IS THIS FOR REAL? What are the advantages? What are the disadvantages? Is it right to create an animal like this simply to make our lives easier?

Transcription

1 NOTES:

2 IS THIS FOR REAL? What are the advantages? What are the disadvantages? Is it right to create an animal like this simply to make our lives easier?

3 GENETIC ENGINEERING IS THE PROCESS OF MAKING CHANGES TO DNA IN ORDER TO CHANGE THE WAY LIVING THINGS WORK. CREATES NEW CROPS AND FARM ANIMALS. MAKES BACTERIA THAT CAN PRODUCE MEDICINES. CAN GROW HUMAN BODY PARTS. CAN PREVENT GENETIC DISEASES, CHANGE HUMANS.

4 ALTERING ORGANISMS ISN T NEW, WE VE BEEN DOING IT FOR 1000 S OF YEARS IT S CALLED - SELECTIVE BREEDING.

5 SELECTIVE BREEDING IN DOGS

6 RECENT PRODUCT OF SELECTIVE BREEDING: THE LABRADOODLE CROSSING A POODLE AND A LABRADOR RESULTS IN A LABRADOODLE WHAT FEATURES HAS THE LABRADOODLE INHERITED FROM THE LABRADOR? WHAT FEATURES HAS THE LABRADOODLE INHERITED FROM THE POODLE? + Poodle + Labrador Labradoodle

7 LABRADOODLE CHARACTERISTICS LARGE (LIKE THE LABRADOR); FLUFFY COAT (LIKE THE POODLE) WHICH SHEDS MUCH LESS THAN A LABRADOR S COAT. LIKE BOTH BREEDS, THEY ARE: GENERALLY WELL TEMPERED; GOOD SWIMMERS. SO THE LABRADOODLE HAS FAVORABLE CHARACTERISTICS FROM BOTH OF ITS PARENT BREEDS. Labradoodle

8 SELECTIVE BREEDING IS A PROCESS USED TO PRODUCE DIFFERENT BREEDS OF ANIMALS OR VARIETIES OF PLANTS THAT HAVE USEFUL CHARACTERISTICS. USING SELECTIVE BREEDING YOU CAN PRODUCE A SPECIFIC OFFSPRING WITH USEFUL CHARACTERISTICS OF BOTH PARENTS. WHAT ORGANISMS DO FARMERS SELECTIVELY BREED?

9 SELECTIVE BREEDING FARMERS CAN MATE SPECIFIC COWS IN TO PRODUCE A GENERATION OF COWS THAT WILL YIELD MORE MILK. FARMERS COULD ALSO SELECTIVELY BREED FOR DOCILE ANIMALS. APPLE GROWERS WANT TO PRODUCE A TYPE OF APPLE THAT IS TASTY AND RESISTANT TO DISEASE. THIS CAN BE DONE BY CROSSING A VARIETY OF APPLE KNOWN FOR TASTE WITH ANOTHER VARIETY THAT SHOWS STRONG RESISTANCE TO DISEASE.

10 ANOTHER EXAMPLE: DAIRY COWS IF YOU WANTED A VARIETY OF COW THAT PRODUCED A LOT OF MILK, YOU WOULD: SELECT THE COWS IN YOUR HERD THAT PRODUCE THE MOST MILK. ALLOW ONLY THESE COWS TO REPRODUCE. SELECT THE OFFSPRING THAT PRODUCE THE MOST MILK. ONLY LET THESE OFFSPRING REPRODUCE. KEEP REPEATING THE PROCESS OF SELECTION AND BREEDING UNTIL YOU ACHIEVE YOUR GOAL.

11 THE KEY IS TO IDENTIFY THE FEATURE YOU WANT, AND ONLY BREED THE INDIVIDUALS THAT HAVE THAT FEATURE: SELECT PARENTS WITH THE DESIRED TRAITS. CROSS THE PARENTS (BREED THEM). SELECT FROM THE OFFSPRING. REPEAT OVER MANY GENERATIONS. SELECTIVE BREEDING IS USED TO: - CHOOSE THE CHARACTERISTICS OF FOOD. PRODUCE A MORE UNIFORM CROP: SIZE HARVEST TIME EXTEND THE TOLERANCE RANGE OF AN ORGANISM.

