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Genetic Engineering Chapter 15
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What is Biotechnology?
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Until recently, scientists could not modify the genetic code of living things.
They were limited by the variation that exists in nature. Today scientists can go right to the genetic code and re-write an organisms DNA, transfer genes at will from one organism to another, and design new living things to meet specific needs.
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Biotechnology Biotechnology is the commercial application of biological products. It is a wide ranging scientific field which includes the manipulation of living organisms that results in new products or processes by that cell.
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How Old Is Biotechnology ?
10,000 BC Domesticating Crops 6,000 BC Brewing Beer Domesticating Animals 8,000-9,000 BC 1880’s Production of Vaccines 1940’s Production of Antibiotics 1980’s Use of genetically modified organisms
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Modern Biotechnology Fields of Study: Molecular Biology - microbiology
- biochemistry - cell biology Molecular Genetics Genetic Engineering: Moving a gene from one organism to another - chemical engineering - biomanufacturing
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15.1 Selective Breeding
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Selective Breeding Humans use selective breeding to pass desired traits on to the next generation of organisms. Hybridization – The crossing of dissimilar individuals to bring together the best of both organisms. Hybrids Inbreeding is the continued breeding of individuals with similar characteristics. Pure breeds
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Inbreeding The goal is to maintain the desired characteristics of a line of organisms. There are higher occurrences of genetic mutations in inbred species. Because most members of a species are genetically similar, there is a chance that a cross between two individuals will bring together two recessive alleles for a genetic defect.
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Increasing Variations
Breeders can increase the genetic variation in a population by inducing mutations. You can increase the mutation rate using radiation and chemicals. Most mutations can be harmful but sometimes they can bring desirable characteristics.
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Bacterial Mutations Scientists increase the rate of mutations in bacteria using radiation or chemicals in an attempt to breed helpful bacteria. Ex. Oil digesting bacteria
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Polyploid Plants Drugs prevent separation of chromosomes during meiosis resulting in plants with double or triple the chromosome number called polyploids. These plants are desirable because they are larger and stronger. Ex. Oat, peanuts, bananas
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15.2 Recombinant DNA
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Manipulating DNA Until recently, scientists could not modify the genetic code of living things. They were limited by the variation that exists in nature. Today, scientists can manipulate the DNA of organisms. Scientists can go right to the genetic code and re-write an organisms DNA, transfer genes at will from one organism to another, and design new living things to meet specific needs.
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Steps to Manipulating DNA
Cut the DNA. Find the desired gene. Copy the gene sequence. Manipulated DNA sequence is ready for application.
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Cutting DNA DNA is large and must be cut up into smaller pieces that can easily be read and utilized. Restriction enzymes are used to cut DNA into more manageable restriction fragments.
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Cutting DNA
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Find the Desired Gene Scientists use the Southern Blot method to find a specific gene among millions of DNA restriction fragments. Once a gene is found it is added to the genome database.
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Copying the Gene Sequence
Polymerase Chain Reaction (PCR) is a technique used to make many copies of a desired gene. Steps to PCR DNA strands are separated by heating. Short pieces of DNA, called primers, are attached to the DNA strands to prepare a place for DNA polymerase to start copying. These copies serve as templates for more copies.
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DNA parent strand is separated.
Polymerase Chain Reaction Polymerase Chain Reaction (PCR) is a technique used to make many copies of a desired gene. Steps to PCR DNA strands are separated by heating. Short pieces of DNA, called primers, are attached to the DNA strands to prepare a place for DNA polymerase to start copying. These copies serve as templates for more copies. DNA parent strand is separated. Primers are attached. Copies are made.
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Changing DNA Recombinant DNA Technology
Joining together DNA from two or more sources. This makes it possible to change the genetic composition of living organisms. DNA of one organism is extracted and cut into pieces. A piece that produces a desired protein is inserted into another organism’s DNA. The organism with the new piece of DNA produces the desired protein.
