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Genetic Engineering and Recombinant DNA Technology • Diversity of life is based on the differences in genes (DNA) • 1 gene = 1 protein = 1 function? If we change the DNA (genes), then it would be possible to change the function of the cell, and ultimately the organism

Genetic Engineering and Recombinant DNA Technology

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Genetic Engineering and Recombinant DNA Technology. Diversity of life is based on the differences in genes (DNA) 1 gene = 1 protein = 1 function? If we change the DNA (genes), then it would be possible to change the function of the cell, and ultimately the organism. - PowerPoint PPT Presentation

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Page 1: Genetic Engineering and Recombinant DNA Technology

Genetic Engineering and Recombinant DNA Technology

• Diversity of life is based on the differences in genes (DNA)

• 1 gene = 1 protein = 1 function?

• If we change the DNA (genes), then it would be possible to change the function of the cell, and ultimately the organism

Page 2: Genetic Engineering and Recombinant DNA Technology

Genetic Engineering and Recombinant DNA Technology

• Recombinant DNA-isolating and combining DNA of one organism with the DNA of a different organism

• Human Insulin gene bacteria• Genetic Engineering-modifying

gene(s) to benefit or cure an organism

• Agriculture crops, animals • Gene therapy: when cloned genes

are used to modify humans, to control genetic diseases sickle cell, hypercholesterolemia

Ice cream anyone?

Page 4: Genetic Engineering and Recombinant DNA Technology

Cloning Genes

• Cloning-production of genetically identical DNA

• To clone a gene, must combine human DNA with another organism’s DNA recombinant DNA

• Put gene into a plasmid extra bacterial chromosome that can accept foreign DNA

Page 5: Genetic Engineering and Recombinant DNA Technology

Molecular Tools Used For Recombinant DNA

• How to combine the DNA from 2 different organisms?

• DNA must be cut and put back together• What kind of molecule could cut DNA and put

it back together again?

Page 6: Genetic Engineering and Recombinant DNA Technology

Molecular Tools Used For Recombinant DNA: Restriction Enzymes

• Bacterial enzymes that cut DNA at specific DNA sequences

• Leaves single stranded tails at the end of the DNA fragments ”sticky ends”

• DNA fragments cut by same enzyme will come together and form a 2x strand DNA fragment; sticky ends are complementary

• DNA ligase closes the “nicks” in the DNA

Page 7: Genetic Engineering and Recombinant DNA Technology
Page 8: Genetic Engineering and Recombinant DNA Technology

Molecular Tools Used For Recombinant DNA: Polymerase Chain Reaction (PCR)

• Multiple copying of a specific DNA sequenceRequires:• primers• Heat insensitive DNA polymerase from Thermus aquaticus (Taq)• Used when only have small amounts of DNA and need to do many

different tests; genetic identification

Cycle 30 =5.37 x 108

Page 9: Genetic Engineering and Recombinant DNA Technology

Genetic Fingerprinting

• Every person has specific DNA sequences that are unique; like fingerprints

• During a criminal investigation, those are the sequences that are studied using restriction enzymes, PCR and gel electrophoresis

• Gel electrophoresis-isolation of DNA using electrical currents and a gel matrix made of sugars

Page 10: Genetic Engineering and Recombinant DNA Technology

Genetic Fingerprinting: Gel Electrophoresis

DNA has (-) charge, it will run towards the bottom of gel that has (+) charge

Fragments separate based on size. Match fragment pattern with DNA found at scene.

Take DNA found at crime scene

Restriction enzymes, STRs, PCR

Gel electrophoresis Compare DNA fragmentsname suspect

Page 11: Genetic Engineering and Recombinant DNA Technology

DNA Sequencing

• Allows for the actual nucleotide sequence to be known• Automated, done by machines• Used to “solve” all the genes in humans Human Genome Project• Is there an advantage to knowing the entire gene sequence of an organism?• Functional genomics and comparative genomics

Page 12: Genetic Engineering and Recombinant DNA Technology

Applications of Genetic Engineering

• In agriculture:• Strawberries that resist frost• rice with beta carotene• tomatoes that last longer• pest resistant corn (95% modified)• Larger animals more meat, milk• In environment:• Bacteria that clean up oil/toxic spills• In medicine:• Insulin, growth hormone, interferon,

taxol, relaxin, erythropoietin

Page 13: Genetic Engineering and Recombinant DNA Technology

Genetic EngineeringProblems:• Is it safe for human consumption? Allergies?• If organisms get out into natural setting,

impact environmental balance? • Bigger animalsmore waste, competition• Hybrids: herbicide resistance gene in corn

passed to a weedThe “Enviropig” has been genetically modified in such a manner that its urine and feces contain almost 65 percent less phosphorus than usual.

Page 14: Genetic Engineering and Recombinant DNA Technology

Gene Therapy

Introducing the normal gene into humans with disease

We can make the genes through rDNA, but how do we get them inside to every cell?

Ex vivo gene therapy uses modified viruses to get the new gene inside cells SCID, familial hypercholesterolemia

In vivo gene therapy uses direct injection or inhalation of normal/healthy gene to defective cells/organs

How do we prevent an immune reaction?