12 PERFECT PET IMAGINE YOU WANTED TO CREATE YOUR PERFECT DOG HOW WOULD YOU SELECTIVELY BREED FOR IT? WHAT TWO PARENTS ARE YOU GOING TO CHOOSE? WHAT QUALITIES DO EACH OF THEM HAVE (WHICH YOU WANT) HOW ARE YOU GOING TO GET THESE QUALITIES IN YOUR PET?

13 HOWEVER, THE TRAITS INHERITED ARE RANDOM & UNPREDICTABLE.

14 BUT, WITH GENETIC ENGINEERING: TRAITS ARE SELECTED INTENTIONALLY. OFFSPRING RECEIVE SPECIFIC DNA FROM PARENTS. DESIRED RESULTS ARE ALMOST ALWAYS OBTAINED.

15 Genetic Engineering is: The simple addition, deletion, or manipulation of a single trait in an organism to create a desired change.

16 Major tool of genetic engineering is recombinant DNA. Recombinant DNA (rdna) - DNA joined to other unrelated foreign DNA. Also called gene splicing.

17

18 HOW IS IT DIFFERENT FROM SELECTIVE BREEDING? In selective breeding, we are combining the traits of two organisms randomly. We get a random mixture of their genes, while hoping for the results we seek. We might get what we want. But a bunch of other traits will come along with it.

19 In genetic engineering, a single gene, a half page recipe in the 52-thousand-page set of recipe books, can direct the plant to make new traits. Or it could remove an undesirable trait.

20 Transgenic Organisms: Are organisms that have been altered by genetic engineering. Genetic material changed by other than random natural breeding. Gene transfer - moving a gene from one organism to another.

21 TYPES OF TRANSGENIC ORGANISMS GMO- Genetically Modified Organism. Uses genes not found in the organism to provide new traits. GEO - Genetically Enhanced Organism Uses superior versions of genes already found in the organisms genome.

22 Time for a quick poll: Question #1: Raise your hand if you would eat food (plant or animal) that had been created through genetic modification.

23 Question #2: Raise your hand if you would eat vegetables that had been created through genetic modification but NOT meat.

24 Question #3: Raise your hand if you would eat meat that had been created through genetic modification but NOT vegetables.

25 Question #4: Raise your hand if you would eat both meat & vegetables that had been created through genetic modification.

26 RESULTS FOR A SIMILAR POLL CONDUCTED IN AMERICA

27 WHAT ARE GENETICALLY MODIFIED (GM) FOODS? ( Frankenfoods?) You have probably already eaten GM foods. Some GM tomatoes, for example, have had their genes altered to stop them from going soft while they are still growing. For several years they were widely sold in tomato paste. The GM foods we eat have all been tested for safety. But some people worry about the long term effects of eating genetically modified foods.

28

29 WHAT HAVE I EATEN? Genetically modified (GM) foods possess specific traits such as tolerance to herbicides or resistance to insects or viruses. By most estimates, up to 70% of the processed foods at your local grocery store contain at least one ingredient that s been genetically altered Genetically modified to travel better so don t have to be picked when green better tasting! Genetically modified to reduce being eaten by insects.

30 SAY GOODBYE TO BANANAS According to recent reports, the world may soon be out of bananas. Because of it s unique method of reproduction, banana plantations in Africa, Asia and Central America are uniquely susceptible to fungi, viruses and pests. Unless scientists can find a way to genetically enhance the banana s ability to ward off parasites, we could be banana-less in ten years. Several agroscience companies believe they can genetically engineer such an invincible banana by copying parts of the genetic codes of other fruits and instilling them into the banana.

