousands of plants through tissue culture in a short duration.
Somaclones
Somaclones are plants produced through tissue culture that are genetically identical to the original parent plant.
Virus-Free Plants via Meristem Culture
Meristem (apical and axillary) tissue is often virus-free, allowing for the recovery of healthy plants from diseased ones through in vitro culture.
Somatic Hybridization
Somatic hybridization involves fusing isolated protoplasts (plant cells without cell walls) from different varieties to create new hybrid plants with combined characteristics.
Genetically Modified Organisms (GMOs)
GMOs are organisms whose genes have been altered by manipulation. GM plants offer benefits like tolerance to abiotic stresses, reduced pesticide reliance, and enhanced nutritional value.
Bt Toxin and Pest Resistance
Bt toxin, produced by Bacillus thuringiensis, is used to create pest-resistant crops like Bt cotton. The toxin gene is cloned and expressed in plants, providing insect resistance.
Mechanism of Bt Toxin Action
Bt toxin exists as an inactive protoxin. In the insect's alkaline gut, it's activated, binds to midgut cells, forms pores, causing swelling, lysis, and insect death.
RNA Interference (RNAi) for Nematode Control
RNAi is a defense mechanism that silences specific mRNA. In plants, nematode-specific genes introduced via Agrobacterium vectors produce dsRNA, initiating RNAi and protecting the plant from nematodes.
Genetically Engineered Insulin
Recombinant DNA technology allows for the mass production of human insulin. Chains A and B are produced separately in E. coli and then combined to form mature human insulin.
Challenges in Insulin Production
A key challenge was assembling the insulin chains into a mature, functional form with correct disulfide bonds.
Gene Therapy
Gene therapy aims to correct genetic defects by inserting normal genes into a person's cells or tissues to compensate for non-functional genes.
First Gene Therapy Case
The first clinical gene therapy in 1990 treated a 4-year-old girl with adenosine deaminase (ADA) deficiency, using a retroviral vector to introduce a functional ADA cDNA into her lymphocytes.
Molecular Diagnosis Techniques
Techniques like PCR and ELISA enable early diagnosis of diseases by detecting pathogens or genetic mutations, often before symptoms appear.
Polymerase Chain Reaction (PCR)
PCR amplifies nucleic acids, allowing the detection of very low concentrations of pathogens or mutations, routinely used for HIV and genetic disorder detection.
Hybridization and Autoradiography
A radioactive-tagged DNA/RNA probe hybridizes to its complementary DNA. Autoradiography detects the presence or absence of the target gene, useful for identifying mutations.
Enzyme Linked Immuno-sorbent Assay (ELISA)
ELISA is based on antigen-antibody interactions and is used to detect infections by identifying pathogen antigens or antibodies produced against them.
Transgenic Animals
Transgenic animals have manipulated DNA to possess and express foreign genes. They are produced for studying physiology, disease models, producing biological products, and testing vaccine/chemical safety.
Studying Normal Physiology with Transgenic Animals
Transgenic animals help study gene regulation and their effects on normal body functions and development, such as investigating growth factors.
Transgenic Animals as Disease Models
Many transgenic animals are created as models for human diseases like cancer and Alzheimer's to facilitate research into new treatments.
Biological Products from Transgenic Animals
Transgenic animals can produce valuable biological products for treating human diseases, such as human protein-enriched milk from transgenic cows.
Transgenic Animals for Vaccine Safety Testing
Transgenic mice are being developed to test the safety of vaccines, potentially replacing the use of monkeys.
Chemical Safety Testing with Transgenic Animals
Transgenic animals engineered to be more sensitive to toxic substances are used for faster toxicity and safety testing of chemicals.
Ethical Considerations in Biotechnology
Manipulation of living organisms requires regulation and ethical evaluation of activities that may help or harm them.
Unpredictable Results of Genetic Modification
Introducing genetically modified organisms into the ecosystem can lead to unpredictable and potentially harmful results.
Role of GEAC in India
The Genetic Engineering Approval Committee (GEAC) in India makes decisions regarding the validity of GM research and the safety of introducing GM-organisms for public services.
Patent Issues and Biopiracy
Patents granted for products and technologies using genetic materials and traditional knowledge of farmers and indigenous people raise ethical concerns and can lead to biopiracy.
Biopiracy Definition
Biopiracy is the unauthorized use of bio-resources and traditional knowledge by multinational companies without proper authorization or compensation.
Indian Patents Bill Amendment
The second amendment of the Indian Patents Bill addresses issues like unauthorized exploitation of bio-resources and traditional knowledge, including patent terms and emergency provisions.