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Cloning. Production of identical copies of molecules, genes, cells, or entire organisms Simple way to make a clone of a plant – cutting from a plant, place in water to grow roots then placed in pot and then it will produce a plant genetically identical to original. Cloning (cont’d).
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Cloning • Production of identical copies of molecules, genes, cells, or entire organisms • Simple way to make a clone of a plant – cutting from a plant, place in water to grow roots then placed in pot and then it will produce a plant genetically identical to original
Biotechnology and Human Body • 3000 known diseases linked to genes and scientists can diagnose more than 200 of them • Genetic disease – caused by a defect in person’s DNA • May result from mutation or due to missing or extra gene or chromosome • May lead to physical or physiological disorders • Genetic screening – looking at a magnified image of person’s chromosomes • Picture of cell’s chromosome – karyotype • Gene therapy – allows scientists to replace defective genes with healthy ones • One method – uses an altered virus • Virus normally attacks cells by attaching to cell’s outer membrane and then pushing its own DNA into cell – viral DNA uses the host cell to make copies of itself • Altered virus – splice a healthy gene into viral DNA and let virus transfer the gene into patient’s cells
Gene therapy using somatic cells can help inherited diseases • Avoid passing on disease to offspring, defective genes need to be located and altered in patient’s sex cells • All genes found in complete set of chromosomes – genome • Mapping entire human genome – provide ideal tool for diagnosing genetic disorders • Human Genome Project – 1990 in USA, locating approximately 100 000 genes that are found in one set of 23 human chromosomes • Work involved many nations, use DNA probes (short strands of labelled DNA) that attach to specific genes • This helped find gene responsible for cystic fibrosis – disease that affects pancreas and lungs
Making Human Proteins • Produce the product of the gene – diabetic individuals cannot produce own insulin • 1978 – human gene for making insulin was transferred into bacteria – insulin manufactured by bacteria has the advantage of being human insulin which decreases the possibility of an allergic reaction (unlike insulin from cows or pigs) • Hormone can be produced in bacteria in large quantities and relatively inexpensive • Bacteria also used to produce human growth hormone and interferon (protein for immune system) • Animals and bacteria – can be given human genes – adding to fertilized eggs or parents – offspring grow up with human gene • Advantage of using mammals is that proteins can be collected in mammal’s milk – do not have to be killed
Biotechnology in Agriculture • New crops – always trying to improve crop production – cross-pollination of 2 strains of crop by hand in order to crate a new combined variety = hybrid • Cropbreeders can now select a specific genetic trait from one species and move it into the genetic code of a crop plant • Allows breeders to choose the particular genetic characteristics they want • Gives breeders the alternative of using genes from unrelated species (including animals or micro-organisms) as well as plants • Wheat variety – may contain a gene that allows it to resist a specific pest – transferred to different species of plants • 1990’s – 86% of all genetically engineered crops in Canada were altered to be tolerant of herbicides – used to kill unwanted plants, weeds • Herbicides can kill crops – given a gene to function in presence of herbicide = crops can be sprayed with concentration, spray less often (cost as well as environment)
Biotechnology in Agriculture (cont’d) • Canola – Canadian and oil • Ancestor is a plant called rapeseed – used in Asia and Europe in lamps, for cooking, in foods • Today – seeds contain the highly desirable oil used in shortening, salad oil, cooking spray, printing ink, hydraulic fluids, suntan lotion • Rapeseed grown in Canada since 1936 – high demand during WWII as one or most effective lubricants for metal engine parts • Edible rapeseed oil extracts were first put to use on market 1956-57 • Distinctive taste and disagreeable greenish color due to presence of chlorophyll, high concentration of erucic acid (suspected to cause cancer if ingested large amounts) • Plant breeders – improve quality of rapeseed in 1968 – used selective breeding to develop low erucic acid • 1974 – low erucic acid and low levels of glucosinolates • Today 75% of Canola crops in Alberta, Manitoba and Saskatchwan are herbicide tolerant
Canola (cont’d) • Most favourable overall combination of saturated and unsaturated fats for healthy diet • Monoculture – situation where large parts of a country are planted with a single variety of a crop or limited number of varieties – prone to large-scale destruction by single pest or disease