31 PROS OF GENETIC ENGINEERING: Crops Better taste and quality Less time to ripen. More nutrients, more food, and stress tolerance Improved resistance to disease, pests, and herbicides New products and growing techniques Animals Increased resistance, productivity, hardiness, and feed efficiency Better yields of meat, eggs, and milk Improved animal health and diagnostic methods Environment "Friendly" bioherbicides and bioinsecticides Conservation of soil, water, and energy Better natural waste management More efficient processing Society More food for growing populations

32 SAFETY CONS OF GENETIC ENGINEERING POTENTIAL HUMAN HEALTH IMPACT: ALLERGENS, TRANSFER OF ANTIBIOTIC RESISTANCE MARKERS, UNKNOWN EFFECTS POTENTIAL ENVIRONMENTAL IMPACT: UNINTENDED TRANSFER OF TRANSGENES THROUGH CROSS-POLLINATION, LOSS OF FLORA AND FAUNA BIODIVERSITY ACCESS AND INTELLECTUAL PROPERTY DOMINATION OF WORLD FOOD PRODUCTION BY A FEW COMPANIES INCREASING DEPENDENCE ON INDUSTRALIZED NATIONS BY DEVELOPING COUNTRIES ETHICS VIOLATION OF NATURAL ORGANISMS' INTRINSIC VALUES TAMPERING WITH NATURE BY MIXING GENES AMONG SPECIES OBJECTIONS TO CONSUMING ANIMAL GENES IN PLANTS AND VICE VERSA STRESS FOR ANIMAL LABELING NOT MANDATORY IN SOME COUNTRIES (E.G., U. STATES) MIXING GM CROPS WITH NON-GM CONFOUNDS LABELING ATTEMPTS

33 HOW CAN WE USE GEN. ENG. TO HELP PEOPLE? By inserting a gene for human insulin into an E.Coli bacterium, the E. coli will make tons of insulin, which scientists and doctors can collect and use. Right now, doctors are using pig hearts for transplants but there are still rejection problems. One day soon, scientists will be able to genetically engineer pigs to grow human organs for use in transplants.

34 GM CROPS Crops given extra genes for new and useful characteristics are called genetically modified (GM). What characteristics might be useful in crops? pest resistance frost resistance disease resistance herbicide resistance drought resistance longer shelf life

35 PEST-RESISTANT CROPS Potatoes can be genetically modified so they are toxic to pests, such as the Colorado Beetle. The gene for a powerful bacterial toxin is added to the potato plant. If the beetle tries to eat the potato plant, it is killed by the toxin.

36 FROST-RESISTANT CROPS Crops can be genetically modified so they are resistant to adverse environmental conditions. For example, lettuces could be genetically modified to be resistant to frost. GM lettuce Why are some people against the development and use of GM crops? non- GM lettuce

37 PLANTS WITH EXTRA VITAMINS Rice can be genetically modified to make betacarotene, a substance that is converted into vitamin A in the body. The GM rice is called Golden Rice and is being developed to help fight vitamin A deficiency and blindness in developing countries.

38 WHAT IS GENE THERAPY? 1. In people with cystic fibrosis, one of the genes is faulty and cannot do its job properly. 2. To fix the problem, a copy of the same gene from a healthy person is spliced into a virus. 3. The patient s lungs are infected with the virus. It delivers the working gene into the patient s cells. The cells can then make the right protein, and the patient can breathe normally. Patient s cell Patient s DNA Faulty Gene Virus DNA New working gene Patient s DNA Virus DNA with new gene

39 CLONING: The first animal ever cloned was a sheep named Dolly.

40 Cloning Cats Now cats can have more than nine lives. The company that funded the first successful cloning of a domestic cat, has gone commercial. You can clone your own kitty. Your cost? U.S. $50,000 each.

41 "Cc," the first cat ever cloned at seven weeks old with Allie, her surrogate mother. Cc was cloned by transplanting DNA from a female three-colored calico cat into an egg cell whose nucleus had been removed. Then this embryo was implanted into Allie, the surrogate mother. A genetic match between Cc and the donor mother confirms they are clones.

42

43 MIXING HUMANS AND ANIMALS The mythic beast had a lion's body, serpent's tail, and goat's head. Scientists have begun blurring the line between human & animal by producing chimeras a hybrid creature that's part human, part animal. In 2003, Chinese scientists at the Shanghai Second Medical University successfully fused human cells with rabbit eggs. The embryos were the first successful human-animal chimeras. They were allowed to develop for several days before the scientists destroyed the embryos to harvest their stem cells.

