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Manipulating DNA. Selective Breeding. Man has selectively bred plants and animals for desired traits. Mutations of Pointsettias induced by radiation. New DNA Technology. Now DNA can be manipulated to produce new combinations not found in nature How far should we go?
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Selective Breeding • Man has selectively bred plants and animals for desired traits
New DNA Technology • Now DNA can be manipulated to produce new combinations not found in nature • How far should we go? • We need to set bioethical limits
Restriction Fragment Length Polymorphism(RFLP) Analysis • DNA is cut into small pieces using restriction enzymes • Many copies are made using PCR • Radioactive probes attached to mark ends • An electric current is used to separate pieces by size in a gel • Larger pieces are slower and don’t move as far down the gel http://www.sumanasinc.com/webcontent/animations/content/gelelectrophoresis.html
DNA Fingerprinting • DNA is unique for every individual • Comparing the sequences of small pieces of DNA can be used: • Find relationships • Narrow crime suspects • Identify organisms
Restriction enzymes Cuts the desired DNA strands Bacterial plasmid cloning vector used to move DNA to another organism Host DNA Donor gene(s) Produces a transgenic organism with recombinant DNA Tools needed in Gene Cloning
Clones • Copies of one organism
Clones • Produced by taking cuttings from one plant • Grafting • Budding • Rooted cuttings
Clones • Produced for many years by dividing an embryo to form identical quadruplets • Cows • Pigs
A New Type of Clone • The nucleus of a donor cell • The ova (egg) of another organism • A surrogate mother
Food producers, including Tyson Foods Inc. and Dean Foods Co., said they won't use cloned foods anytime soon. Bloomberg News / January 16, 2008 WASHINGTON - Cloned cows, pigs, goats, and their offspring are safe to enter the US food supply, regulators said over protests from lawmakers, consumer groups, and worried eaters. FDA says cloned animals safe to eat
Controversial topics… • Scientists hope to use cloned embryos to harvest precious "stem cells" — cells that, in theory, can ultimately grow into any kind of cell in the body. • These cells could be used to generate new organs or cell clusters to treat patients with failing organs or degenerative diseases • In the case of transplant patients, organs made from exact copies of an individual's own cells and would not be rejected. • This research is still in its earliest phase of development. All of the embryos generated actually died — none grew beyond the six-cell stage • Controversial: The thinking is that by allowing any kind of cloning of human embryos, it is then not such an enormous leap to apply the same techniques to making copies of people.
Some problems to Overcome: • Many casualties • Birth defects • Failures • Premature aging • Improve technique