Genetic Genetic EngineeringEngineering

Chapter 13Chapter 13

Changing the Living Changing the Living WorldWorld•Selective Selective

breedingbreeding– Breeding animals Breeding animals

with characteristics with characteristics we want to produce we want to produce offspring with thoseoffspring with those•Plants – Potatoes or Plants – Potatoes or flowersflowers

•Animals – dogs or Animals – dogs or farm animalsfarm animals

Changing the Living Changing the Living WorldWorld– HybridizationHybridization

•Cross different Cross different individuals to get individuals to get offspring with offspring with favorable traits favorable traits

•The result is a The result is a hybridhybrid – an – an individual produced individual produced from the crossing from the crossing of two different of two different organisms.organisms.

Changing the Living Changing the Living WorldWorld– InbreedingInbreeding

•Breed similar individuals over and Breed similar individuals over and over to get offspring with favorable over to get offspring with favorable traits traits

Changing the Living Changing the Living WorldWorld

• Increasing Increasing variationvariation– Inducing Inducing

mutations mutations •Radiation Radiation •Chemicals Chemicals

– Produce Produce mutantsmutants – an individual – an individual showing the showing the mutationmutation

Changing the Living Changing the Living WorldWorld

– Producing new Producing new bacteriabacteria•Small size Small size allows for allows for millions to be millions to be treatedtreated– Oil eating Oil eating

bacteriabacteria

Changing the Living Changing the Living WorldWorld– Producing new Producing new

plantsplants•Chemicals that Chemicals that prevent prevent chromosomal chromosomal separationseparation– PolypoidyPolypoidy

•Larger and Larger and stronger plantsstronger plants

13-2 Manipulating 13-2 Manipulating DNADNA

•How can scientists How can scientists manipulate the manipulate the code?code?

•Scientists use their Scientists use their knowledge of the knowledge of the structure of DNA structure of DNA and its chemical and its chemical properties to study properties to study and change DNA and change DNA molecules.molecules.

13-2 Manipulating 13-2 Manipulating DNADNA• Tools of Molecular Tools of Molecular

BiologyBiology– Genetic Genetic

EngineeringEngineering• Making changes in Making changes in

the DNA code of a the DNA code of a living organismliving organism

– DNA ExtractionDNA Extraction• Open a cell Open a cell

(mechanical and (mechanical and chemical methods)chemical methods)

• Use a chemical to Use a chemical to separate the DNA separate the DNA from the rest of the from the rest of the cell parts (an cell parts (an alcohol)alcohol)

13-2 Manipulating 13-2 Manipulating DNADNA– Cutting DNACutting DNA

•DNA molecules DNA molecules are very longare very long

•Restriction Restriction enzymesenzymes– Enzymes that Enzymes that

cuts DNA at a cuts DNA at a specific sequence specific sequence of nucleotidesof nucleotides

•Sticky endsSticky ends – – these are the cut these are the cut ends of the DNAends of the DNA

13-2 Manipulating 13-2 Manipulating DNADNA

– Separating DNASeparating DNA• Gel Gel electrophoresiselectrophoresis– A mixture of DNA A mixture of DNA

fragments is placed fragments is placed at one end of a at one end of a porous gel (negative porous gel (negative end), and an electric end), and an electric voltage is applied to voltage is applied to the gelthe gel

– The molecules will The molecules will move from negative move from negative to positiveto positive

13-2 Manipulating 13-2 Manipulating DNADNA

13-2 Manipulating 13-2 Manipulating DNADNA

•Using the DNA Using the DNA SequenceSequence– Once it is Once it is

separated it is separated it is manageablemanageable•It can now be It can now be

– ReadRead– StudiedStudied– ChangedChanged

13-2 Manipulating 13-2 Manipulating DNADNA

– Reading the Reading the SequenceSequence•How do you read How do you read unknown DNA?unknown DNA?

