End Show Slide 1 of 32 Copyright Pearson Prentice Hall Manipulating DNA

End Show 13-2 Manipulating DNA Slide 2 of 32 Copyright Pearson Prentice Hall Scientists use knowledge of the structure and function of DNA to manipulate it. The Tools of Molecular Biology

End Show 13-2 Manipulating DNA Slide 3 of 32 Copyright Pearson Prentice Hall The Tools of Molecular Biology Techniques: extract DNA from cells cut it into smaller pieces identify the sequence of bases in it make unlimited copies of it

End Show 13-2 Manipulating DNA Slide 4 of 32 Copyright Pearson Prentice Hall The Tools of Molecular Biology DNA Extraction The cells are broken open and the DNA is separated from the other molecules.

End Show 13-2 Manipulating DNA Slide 5 of 32 Copyright Pearson Prentice Hall The Tools of Molecular Biology Cutting DNA DNA is cut into smaller fragments using restriction enzymes.

End Show 13-2 Manipulating DNA Slide 6 of 32 Copyright Pearson Prentice Hall The Tools of Molecular Biology Each restriction enzyme cuts DNA at a specific sequence of nucleotides. Recognition sequences DNA sequence Restriction enzyme EcoR I cuts the DNA into fragments Sticky end

End Show 13-2 Manipulating DNA Slide 7 of 32 Copyright Pearson Prentice Hall The Tools of Molecular Biology Separating DNA - gel electrophoresis DNA fragments are placed at one end of a porous gel and an electric voltage is applied. The negatively-charged DNA molecules move toward the positive end of the gel.

End Show 13-2 Manipulating DNA Slide 8 of 32 Copyright Pearson Prentice Hall The Tools of Molecular Biology DNA plus restriction enzyme Mixture of DNA fragments Gel Power source Gel Electrophoresis Longer fragments Shorter fragments

End Show 13-2 Manipulating DNA Slide 9 of 32 Copyright Pearson Prentice Hall The Tools of Molecular Biology First, restriction enzymes cut DNA into fragments. The DNA fragments are poured into wells on a gel. DNA plus restriction enzyme Mixture of DNA fragments Gel Gel Electrophoresis

End Show 13-2 Manipulating DNA Slide 10 of 32 Copyright Pearson Prentice Hall The Tools of Molecular Biology An electric voltage is applied to the gel. DNA fragments move across the gel. Smaller fragments move faster and farther. Power source Gel Electrophoresis

End Show 13-2 Manipulating DNA Slide 11 of 32 Copyright Pearson Prentice Hall The Tools of Molecular Biology DNA fragments make a pattern of bands. These bands can then be compared with other samples of DNA. Longer fragments Shorter fragments Gel Electrophoresis

End Show 13-2 Manipulating DNA Slide 12 of 32 Copyright Pearson Prentice Hall Using the DNA Sequence Cutting and Pasting Enzymes that splice DNA together make it possible to take a gene from one organism and attach it to the DNA of another. Such DNA molecules are called Recombinant DNA.

End Show 13-2 Manipulating DNA Slide 13 of 32 Copyright Pearson Prentice Hall Using the DNA Sequence Making Copies Polymerase chain reaction (PCR) allows biologists to make copies of genes. -DNA is heated to separate its two strands. -Primers bind to the single-stranded DNA. -DNA polymerase makes copies of the DNA

End Show 13-2 Manipulating DNA Slide 14 of 32 Copyright Pearson Prentice Hall Using the DNA Sequence DNA heated to separate strands PCR cycles DNA copies etc etc. Polymerase Chain Reaction (PCR) DNA polymerase adds complementary strand DNA fragment to be copied

End Show 13-2 Manipulating DNA Slide 15 of 32 Copyright Pearson Prentice Hall Cell Transformation Recombinant DNA Host Cell DNA Target gene Modified Host Cell DNA

End Show 13-2 Manipulating DNA Slide 16 of 32 Copyright Pearson Prentice Hall Transforming Bacteria A cell takes in DNA from outside the cell. Foreign DNA is first joined to a small, circular DNA molecule in bacteria known as a plasmid.

