Producing drugs using genetically modified organisms

Genetic Modification Techniques

1. Selective Breeding2. Genetic Engineering aka. Recombinant DNA

technology

Genetic Engineering Process

1. Extraction of desired gene from host organism

2. Gene inserted into vector for transportation into new organism

Gene Extraction Process

1. Extracting gene from host cell chromosomes2. Extracting mRNA from host cell

Production of Gene From mRNA (human insulin)

1. mRNA coding for insulin production removed from pancreas

2. Complementary DNA (cDNA) strand synthesised (reverse transcriptase)

3. Second DNA strand synthesised on cDNA base (DNA polymerase)

GM Microorganisms: Treating Diabetes Using Modified E-Coli

1. Human genes for insulin transferred to mutant form of E-Coli

2. Modified E-Coli cultured in fermenter3. E-Coli secretes insulin which is extracted and

used in treating diabetes

GM animals

• Manipulating genes in eukaryotes is more difficult than in prokaryotes due to:1. Plasmids cannot be used to introduce new genes2. Eukaryotes are diploid3. Transcription of DNA to mRNA more complex4. Gene expression process less understood

Introducing genes into Eukaryotic Cells

1. Injection2. Bombardment3. Electroporation

Treating emphysema using modified sheep

• Emphysema is the break down of the inner walls of the alveoli

• Caused by lack of AAT protein• Sheep modified with human AAT genes so that

they produce AAT rich milk

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GM Plants: Vaccines

• Antigen from animal pathogen added to plant virus surface

• Plant virus used as vaccine, triggers creation of antibodies against antigen

• Less associated safety risk as chosen plant virus cannot harm animals

Environmental and Ethical Issues of Genetic Engineering