Chapter 13: Genetic Chapter 13: Genetic EngineeringEngineering

13-1: Changing the Living World13-1: Changing the Living WorldHumans use selective breeding to pass desired traits on to Humans use selective breeding to pass desired traits on to the next generation of organisms.the next generation of organisms.

Takes advantage of naturally occurring genetic variations Takes advantage of naturally occurring genetic variations in plants, animals, and other organisms.in plants, animals, and other organisms.

Nearly all domestic animals have been produced this way.Nearly all domestic animals have been produced this way. Horses, cats, farm animals, and crop plantsHorses, cats, farm animals, and crop plants

Every breed of dog is still the same species.Every breed of dog is still the same species.What does this mean?What does this mean?Have been bred for thousands of yearsHave been bred for thousands of years

Better hunters, retrievers, companionsBetter hunters, retrievers, companions Many phenotypic variations, behaviors, and levels of intelligenceMany phenotypic variations, behaviors, and levels of intelligence

13-1: Changing the Living World13-1: Changing the Living WorldBreeding strategiesBreeding strategies1. selective1. selective: selecting a few : selecting a few individuals to serve as parents for individuals to serve as parents for the next generationthe next generation

Have desirable traits.Have desirable traits.

2. hybridization: a cross between : a cross between dissimilar individualsdissimilar individualsBest traits of both parentsBest traits of both parentsOften stronger/hardier than parentsOften stronger/hardier than parentsCombine disease resistance of one Combine disease resistance of one parent with food producing capacity parent with food producing capacity of the other parent.of the other parent.

Breeding StrategiesBreeding Strategies

3. inbreeding: crossing individuals with : crossing individuals with similar characteristics so those similar characteristics so those characteristics will appear in the offspringcharacteristics will appear in the offspring

mutagens: agents, such as radiation and : agents, such as radiation and chemicals, which lead to mutationschemicals, which lead to mutations

A Zonkey!?!A Zonkey!?!

Zebroid – cross between a zebra and an equine.Charles Darwin recorded several of these animals in his travels during the mid 1800s

Mule – cross between a male donkey and a female horse

More patient, sure-footed, and longer-lived than a horseFaster and more intelligent than donkeys

New Kinds of OrganismsNew Kinds of Organisms

BacteriaBacteria

Treated with radiation Treated with radiation or chemicals.or chemicals.

Medical and Medical and environmental environmental applications.applications.

Polyploidy very useful Polyploidy very useful in plants.in plants.

Prevent chromosomal Prevent chromosomal separation during separation during meiosis.meiosis.

EXAMPLES EXAMPLES

Gamma Radiation has produced Gamma Radiation has produced Virus resistant strains of cocoa bean treesVirus resistant strains of cocoa bean trees Disease resistance bean plantsDisease resistance bean plants Red grapefruit containing compounds to Red grapefruit containing compounds to

assist in the absorption of medicinal drugsassist in the absorption of medicinal drugs Dwarf rice that produces 4 times the riceDwarf rice that produces 4 times the rice

Shorter height means less spoilage.Shorter height means less spoilage.

EXIT PASS Feb 4EXIT PASS Feb 4

Which breeding process would you use to Which breeding process would you use to produce these organisms?produce these organisms?

Describe the parents for each example.Describe the parents for each example.

1. Cows that can produce the greatest amount of 1. Cows that can produce the greatest amount of milk.milk.

2. Tall oak trees that can survive a gypsy moth 2. Tall oak trees that can survive a gypsy moth infestation.infestation.

3. Bean plants that can be grown in cold weather 3. Bean plants that can be grown in cold weather environments. environments.

EXIT PASS Feb 4EXIT PASS Feb 4

1. Inbreeding1. Inbreeding Select cows that have the highest milk yield Select cows that have the highest milk yield

and breed them.and breed them.

2. Hybridization2. Hybridization Identify specimens that are not preyed upon Identify specimens that are not preyed upon

by gypsy moths and cross them with the by gypsy moths and cross them with the tallest oak trees.tallest oak trees.

3. Inbreeding3. Inbreeding Identify plants that thrive in cold temperatures Identify plants that thrive in cold temperatures

and breed them.and breed them.

DO NOWDO NOW

Compare inbreeding to hybridization.Compare inbreeding to hybridization.

What are the benefits and drawbacks to What are the benefits and drawbacks to each process?each process?

13-2 Manipulating DNA13-2 Manipulating DNA

Genetic Engineering: Makes changes in an organism’s DNA.

Requires1. Knowledge and structure of DNA2. Chemical properties of DNA2. Chemical properties of DNA3. 3. Techniques to

extract DNA from cellscut DNA in smaller piecesidentify sequences of nucleotidesmake unlimited copies of DNA

Selective BreedingSelective Breeding

Watch the following video clip.Watch the following video clip.

http://www.youtube.com/watch?http://www.youtube.com/watch?v=gWur8Rbc3hcv=gWur8Rbc3hc

IN YOUR NOTEBOOKS…IN YOUR NOTEBOOKS…

What is EUGENICS?What is EUGENICS?

