Recombinant DNA - Definitions Gene: section of DNA which codes for a protein Recombinant DNA (rDNA): - DNA from one species (e.g. gene coding for protein Insulin) inserted into DNA of a second species (e.g. Bacteria) - Second species can then go on to produce proteins of first species - when it reproduces, it will copy other species' DNA and pass it onto its offspring - Gene has been "cloned" - Can also make many copies of DNA being studied (“amplification”)
Recombinant DNA - Uses Cloning Genes: - viruses/bacteria can be used to make copies of the gene(s) of another species Producing Biotechnology Products: - genetically engineered prokaryotic/eukaryotic cells can be used to mass produce once rare medicinal proteins, hormones, vaccines to prevent disease (e.g. hepatitis B) - produce large amounts of proteins that are very difficult to get otherwise or usually present in small quantities from ntural sources - e.g. human growth hormone - once took 50 pituitary glands from cadavers for a single dose - can now be made in mass quantities, much less expensively - e.g. insulin used to come from the pancreatic glands of cows, pigs - was expensive, much less pure than cloned human DNA available today
Recombinant DNA - Uses Transgenic Organisms: Transgenic Bacteria: - alter DNA of bacteria, plants, farm animals to make them more valuable, less susceptible to disease Transgenic Bacteria: - Protect/Enhance Plants: protect plants from frost, provide more nitrogen to roots, produce insecticides to kill insects - Garbage Disposal: engineered to eat toxic waste, clean up oils spills, filter air, remove sulfur from coal (bioremediation) - Produce Chemicals: produce phenylalanine, used in production of artificial sweeteners - Process Minerals: extract greater amounts of metals (e.g. U, Cu, Ag) from low-quality ores
Recombinant DNA - Uses Transgenic Plants: - used in agriculture: bacterium Agrobacterium, which naturally infects many plants, artificial vectors called protoplasts - contain new genes that help resist insects, viruses, herbicides (e.g. “Roundup” resistant wheat), temperature extremes, drought, salty soils, spoiling, bruising Transgenic animals: - bigger animals can be produced more cheaply - inject DNA that codes for the uptake of bovine growth hormone (bGH) into eggs of fish, cows (25% greater milk production), pigs, rabbits, sheep Gene Farming: - use of transgenic farm animals to produce pharmaceutical drugs like human lactoferrin (absence of gene for lactoferrin in humans causes reoccurring bacterial infections of the intestine)
Recombinant DNA - Uses Gene Therapy: - replace defective genes in a living organism (humans) with healthy genes, used to treat genetic disorders/diseases - Ex Vivo: cells removed from patient, treated, returned - retroviruses used to introduce nucleic acid into cells to be treated - e.g. treating SCID (severe combined immunodeficiency syndrome) sufferers lack an enzyme needed for certain white blood cells - insert correct gene into patient’s WBC or stem cell, reinsert - In Vivo: introduce genes right into the bodies of patients - e.g. treat hemophilia with regular injections of cells that have normal genes for normal clotting-factors
Recombinant DNA - Methods Vector: - something that can get DNA from one species into other species' DNA - e.g. plasmid, circular piece of DNA found in some bacteria - human gene, e.g. gene for insulin, inserted into plasmid, plasmid taken up by bacteria - bacteria reproduces plasmid along with its own DNA when it reproduces, translates human gene, producing human protein
Recombinant DNA - Methods