biotechnology and its applications

Biotechnology (modern context) ; Industrial scale production of biopharmaceuticals and biologicals using genetically modified microbes, fungi, plants and animals

Applications of biotechnology ; Therapeutics, diagnostics, GM crops, processed food, bioremediation, waste treatment, energy production

Three critical research areas of biotechnology ; Improved catalyst, optimal engineering conditions, downstream processing

Best catalyst in biotechnology ; Improved organism (usually microbe) or pure enzyme

Downstream processing ; Purification of protein/organic compound

Three approaches to increase food production ; Agrochemical agriculture, organic agriculture, genetically engineered crop-based agriculture

Green Revolution ; Tripled food supply but insufficient for growing population

Major reason for increased yield during Green Revolution ; Agrochemicals and improved management practices

Genetically Modified Organisms (GMOs) ; Plants, bacteria, fungi or animals whose genes have been altered

Abiotic stress tolerance in GM crops ; Cold, drought, salt, heat

GM crops reduce ; Reliance on chemical pesticides

Golden rice ; Vitamin A enriched rice

Bt toxin ; Produced by Bacillus thuringiensis

Bt crops ; Express Bt toxin gene to provide insect resistance

Examples of Bt crops ; Cotton, corn, rice, tomato, potato, soyabean

Bt toxin in bacteria ; Exists as inactive protoxin

Activation of Bt toxin ; Occurs in alkaline pH of insect gut

Action of activated Bt toxin ; Binds to midgut epithelial cells and creates pores causing lysis

Cry genes ; Code for Bt toxin proteins

cryIAc and cryIIAb ; Control cotton bollworms

cryIAb ; Controls corn borer

Meloidegyne incognitia ; Nematode infecting tobacco roots

RNA interference (RNAi) ; Cellular defense mechanism involving silencing of specific mRNA

Mechanism of RNAi ; Complementary dsRNA binds and prevents translation of mRNA

Sense and antisense RNA together form ; Double-stranded RNA (dsRNA)

Result of RNAi in nematode control ; Parasite cannot survive in transgenic host

Recombinant therapeutics ; Do not induce unwanted immunological responses

Genetically engineered insulin ; Produced using rDNA technology in bacteria

Insulin structure ; Two polypeptide chains A and B linked by disulfide bonds

Proinsulin ; Contains extra C-peptide

C-peptide ; Removed during maturation of insulin

First company to produce human insulin using rDNA (1983) ; Eli Lilly

Gene therapy ; Correction of gene defect by introducing normal gene

First clinical gene therapy (1990) ; 4-year-old girl with ADA deficiency

ADA deficiency ; Caused by deletion of gene for adenosine deaminase

Vector used in ADA gene therapy ; Retroviral vector

Limitation of lymphocyte gene therapy ; Requires periodic infusion

Permanent cure possibility in ADA ; Gene introduced at early embryonic stage

PCR ; Detects very low concentration of pathogen DNA

ELISA ; Based on antigen-antibody interaction

Molecular probe ; Single-stranded DNA/RNA tagged with radioactive molecule

Autoradiography ; Used to detect hybridisation of probe

Transgenic animals ; Animals with manipulated DNA expressing foreign gene

Percentage of transgenic animals that are mice ; Over 95%

Use of transgenic animals ; Study physiology, disease models, biological products, vaccine safety, toxicity testing

First transgenic cow (1997) ; Rosie

Rosie produced ; Human protein-enriched milk (2.4 g/L)

Human protein in Rosie’s milk ; Alpha-lactalbumin

Gene therapy definition (NCERT summary line) ; Insertion of genes into individual’s cells and tissues to treat disease

GEAC ; Genetic Engineering Approval Committee