•You can use:You can use:– DNA PolymeraseDNA Polymerase– Four nucleotidesFour nucleotides– Chemical Chemical

markersmarkers

13-2 Manipulating 13-2 Manipulating DNADNA

– Cutting and Cutting and PastingPasting•DNA synthesizersDNA synthesizers

– Enzymes join Enzymes join artificial pieces of artificial pieces of DNA with natural DNA with natural piecespieces

– Recombinant DNARecombinant DNA• Enzymes join Enzymes join

genes from one genes from one strand of DNA strand of DNA with genes from with genes from another strand of another strand of DNA DNA

13-2 Manipulating 13-2 Manipulating DNADNA

•Making CopiesMaking Copies– PCR or PCR or Polymerase Polymerase chain reactionchain reaction•Photocopying Photocopying DNA over and DNA over and overover

•Use strands of Use strands of DNA that are DNA that are called called primersprimers

13-3 Cell 13-3 Cell TransformationTransformation•TransformatiTransformati

onon– When a cell When a cell

takes in takes in foreign DNA foreign DNA and joins it and joins it with the with the existing DNAexisting DNA

– This external This external DNA becomes DNA becomes part of the part of the cells DNAcells DNA

13-3 Cell 13-3 Cell TransformationTransformation

• Transforming Transforming BacteriaBacteria– Foreign DNA is joined Foreign DNA is joined

to plasmidto plasmid• PlasmidPlasmid – small, – small,

circular DNA moleculecircular DNA molecule•Genetic markerGenetic marker – a – a

gene that makes it gene that makes it possible see which possible see which bacteria are carrying bacteria are carrying the plasmid (that is the plasmid (that is marked) and which marked) and which bacteria are not.bacteria are not.

13-3 Cell 13-3 Cell TransformationTransformation• Transforming Plant Transforming Plant

CellsCells– Using bacterium that Using bacterium that

normally infect plant normally infect plant cells and cause tumorscells and cause tumors

– Taking away the cell Taking away the cell wall some plant cells wall some plant cells will take up DNA on will take up DNA on their owntheir own

– If successful If successful recombinant DNA will recombinant DNA will be found in a be found in a chromosome of the chromosome of the cellcell

13-3 Cell 13-3 Cell TransformationTransformation

• Transforming Transforming Animal CellsAnimal Cells– DNA can be DNA can be

injected directly injected directly into the nucleus into the nucleus of an eggof an egg

– Enzymes help Enzymes help insert the new insert the new DNA into the eggs DNA into the eggs existing DNAexisting DNA

– New DNA New DNA contains markers contains markers that tell which that tell which cells picked up cells picked up the DNAthe DNA

13-4 Applications of 13-4 Applications of Genetic EngineeringGenetic Engineering

• Transgenic Transgenic OrganismsOrganisms– Organisms that Organisms that

contain genes from contain genes from other speciesother species

– Firefly and tobacco Firefly and tobacco plantplant

– Genetic engineering Genetic engineering has increased the has increased the growth of growth of biotechnologybiotechnology

13-4 Applications of 13-4 Applications of Genetic EngineeringGenetic Engineering

– Transgenic Transgenic microorganismsmicroorganisms•Bacteria Bacteria reproduce quicklyreproduce quickly

•Uses:Uses:– Can grow human Can grow human

proteinsproteins•Insulin, growth Insulin, growth

hormone, and hormone, and clotting factorclotting factor

13-4 Applications of 13-4 Applications of Genetic EngineeringGenetic Engineering

– Transgenic Transgenic AnimalsAnimals•Mimic human body Mimic human body for testingfor testing

•Faster growing Faster growing animalsanimals

•No more food No more food poisoningpoisoning

•Grow human Grow human proteinsproteins

13-4 Applications of 13-4 Applications of Genetic EngineeringGenetic Engineering

13-4 Applications of 13-4 Applications of Genetic EngineeringGenetic Engineering

– Transgenic PlantsTransgenic Plants•Natural insecticideNatural insecticide•Resist weed killing Resist weed killing chemicalschemicals

•Food resistant to Food resistant to spoilingspoiling

•Weather resistant Weather resistant plantsplants

•Grow vitamins or Grow vitamins or proteinsproteins

13-4 Applications of 13-4 Applications of Genetic EngineeringGenetic Engineering

• CloningCloning– Clone - A member Clone - A member

of a population of of a population of genetically genetically identical cells identical cells produced from a produced from a single cellsingle cell

– Dolly – The cloned Dolly – The cloned sheep from 1997sheep from 1997

– Save endangered Save endangered speciesspecies