BIO2015: Lecture 1

Genetic engineering/recombinant DNA technology:

• Isolate & characterise genes
• produce and characterise genes
• alter genetic makeup of organism- new genes, loss of existing genes e.g. through RNAi

Genetic engineering history:

• First discovered in mid 1940s that DNA can be transferred between different organisms
• particularly between different bacteria- lateral transfer
• pioneered by Cohen and Boyer 1972-1974 in bacterial systems
• Southern hybridization developed in 1975 (Ed Southern)
• DNA sequencing: 1977-1980
• Transgenic animals made in 1980 (mouse)
• genetically modified plants were made in 1983 (antibiotic resistant tobacco)
• plant genetic engineering much further advanced than it is for animals- because of moral considerations
• polymerase chain reaction (PCR) made 1985
• site-directed mutagenesis made 1985
• first transgenic product on market Flavr Savr tomato approved for marketing in USA (1994)- only 11 years after first genetically produced plant
• mad cow disease meant that people lost faith in government food sciencists
• Bt corn, cotton potatoe, herbicide tolerant soybean commercialised 1995
• first transgenic animal declared safe to eat by FDA in 2012, 17 years after registration

Traditional Breeding

• to encourage trait- cross 2 organisms with that trait
• with genetic engineering you can transfer gene from one organism to another or use completely synthetic gene

gene knockouts- best way to figure out what gene does- remove it and see what happens

Practical applications of genetic engineering

• Production of industrially important proteins
• change properties of proteins
• modification of phenotype of whole organism
• diagnosis
• primary applications in agriculture
• primary applications in medicine
• other include chemical, paper, and detergent industries
• protein production
• pharmaceutical proteins:
• constant supply and safe
• growth hormone, insulin, factor VIII & IX, antitrypsin
• insulin produced from recombinants was problematic because people who were previously on bovine insulin had to adjust
• microbial proteins:
• microbes grow poorly but produce valuable enzymes-
• hyperthermophiles
• anaerobes
• archaebacteria
• genetic engineering makes these proteins available to industry

Plant biotech pipeline:

• 1st generation plants- i.e. those which were known to be insect resistant, herbicide tolerant etc.. conferred agronomic traits- seen by public as for advantage of growers rather than consumers- a lot of scepticism- although there were large benefits to environment
• 2nd generation- i.e. enhanced nutritional foods- seen as beneficial to consumers
• 3rd generation- using plants as biofactors- e.g. production of pharmaceuticals- usually use microorganisms but can use plants- one plant favoured is maize- concern that there could be gene flow into maize for animal consumption- also used for renewable industrial feedstock or biofuels

Role of biotech. in agriculture…