Ch. 13Genetic Engineering DNA Manipulations Applications of Genetic Engineering Cell Transformations

I. Manipulating DNA Some Vocabulary: Polyploidy – many sets (more than 2) of chromosomes Hybridization – breading two organisms with different traits to try and get new or desired traits. Inbreeding – continual breeding of individuals with similar characteristics Selective Breeding – choosing which male and female from a species will mate to try and control the outcome

4 Techniques for Manipulating DNA DNA Extraction – open cells and remove DNA from the rest of the cell Cutting DNA – use Restriction Enzymes to cut DNA at specific sequences into small fragments

4 Techniques for Manipulating DNA Separating DNA – use Gell Electrophoresis to separate DNA by size and charge DNA Fragments are placed at one end of a gel Electric voltage is applied to the gel DNA molecules have a negative charge and move towards the positive end of the gel Smaller fragments move faster and farther.

Gel Electrophoresis

4 Techniques for Manipulating DNA Copy DNA – use Polymerase Chain Reaction (PCR) PCR is a technique that makes many copies of a gene, really fast! Amplifies DNA sequence so its easier to read and copy Why? Study, compare, and find functions of genes Denature – heat the DNA Attach primers – cool DNA and start a DNA sequence Extend/Synthesize – COPY! DNA Polymerase creates new DNA Repeat! – Heat, Cool, Copy

PCR:

DNA Sequencing – to determine the order of the nucleotide bases

DNA Fingerprinting – to determine the order of the nucleotide bases DNA is cut using restriction enzymes and separated on a gel Used in forensic science: crime scenes, paternity cases, blood samples, species identification

Recombinant DNA – combining DNA from different sources DNA can be changed Pieces of “synthetic” DNA can be joined to “natural” DNA using enzymes that splice DNA together (Restriction Enzymes) Take a gene from one organism and attach it to the DNA of another organism

II. Cell Transformation – genetic alteration of cells Plasmids – small circular molecules of DNA placed in bacteria Two important features of manmade plasmids (why it is useful for DNA transfer): DNA sequence is known Has a genetic marker – gene that identifies transformed cell; Example: plasmids resistant to an antibiotic; plasmids carrying human growth hormone

Transforming Bacteria Foreign bacteria is joined to plasmid Some plasmids are taken in by the bacteria = Transformation Treat culture with antibiotic (normally kills bacteria) Transformed bacteria (contain plasmid) will survive Why? They have the gene (marker) for resistance

Transforming Plant Cells Genetically changing plant cells Examples: inactivated plant tumor genes, insect-resistance gene

Transforming Animal Cells Genetically changing animal cells DNA can be injected directly into the nucleus since the cells are so large. Examples: disease resistance, increase milk production in cows, increase muscle size in livestock

III. Application of Genetic Engineering Transgenic Organisms: Genetically Modified Organisms (GMO), contains genes from other organisms Transgenic Microorganisms: reproduce rapidly and easy to grow Bacteria with human genes to make insulin, growth hormone, clotting factors, etc. Transgenic Animals: animals with genes from other organisms Chickens that do not get salmonella Mice with human immune antibodies Animals with leaner meat Pigs/sheep milk with human protein

III. Application of Genetic Engineering Transgenic Plants: plants with genes from other organisms Plants that produce natural insecticides Resistant to Round-Up, bruising, or rotting Plants with human hormones – rice with more vitamin A Cloning: a clone is an organism with genetically identical cells produced from a single cell Mice, sheep, cows, pigs, monkeys Why? Therapeutic proteins in milk, endangered species