Do you agree or disagree with the principles Do you agree or disagree with the principles of EUGENICS?of EUGENICS?

Explain your answer.Explain your answer.

DNA ExtractionDNA Extraction

Simple chemical proceduresSimple chemical procedures

Cell membranes are broken down.Cell membranes are broken down.

Chemical solutions are added to remove Chemical solutions are added to remove proteins from the DNA.proteins from the DNA.

DNA is separated and isolated from other DNA is separated and isolated from other cell parts.cell parts.

13-2 MANIPULATING DNA13-2 MANIPULATING DNA

Restriction enzymes: proteins capable of : proteins capable of cutting genes at specific DNA sequencescutting genes at specific DNA sequences

Hundreds of different Hundreds of different

onesones

LOCK and KEY LOCK and KEY

(must match exactly)(must match exactly)

Recombinant DNARecombinant DNA

Sequences of DNA combined from two Sequences of DNA combined from two different sources.different sources.

DNA “synthesizers” produce short DNA “synthesizers” produce short sequences of synthetic DNAsequences of synthetic DNA

Enzymes splice together synthetic DNA Enzymes splice together synthetic DNA and natural DNAand natural DNA

DNA fragments cutDNA fragments cut

Combined with Combined with DNA from another DNA from another organismorganism

Gel ElectrophoresisGel Electrophoresis

Mixture of DNA fragments placed at one end of a Mixture of DNA fragments placed at one end of a porous gel.porous gel.

Electric voltage applied to the gel.Electric voltage applied to the gel.

Negatively charged DNA molecules move to Negatively charged DNA molecules move to opposite end of gel.opposite end of gel.

Smaller fragments move faster and fartherSmaller fragments move faster and farther

Compares genomes of different organismsCompares genomes of different organisms

Locate and identify specific genes.Locate and identify specific genes.

http://www.youtube.com/watch?v=3i-DxJ3oJzEhttp://www.youtube.com/watch?v=3i-DxJ3oJzE

Reading DNAReading DNAUnknown single strand of DNA, 4 nucleotide bases, Unknown single strand of DNA, 4 nucleotide bases, and DNA Polymerase added into a test tube.and DNA Polymerase added into a test tube.

Different colored chemical dyes are attached to a Different colored chemical dyes are attached to a few of the bases.few of the bases.

Colored strands separated using electrophoresisColored strands separated using electrophoresis..

Order and size of colored bands identifies unknown Order and size of colored bands identifies unknown nucleotides.nucleotides.

Polymerase Chain ReactionPolymerase Chain ReactionPCR was developed by Kary Mullis in the 1980sPCR was developed by Kary Mullis in the 1980s

Produces many copies of DNAProduces many copies of DNA

STEPS of PCRSTEPS of PCR

1. Add short sequences called primers to end of 1. Add short sequences called primers to end of DNADNA

2. DNA heated to separate the two strands2. DNA heated to separate the two strands

3. Cooled to allow primers to bind to single 3. Cooled to allow primers to bind to single strandsstrands

4. DNA Poly copies single strands4. DNA Poly copies single strands

Process repeatedProcess repeated

Special Poly enzyme found in a bacteria living in Special Poly enzyme found in a bacteria living in hot springs of Yellowstone National Parkhot springs of Yellowstone National Park

PCR AnimationPCR Animation

http://highered.mcgraw-hill.com/sites/http://highered.mcgraw-hill.com/sites/0072556781/student_view0/chapter14/0072556781/student_view0/chapter14/animation_quiz_6.htmlanimation_quiz_6.html

BioluminescenceBioluminescence

Organisms that naturally produce light Organisms that naturally produce light within their bodies.within their bodies.

Chemical compounds mix together to Chemical compounds mix together to create a glow - create a glow - LuciferaseLuciferase Does not require nor generates much heatDoes not require nor generates much heat ““Cold Light”Cold Light”

Incandescence wastes a tremendous Incandescence wastes a tremendous amount of energy to generate enough heat amount of energy to generate enough heat to produce light.to produce light.

13-3 Cell Transformation13-3 Cell TransformationWhat is transformation?What is transformation?

See Figure 13-9 Page 327See Figure 13-9 Page 327

Plasmid – small, circular DNA moleculePlasmid – small, circular DNA molecule Found naturally in some bacteriaFound naturally in some bacteria

Two essentials featuresTwo essentials features Contains a sequence to help promote plasmid Contains a sequence to help promote plasmid

replication.replication. Has a genetic marker to identify plasmid carrying Has a genetic marker to identify plasmid carrying

bacteria from those that do not.bacteria from those that do not.

Markers used for Locating Cells Markers used for Locating Cells Containing PlasmidsContaining Plasmids

Common marker – antibiotic resistant Common marker – antibiotic resistant genegene

DNA carrying resistance gene added to DNA carrying resistance gene added to bacterial culture (millions of bacteria)bacterial culture (millions of bacteria)

1 cell in a million will be transformed1 cell in a million will be transformed

Culture treated with antibiotic to kill Culture treated with antibiotic to kill bacteriabacteria

Only cells with resistance survive.Only cells with resistance survive.