44 In Minnesota researchers at the Mayo Clinic created pigs with human blood flowing through their bodies.

45 At Stanford University in California an experiment is planned to create mice with human brain organization. Scientists feel that, the more humanlike the animal, the better research model it makes for testing drugs or possibly growing "spare parts" to transplant into humans.

46 TRANSGENIC GOATS For example, the gene for a human antibody can be introduced into goats. Additional controlling DNA is also introduced, so the human antibody is only produced in the goat s mammary gland at a certain time. The antibody is then expressed in the goat s milk, where it can be purified and used to treat diseases.

47 The eggs of this transgenic chicken contain a human antibody that could one day help to treat skin cancer. What advantages does this method of producing antibodies have? WHICH CAME FIRST?

48 Scientists at the Oregon Regional Primate Research Center announced the birth of the first genetically engineered primate, named ANDi (for "inserted DNA" spelled backwards). ANDi s cells contain the gene that makes jellyfish glow in the dark. The experiment was something of a flop; ANDi does not glow. ANDI

49 THE SPIDER GOAT, FROM THE UNIVERSITY OF WYOMING, WAS ENGINEERED WITH GENES TO PRODUCE SPIDER SILK IN ITS MILK. THIS IS IMPORTANT BECAUSE SPIDER SILK IS INCREDIBLY STRONG, AND HAS BEEN USED IN KEVLAR VESTS.

50 BOVINE SOMATOTROPIN (BST) BST IS A HORMONE COMPOSED OF PROTEIN THAT IS PRODUCED BY THE COWS PITUITARY GLAND. IT HELPS CONTROL THE PRODUCTION OF MILK BY ASSISTING THE REGULATION OF NUTRIENTS INTO THE PRODUCTION OF MILK OR FAT.

51 BST SUPPLEMENTARY BST CAUSES THE COW TO PRODUCE LESS FAT AND MORE MILK. BY SPLICING GENETIC MATERIAL INTO E. COLI BACTERIA THE HORMONE CAN BE PRODUCED AT RELATIVELY LOW COST.

52 1982 HUMULIN IS APPROVED FOR THE TREATMENT OF DIABETES.

53 1. The flounder s antifreeze gene is copied and inserted into a small ring of DNA taken from a bacteria cell. 2. The DNA ring containing the flounder gene is put into a second bacterium. 3. This second bacterium is used to infect the strawberry cell. The flounder s antifreeze gene enters the strawberry s DNA. 4. The new GM strawberry cell is grown into a GM strawberry plant which can be bred many times. Strawberry cell with Antifreeze gene This diagram shows how one type of GM food, a strawberry that resists frost damage is made. The flounder is a fish that live in icy seas. It has a gene that stops it from freezing to death. Strawberries are soft fruits that can easily be damaged by frost. Wonder what they used to make this one blue? A different gene from another organism. Thanks to the new gene, GM strawberries make a protein which helps them resist frost. They don t contain any other fish genes and, and do not taste or smell of fish.

54 RECOMBINANT DNA THE ABILITY TO COMBINE THE DNA OF ONE ORGANISM WITH THE DNA OF ANOTHER ORGANISM. RECOMBINANT DNA TECHNOLOGY WAS FIRST USED IN THE 1970 S WITH BACTERIA.

55 BASIC STEPS OF GENETIC ENGINEERING STEP 1: DNA ISOLATION ISOLATION OF FOREIGN DNA OR - FINDING THE GENE YOU WANT TO PUT INTO ANOTHER ORGANISM. STEP 2: RECOMBINANT DNA INSERTION OF THIS DNA INTO BACTERIAL PLASMID. STEP 3: TRANSFORMATION INSERTION OF RECOMBINANT PLASMID DNA INTO BACTERIA.

56 STEP 1: ISOLATION OF FOREIGN DNA INVOLVES FINDING THE GENE YOU WANT TO ENGINEER INTO ANOTHER ORGANISM. THEN CUTTING IT OUT OF THE CHROMOSOME (DNA) WITH RESTRICTION ENZYMES THAT PRODUCE STICKY ENDS.