New Animals • Aquaculture – increasing important method of fish production due to decline of natural fish stocks in oceans and lakes • Added genes for disease resistance to some varieties of fish and growth hormone genes have been introduced to fish eggs to increase size and growth rate of fish • Antifreeze gene into Atlantic salmon – protein that prevents the fishes blood from freezing • Hormones have been introduced to increase production of farm animal products • Bovine Growth Hormone (BGH) – controls calf growth and milk production – cows injected with this hormone can produce more milk • Must be injected regularly into cows to see benefits • Concerns – using the hormone might increase chances of some types of infection in cows • Increase costs of antibiotics, veterinarians, nutritionists are more cost-effective on large-scale farm operations with many cows producing increased revenue • In 1999 – federal government did not approve use of BGH for milk production in Canada
Biotechnology in Environment • How to clean up toxic wastes left over – carelessness or released into environment by accident or negligence • Canada – might have to spend billions of dollars for environmental clean-up • Across Canada – over 1000 sites are contaminated with hazardous materials
Bioremediation • 1980’s – look for ways to use micro-organisms to break down the complex compounds in toxic wastes = bioremediation • Decomposers (bacteria, fungi, micro-organisms) use dead plant and animals as food • Different species of these – break down and decompose almost anything including chemicals that are toxic to humans • Trick is to find the right ones for the substances • Micro-organisms have been found to break down toxic compounds such as methylene chloride • Most often requires a group of organisms each responsible for a certain step – called consortia
Bioremediation (cont’d) • Injecting micro-organisms into ground along with nutrients that will help them grow • Others – only oxygen or nutrients are needed to nourish micro-organisms that are already in soil • Cost effective (only 1/5 the cost of previous methods) • Treating contamination without causing major disturbance to area and minimal intervention
Oil Spills and Bioremediation • 1989 – Alaska – oil tanker released 42 million liters of crude oil – killed thousands of animals • 33 000 sea birds, 146 bald eagles, 980 sea otters had been found dead • Oil covered 1600km of shoreline • To remove oil – used steam, towels, oil-eating bacteria were spread on shoreline with nitrogen and phosphorus fertilizers to aid in growth • Between 1976 and 1987 – over 300 significant oil spills occurred off Canada’s east and west coasts • 1988 – Washington state – spilled 875t of oil which drifted up to Vancouver Island – killed 46 000 shorebirds
Heavy Metal Biotechnology • Mercury, copper, zinc, lead – result in damage to nervous, circulatory, digestive and reproductive systems of humans • Released into environment by industrial and mining activities, urban storm run-off, leaching of rocks and soil by acid rain • Micro-organisms may prove useful in gathering heavy metal pollutants • Bacteria, fungi, algae – use metals in soil or rocks to produce energy • Cabbage, mustards, radishes – can concentrate heavy metals in their roots • These plants can be genetically altered to take up specific metals from the soil • Plants do not remove them, they just concentrate the metals • Plants must be harvested and then disposed safely to remove pollutants
Species Preservation • Overfishing, pollution, global climate change – reduce diversity of marine life throughout the world • Oceans – organisms have unique biochemical characteristics that provide opportunities for solving a variety of medical problems • Bacterium that lives with sponges and sea squirts – chemicals that kill viruses • Compound found in deep-sea bacterium – used to inhibit HIV virus • Many sponges and corals – make chemicals that reduce inflammation and pain of acute asthma, arthritis and injuries • Other marine organisms – antibiotics and antibodies
Species Preservation (cont’d) • Biotechnology can also be used to preserve some endangered species • Bred in captivity to increase numbers • Inbreeding – mating 2 closely related individuals may increase chance of genetic diseases, offspring less genetically variable from those mating of non-related parents • Solution – DNA fingerprinting – identify individuals but also determine how closely related they are • Pair unrelated individuals to produce offspring – selective breeding to maintain genetic variation • Mating unsuccessful – discover why female cannot become pregnant or analyze semen of partner • Goal of such inbreeding – return endangered species to their natural habitats – enough suitable habitat remaining in wild to support these plants and animals
Where do we go from here? • Food you eat, treatment of disease, well-being of your children, environment in which you live will be determined by what happens in biotechnology • Decisions made will depend on clear understanding of science and technology involved as well as people’s beliefs