Transforming Plant and Animal Transforming Plant and Animal CellsCells

PLANT CELLSPLANT CELLS

Uses a bacteriumUses a bacterium

Small plasmids are modifiedSmall plasmids are modified

Tumor producing gene removed plasmidTumor producing gene removed plasmid

Foreign DNA is insertedForeign DNA is inserted

Recombinant plasmid now infects plantRecombinant plasmid now infects plant

In culture (naturally) or injectedIn culture (naturally) or injected

Plasmid DNA integrated into Plasmid DNA integrated into chromosomes of transformed cells.chromosomes of transformed cells.

Transforming Plant and Animal Transforming Plant and Animal CellsCells

ANIMALSANIMALS

DNA directly injected into the nucleus of egg DNA directly injected into the nucleus of egg cell.cell.

Enzymes help insert foreign DNA into Enzymes help insert foreign DNA into chromosomes of cell.chromosomes of cell.

Foreign DNA contains markers to identify Foreign DNA contains markers to identify transformed cells.transformed cells.

Gene replacement techniques allow scientists to Gene replacement techniques allow scientists to remove/replace specific genes.remove/replace specific genes.

SEE Figure 13-11 Page 329SEE Figure 13-11 Page 329

13-4 Applications13-4 Applications

Biotechnology – the application of organisms to Biotechnology – the application of organisms to develop and make useful products.develop and make useful products.

Transgenic Organisms - organisms that contain Transgenic Organisms - organisms that contain foreign DNAforeign DNA

transgenic bacteria, plants, and animalstransgenic bacteria, plants, and animals

Transgenic OrganismsTransgenic OrganismsMicroorganisms – produce important Microorganisms – produce important substances for health and industrysubstances for health and industry Reproduce rapidly and easy to growReproduce rapidly and easy to grow Transformed E. coli produce human insulinTransformed E. coli produce human insulin

Animals – used to study genes and improve Animals – used to study genes and improve the world’s food supplythe world’s food supply Mice with human immune systemsMice with human immune systems Food animals immune to diseasesFood animals immune to diseases

Plants – genetically modified (GM) cropsPlants – genetically modified (GM) crops Produce natural insecticides and resistant to Produce natural insecticides and resistant to

weed-killing chemicals.weed-killing chemicals.

The FUTUREThe FUTUREMicroorganisms – substances to fight cancerMicroorganisms – substances to fight cancer raw materials for synthetics and plasticsraw materials for synthetics and plastics

Animals – Provide human proteinsAnimals – Provide human proteins Sheep and pigs produce proteins in their milkSheep and pigs produce proteins in their milk

Plants – produce human antibodies, plastics, Plants – produce human antibodies, plastics, and foods resistant to rotand foods resistant to rot GM rice containing vitamin A already being GM rice containing vitamin A already being

grown in many nations struggling with hunger grown in many nations struggling with hunger and poverty.and poverty.

CloningCloning

Clone – a member of a population of Clone – a member of a population of genetically identical cells produced from a genetically identical cells produced from a single cell.single cell.

1997 – Scottish scientist Ian Wilmut 1997 – Scottish scientist Ian Wilmut cloned “Dolly” the sheep.cloned “Dolly” the sheep.

Cows, pigs, and other mammals have laso Cows, pigs, and other mammals have laso been cloned.been cloned.

Wilmut’s TechniqueWilmut’s TechniqueNucleus of an egg cell removedNucleus of an egg cell removed

Fused with a cell from another adultFused with a cell from another adult Requires electric shockRequires electric shock

Fused cell begins to divideFused cell begins to divide

Developing embryo placed in the reproductive Developing embryo placed in the reproductive system of a foster mothersystem of a foster mother

Embryo develops normallyEmbryo develops normally

Cloned OrganismsCloned OrganismsDolly – “The world’s most famous sheep”Dolly – “The world’s most famous sheep”

Born July 5, 1996Born July 5, 1996

Died February 14, 2003Died February 14, 2003

Causes: Progressive lung disease and severe arthritisCauses: Progressive lung disease and severe arthritis

Remains on display at the Museum of ScotlandRemains on display at the Museum of Scotland

SAVING ENDANGERED SPECIES

Pyrenean IbexNative Habitat: Pyrenees Mountains in France and SpainStatus: Extinct - January 6, 2000Cloning Attempt: 2009 – One clone born alive but died seven minutes later due to lung defects.

Cloning HumansCloning Humans

Highly CONTROVERSIAL!!!Highly CONTROVERSIAL!!! Moral and ethical issuesMoral and ethical issues

The benefits of such procedures are The benefits of such procedures are questionable.questionable. Many cloned animals suffer from genetic Many cloned animals suffer from genetic

defects.defects.

As technology improves… It will become a As technology improves… It will become a more pressing issue.more pressing issue.