57 STICKY END OF ECOR1 EcoRI G AATTC TTAAG S. Stevens

58 HpaI AT NOT good for engineering. HindIII A AGCTT PstI TCGAA CTGCA G ACGT

59 Step 2: Recombinant DNA Formation Involves cutting the vector DNA (the plasmid or other DNA used to deliver the gene chosen) with the same restriction enzyme. Allowing sticky ends to anneal. Bonding the pieces together with Ligase.

60 RECOMBINANT DNA

61 PLASMID RESTRICTION ENZYME EXAMPLE

62 ISOLATION OF FOREIGN DNA

63 RECOMBINANT DNA FORMATION

64 RECOMBINANT DNA

65 RECOMBINATION INSERTION FOREIGN GENE INTO A HOST BACTERIAL CELL PLASMID. GOAL TO PRODUCE MANY COPIES (CLONES) OF A PARTICULAR GENE. REPORTER GENE / MARKER GENE TAGS GENE OF INTEREST TO IDENTIFY THE PRESENCE OF A GENE. OFTEN AN ANTIBIOTIC RESISTANCE GENE. IMPORTANT FOR IDENTIFYING TRANSFORMED CELLS

66 DISTINGUISHING TRANSFORMED FROM NON- TRANSFORMED CELLS: INVOLVES INCORPORATING AN ANTIBIOTIC RESISTANCE (REPORTER) GENE IN THE PLASMID AND THEN PLATING THE CELLS ON A MEDIUM CONTAINING THAT ANTIBIOTIC. ONLY THE TRANSFORMED CELLS ARE RESISTANT, SO ONLY THEY CAN GROW ON THE MEDIUM.

67 STEP 3 TRANSFORMATION INSERT RECOMBINANT PLASMID INTO BACTERIA. BACTERIA PRODUCED WITH THE RECOMBINANT DNA EXPRESSES THE GENE OF INTEREST.

68 VECTOR THE WAY YOU GET THE DNA INTO THE NEW CELL. EXAMPLES: PLASMIDS VIRUSES BALLISTIC GENE TRANSFER (DNA COATED PARTICLES) EXOGENOUS DNA

69 CHARACTERISTICS OF A VECTOR 1. CAN REPLICATE INDEPENDENTLY IN THE HOST CELL CONTAINS AN ORIGIN SITE. 2. HAS RESTRICTION SITES IN THE VECTOR. 3. HAS A REPORTER GENE THAT WILL ANNOUNCE ITS PRESENCE IN THE HOST CELL. 4. IS A SMALL SIZE IN COMPARISON TO THE HOST CHROMOSOME FOR EASE OF ISOLATION.

70 BALLISTIC GENE TRANSFER - THE USE OF TINY DNA-COATED PROJECTILES AS CARRIERS. IT IS IMPORTANT TO TRANSPORT DNA THROUGH THE WALLS OF INTENDED RECIPIENT CELLS. PROJECTILES ARE OFTEN KNOWN AS MICRO PROJECTILES

71 PLASMIDS WERE DISCOVERED IN THE LATE SIXTIES, AND IT WAS QUICKLY REALIZED THAT THEY COULD BE USED TO AMPLIFY A GENE OF INTEREST. A PLASMID CONTAINING RESISTANCE TO AN ANTIBIOTIC CAN BE A VECTOR. THE GENE OF INTEREST IS INSERTED INTO THE VECTOR PLASMID AND THIS IS THEN PUT INTO E. COLI THAT ARE SENSITIVE TO AMPICILLIN. THE BACTERIA ARE THEN SPREAD OVER A PLATE THAT CONTAINS AMPICILLIN. THE BACTERIA WILL NEED THE PLASMID TO SURVIVE AND IT WILL CONTINUALLY REPLICATE IT, ALONG WITH YOUR GENE OF INTEREST THAT HAS BEEN INSERTED INTO THE PLASMID.

72 S. Stevens

73 TRANSFORMATION - PROCESS OF INTRODUCING FREE DNA INTO BACTERIA. COMPETENT CELL - A CELL THAT IS CAPABLE OF TAKING UP DNA. ELECTROPORATION - THE USE OF AN ELECTRIC SHOCK TO MOMENTARILY OPEN OR DISRUPT CELL WALLS (WHICH ALLOWS DNA TO ENTER THE CELL).