End Show 13-2 Manipulating DNA Slide 17 of 32 Copyright Pearson Prentice Hall Transforming Bacteria Recombinant DNA Gene for human growth hormone Human Cell Bacteria cell Bacterial chromosome Plasmid Sticky ends DNA recombination Bacteria cell containing gene for human growth hormone DNA insertion

End Show 13-2 Manipulating DNA Slide 18 of 32 Copyright Pearson Prentice Hall Transforming Plant Cells A bacterium exists that produces tumors in plants. Researchers can inactivate the tumor gene and insert a piece of foreign DNA into the plasmid. The recombinant plasmid can then be used to infect plant cells.

End Show 13-2 Manipulating DNA Slide 19 of 32 Copyright Pearson Prentice Hall Transforming Plant Cells Complete plant generated from transformed cell. Inside plant cell, Agrobacterium inserts part of its DNA into host cell chromosome. Plant cell colonies Transformed bacteria introduce plasmids into plant cells. Agrobacterium tumefaciens Cellular DNA Gene to be transferred Recombinant plasmid

End Show 13-2 Manipulating DNA Slide 20 of 32 Copyright Pearson Prentice Hall Transforming Animal Cells DNA can be directly injected into the nucleus of an egg cell. Enzymes insert the foreign DNA into the chromosomes of the injected cell.

End Show 13-2 Manipulating DNA Slide 21 of 32 Copyright Pearson Prentice Hall Transforming Animal Cells Recombinant DNA Modified Host Cell DNA Target gene Flanking sequences match host Recombinant DNA replaces target gene

End Show 13-2 Manipulating DNA Slide 22 of 32 Copyright Pearson Prentice Hall Applications of Biotechnology Transgenic Organisms Contains genes from other species.

End Show 13-2 Manipulating DNA Slide 23 of 32 Copyright Pearson Prentice Hall Transgenic Organisms Transgenic Microorganisms Transgenic bacteria produce important substances useful for health and industry. insulin growth hormone clotting factor

End Show 13-2 Manipulating DNA Slide 24 of 32 Copyright Pearson Prentice Hall Transgenic Organisms Transgenic Animals Transgenic animals have been used to improve the food supply. Mice have been produced with human genes that make their immune systems act similarly to ours. This allows scientists to study the effects of diseases on the human immune system.

End Show 13-2 Manipulating DNA Slide 25 of 32 Copyright Pearson Prentice Hall Transgenic Organisms Transgenic Plants Transgenic plants are now an important part of our food supply. Many of these plants contain a gene that produces a natural insecticide, so plants don’t have to be sprayed with pesticides.

End Show 13-2 Manipulating DNA Slide 26 of 32 Copyright Pearson Prentice Hall Cloning A clone is a member of a population of genetically identical cells produced from a single cell. In 1997, Ian Wilmut cloned a sheep called Dolly. Dolly and Bonnie

End Show 13-2 Manipulating DNA Slide 27 of 32 Copyright Pearson Prentice Hall Cloning Cloning Dolly Donor Nucleus Fused cell Embryo Egg Cell Foster Mother Cloned Lamb

End Show 13-2 Manipulating DNA Slide 28 of 32 Copyright Pearson Prentice Hall Cloning Cloning Dolly

End Show 13-2 Manipulating DNA Slide 29 of 32 Copyright Pearson Prentice Hall Cloning Cloning Dolly

End Show 13-2 Manipulating DNA Slide 30 of 32 Copyright Pearson Prentice Hall Cloning Cloning Dolly

End Show 13-2 Manipulating DNA Slide 31 of 32 Copyright Pearson Prentice Hall Cloning Cloning Dolly

End Show 13-2 Manipulating DNA Slide 32 of 32 Copyright Pearson Prentice Hall Cloning Cloning Dolly

End Show 13-2 Manipulating DNA Slide 33 of 32 Copyright Pearson Prentice Hall Cloning Cloning Dolly