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Plasmids and Genetic Markers
Bacteria are commonly used in Recombinant DNA technology because they contain a circular piece of DNA, called a plasmid, in addition to their own chromosomes. Joining DNA to a plasmid, and then using the recombinant plasmid to transform bacteria, results in the replication of the newly added DNA along with the rest of the cell’s genome. Plasmid’s contain genetic marker’s which make it possible to easily identify the recombined plasmid amongst millions of cells.
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Transgenic Organisms Transgenic organisms can be produced by the insertion of recombinant DNA into the genome of a host organism. Genetic engineers can now produce transgenic plants, animals, and microorganisms.
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Transgenic Bacteria
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Transgenic Plants
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Cloning Cloning is the creation of genetically identical organisms.
A clone is a member of a population of genetically identical cells produced by a single cell.
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“Dolly” First cloned mammal to survive. 277th attempt.
“Dolly” was an important break through. She was euthanized at age 6 because she was suffering from lung cancer and cripling arthritis.
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How to get a clone in 4 easy steps
1. Remove the nucleus of an egg
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How to get a clone in 4 easy steps
2. Fuse egg with a cell taken from another organism. 3. Place in the uterus of a foster mother. 4. Foster mother gives birth to cloned baby.
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Donor Nucleus Fused Cell Egg Cell Embryo
These two cells are fused using an electric shock. Fused Cell Egg Cell The nucleus of the egg cell is removed. An egg cell is taken from an adult female sheep. Embryo The embryo is placed in the uterus of a foster mother. The embryo develops normally into a lamb—Dolly The fused cell begins dividing normally.
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We have also cloned Cows Pigs Mice Cats Dogs Horse Monkey
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Starlight
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The cutest clone First cloned cat “CC”
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Cloned Mice Egg Donor Nucleus Donor Surrogate Mother Cloned babies
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Female gives birth to her own dam twin!
Dam = female horse
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The worlds first cloned dog
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The latest clones Will be used to study stem cells and animal to human transplants.
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Breaking News in the Cloning World!
Scientists recently announced that for the first time, they have successfully cloned a rhesus monkey embryo.
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Benefits of Human Cloning
Allow childless couple to have a child with their DNA. Tissues and organs for transplant. Treatment of diseases like Alzheimer’s or Parkinson’s. Several copies of genetically altered cells. Saving endangered species.
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Concerns of Human Cloning
Cloned animal’s have genetic defects. Health problems. Opposition to interference with reproduction. Doctor’s playing “God”. Many attempts would die. Children born with severe deformities. Trying to create Super humans. Diminished self – esteem. Currently - Fertility clinic in Texas using technology to ensure male or female offspring.
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Should we reproductively clone humans?
It took nearly 300 tries on Dolly. Success rate of .4 on the horse. Success rate of 1.6 on the dog. How many humans would die before this worked?
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Stem Cells Undifferentiated cells that can grow into specialized cells. A cell whose job is not yet determined. Other cells “stem” from these types of cells. Stem cells wait in the body until they get a signal to differentiate into specific cells within your body. Ex. Heart, skin, brain
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Where do Stem Cells Come From?
Adult Stem cells exist in adults, children, and umbilical chords but in very limited numbers. Not ideal for research due to low numbers and due to the fact that some differentiation has occured. Embryonic stem cells have the highest potential for research. A 4 to 5 day old embryo called a blastocyt has a group of 150 or more stem cells that have not yet differentiated. Basically a blastocyt is a fertilized egg grown in a petri dish.
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Cloning member of a population of genetically identical organisms produced from a single cell
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15.3 Applications of Genetic Engineering
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Agriculture and Industry
Ideally, genetic modification could lead to better, less expensive, and more nutritious food as well as less-harmful manufacturing processes.
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GM Foods GM crops have become an important component of our food supply. Genetically modified foods are not regulated in the United States. The FDA (Food and Drug Administration) does not require labeling on genetically modified foods.