74 COMPETENT CELLS: SINCE DNA IS A VERY HYDROPHILIC MOLECULE, IT WON'T NORMALLY PASS THROUGH A BACTERIAL CELL'S MEMBRANE. IN ORDER TO MAKE BACTERIA TAKE IN THE PLASMID, THEY MUST FIRST BE MADE "COMPETENT" TO TAKE UP DNA.

75 THIS IS DONE BY CREATING SMALL HOLES IN THE BACTERIAL CELLS BY: SUSPENDING THEM IN A SOLUTION OF CALCIUM CHLORIDE. THE CELLS ARE THEN INCUBATED ON ICE. THEY ARE PLACED BRIEFLY IN A HIGH TEMPERATURE (HEAT SHOCK). THEN RETURNED TO ICE. THIS CAUSES THE BACTERIA TO DEVELOP HOLES IN THEIR CELL WALL TO TAKE IN THE DNA.

76 COMPETENCY THE PROCEDURE TO PREPARE COMPETENT CELLS CAN SOMETIMES BE TRICKY. BACTERIA AREN'T VERY STABLE WHEN THEY HAVE HOLES IN THEM, AND THEY DIE EASILY. A POORLY PERFORMED PROCEDURE CAN RESULT IN CELLS THAT AREN'T VERY COMPETENT TO TAKE UP DNA. A WELL- PERFORMED PROCEDURE WILL RESULT IN VERY COMPETENT CELLS. THIS IS TYPICALLY WHERE THE PROCESS FAILED IF CELLS DO NOT TRANSFORM.

77 3 TYPES OF TRANSFORMATION:

78 GENE (OR DNA) CLONING S. Stevens

79 Traditional Cloning is NOT DNA Cloning DNA Cloning (many identical copies of specific DNA molecules) is NOT the same as Organismal Cloning (identical genetic copies of specific individuals).

80 CLONING OF PLASMID

81 2 MAIN PURPOSES OF CLONING: 1. IT ALLOWS FOR A LARGE NUMBER OF RECOMBINANT MOLECULES TO BE PRODUCED FROM LIMITED STARTING MATERIALS. 2. PURIFICATION LIMITING THE PRODUCTION OF EXTRA DNA MOLECULES THAT DO NOT CONTAIN THE TARGET GENE TO BE CLONED.

82 PGLO GFP GREEN FLUORESCENT PROTEIN

83 FLUORESCENT IN THE LABORATORY, FLUORESCENCE IS EASILY ACHIEVED BY EXPOSING THE PROTEIN TO LONG RANGE UV LIGHT OR BLACK" LIGHT. THE FLUOROPHORE ABSORBS LIGHT IN THE UV-B REGION (395 NM.. PLUS A SMALLER ABSORBANCE PEAK AT 470 NM). IT EMITS LIGHT (FLUORESCES) AT 509 NM, WHICH IS IN THE GREEN PART OF THE VISIBLE SPECTRUM.

84 GFP AND LAND MINES NEAL STEWART AT THE UNIVERSITY OF NORTH CAROLINA IS DEVELOPING PLANTS THAT CAN DETECT LAND MINES. PLANTS COULD BE IDEAL BIOSENSORS FOR LAND MINES AS SEEDS WOULD BE SPREAD WIDELY AND EVENLY IN A SUSPECT FIELD. THE GENE THAT CAN ANNOUNCE THE PRESENCE OF LAND MINES IS GFP. THE GENE WILL BE EXPRESSED IN THE PRESENCE OF A LAND MINE.

85 GFP AND MICE

86 GLO FISH FLUORESCENT ZEBRA FISH WERE SPECIALLY BRED TO HELP DETECT ENVIRONMENTAL POLLUTANTS. BY ADDING A NATURAL FLUORESCENCE GENE TO THE FISH, SCIENTISTS ARE ABLE TO QUICKLY AND EASILY DETERMINE WHEN WATERWAYS ARE CONTAMINATED.