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GM Animals Some examples of GM Animals include:
Recombinant Bovine Growth Hormone increases milk production in dairy cows. Pigs modified to produce more lean meat. Salmon injected with growth hormone to grow faster. Chicken injected with estrogen which increases breast size.
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Transgenic Organisms Term used to refer to an organism that contains genes from other organisms. Organisms that have been genetically modified.
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Transgenic Animals Mice susceptible to cancer for research.
Mice made to have human immune systems. Livestock with growth hormone. Chickens resistant to bacterial infections that cause us food poisoning. Mad cow resistant cows. Sheep and pigs that produce our proteins. Spider web goats.
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Transgenic Animals Mice susceptible to cancer
Mice made to have human immune systems Livestock with growth hormone Chickens resistant to bacterial infections that cause us food poisoning Mad cow resistant cows Sheep and pigs that produce our proteins Spider web goats
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Spider Web Goats? Take the gene for making spider web silk
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Put it in a goat Then milk it Extract the spider web silk in large quantities… And we could have…
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The best bullet proof vest ever!
Strongest steel cables And much more…
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Transgenic Plants Already here, already controversial.
Here are some facts and myths.
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25 percent of corn is genetically modified.
Percentage of GM crops. 25 percent of corn is genetically modified.
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Insect Resistant The bulk of both GM soy beans and corn is modified to have a natural insecticide.
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Herbicide resistant Resist weed killing chemicals.
Organic farmers sued farmers using roundup crops for fear of contamination to organic crops and lost.
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Transgenic Plant Myths
The fish tomato and the fish berry. Genetically modify plants to have a fish gene that makes them able to live in colder temperatures. Experimentally tested, but never worked.
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A Rising Trend As more and more farmers are realizing the efficiency of these GM plants, the more they will be used.
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Biotechnology Applications in Health and Medicine
Preventing Disease Provitamin A rich Golden Rice will hopefully prevent problems caused by infant malnutrition. Transgenic plants and animals to produce human antibodies. Transgenic sheep and pigs to produce human proteins.
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Biotechnology Applications in Health and Medicine
Medical Research Transgenic animals with human immune systems for researching cures and organ growth for transplants.
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Biotechnology Applications in Health and Medicine
Treating Disease Genetically engineered bacteria produce human growth hormone, insulin, blood clotting factors, cancer fighting molecules such as interleukin-2 and interferon. Gene Therapy is the process of changing an absent or faulty gene to treat a medical disease or disorder.
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Gene Therapy A defective protein is replaced with a good one, eliminating the symptoms of the disease. Insertion of a new “healthy” gene into the organism to provide needed (usually) proteins, hormones etc. Gene is carried into the host by a viral vector (like the flu virus) that has been disabled. Can provide relief for many genetic diseases. Gene therapy research is ongoing with cystic fibrosis, gout, rickets, sickle-cell anemia, and inherited high cholesterol. Problems: immune responses to the virus,cancer
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Transgenic Microorganisms
Before: Diabetics had to use insulin from cadavers. Now: We make bacteria that produce human proteins such as insulin, growth hormone, clotting factor. Future: Bacteria may produce substances to fight cancer, make raw materials for plastic and fibers.
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Transgenic bacteria produce human insulin.
Diabetes is a disease in which the human body doesn’t properly produce insulin. Insulin is a hormone necessary to break down carbohydrates in the blood stream for use in cellular respiration. No carbs for cellular respiration means no ATP energy for cells. Diabetics inject insulin into their bodies to replace the insulin that is supposed to be produced.
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How it works
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The solution - how can we get lots of insulin?
Other animals? Get something less cute to make it for us using the gene for insulin.
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Bacteria – E. coli Transformation
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The gene for insulin is isolated and
removed from human DNA leaving it with sticky ends. A plasmid from the bacteria E coli is removed and cut open using restriction enzymes. The insulin gene is inserted into the bacterial plasmid using DNA ligase. The recombinant plasmid is taken up by the bacteria by transformation. The bacteria reproduces, making copies of the gene each time, allowing lots of insulin to be produced.
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Biotechnology Applications in Health and Medicine
Genetic Testing Now available for diagnosing hundreds of disorders.
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Biotechnology Applications in Health and Medicine
Examining active genes Examining active genes in different cells helps scientists to understand how cells function normally and what happens when genes don’t work as they should. DNA microarray technology enables scientists to study thousands of genes at once to understand their activity level.
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Biotech Products in Use
Anemia, chemotherapy effects Blood clot remover, diabetic treatment Treatment of Multiple Sclerosis Gaucher’s Disease lysosomal storage genetic defect Epogen,neupogen (Amgen) TPA, Insulin (Genentech) Interferon Beta (Biogenidec) Algucerase (Genzyme)
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Personal Identification
DNA fingerprinting Analyzes sections of DNA that may have little or no function but vary widely from one individual to another. These DNA samples can be separated using gel electrophoresis. The number and position of bands formed on each lane of gel is the actual genetic "fingerprint" of that DNA sample. Each individual has a unique DNA fingerprint (except for identical twins). DNA fingerprinting has revolutionized forensics. Paternity testing utilizes DNA fingerprinting.
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DNA Fingerprinting
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15.4 Ethics and Impacts of Biotechnology
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Profits and Privacy Patenting Life Genetic Ownership
Patent holders sometimes demand high fees that block other scientists from exploring certain lines of research. Do you have exclusive rights to your DNA? Should you, like patent holders, be able to keep your genetic information confidential? Should genetic sequences be patented? Genetic Ownership The United States Congress passed the Genetic Information Nondiscrimination Act in The act protects Americans against discrimination based on their genetic information. EX. Health insurance companies, employers
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Safety of Transgenics Pros of GM Foods Cons of GM Foods
Careful studies of GM foods have provided no scientific support for concerns about their safety , and it does seem that foods made from GM plants are safe to eat. (At least that is what the companies marketing the products claim. The other side doesn’t have enough money or the research facilities to undergo such large scale research.) Cons of GM Foods GM foods are not required to undergo special safety testing before entering the market. No additional labeling is required to identify a product as genetically modified.
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Negative Effects of Genetically Modified Foods
Artificially introduced proteins may cause allergic reactions in people with allergies. Recombinant Bovine Growth Hormone (rGBH) increases udder infection causing milk to contain increased levels of pus, fat, and bacteria. Antibiotics are given to the cows and then passed to their milk and consumed by people causing antibiotic resistant bacteria to thrive. rBGH causes increased production of another hormone which at high levels can cause cancer. Herbicide and pesticide resistant crops are over sprayed with weed killer causing everything but the crop to die. The crops then absorb the weed killer which is passed on to the consumer who eats the crop.
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Negative Effects of Genetically Modified Foods
Destruction of plant life surrounding the crops destroys the habitats of many beneficial insects and the animals that survive on the insects such as birds. Seeds of genetically modified plants are unable to reseed themselves naturally so the farmer must purchase new seeds when it is time to replant. GM foods have been linked to ADD, ADHD, earlier onset of puberty in females, inability to concentrate, cancer, etc. The hormone estrogen is changing puberty and physical appearance of male and female adolescents.
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Organic Foods Organic foods are foods manufactured and grown with no pesticides, hormones, genetic modification, etc. They are all natural. Industries that market organic foods are growing in popularity as more and more people become aware of exactly what they are consuming in a GM product. However, organically grown products are often smaller in size and more expensive.
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Ethics of New Biology Just because we have the technology to modify and organism’s characteristics, are we justified in doing so?
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Fun With Fireflies There is an enzyme that makes fireflies glow
Luciferase Could we take a gene out of an animal and put it in something else? Could we get things that don’t glow, to glow
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Glowing Tobacco Plant Put luciferase gene in a tobacco plant and you can get a glowing tobacco plant
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Glow - Fish
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Glow - Mice
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