Genetic Engineering

Genetic Engineering- manipulating genes for practical purposes –Many medicines, such as the ones used to treat burns, are produced by genetic engineering techniques. –A person vaccinated with a genetically engineered vaccine, such as the genital herpes vaccine, will make antibodies against the virus. These antibodies will multiply in the person’s body, and will fight off the herpes virus if exposed. The long range goal of genetic engineering is to correct genetic defects by transferring normal genes to cells that lack them (“gene therapy”).

Genetic engineering can also be used in agriculture. Genetically modified crops may be both beneficial and harmful Positive Effects: –Taste better –Grow faster –More nutritious –Resistant to insects/herbicides –Solve food shortages in developing countries Negative Effects: –Antibiotic resistance –New allergies –Negative effects on ecosystem –Economic impact on other farmers and pesticide manufacturers Lettuce engineered to have longer shelf life

Steps in Genetic Engineering Gene Splicing- method of cutting the DNA using enzymes –Once the DNA is cut, it is inserted into a host cell, typically a bacterium. This host cell will reproduce, and each time it does, all of the genetic material will be copied, including the original DNA. –Recombinant DNA- DNA made from two or more different organisms

Producing Recombinant Organisms

DNA Fingerprinting DNA Fingerprinting – method of genetic identification based on unique DNA sequences ◦ Procedure:  Small DNA sample cut with restriction enzymes  DNA fragments separated by size using gel electrophoresis  DNA is negatively charged  Series of bands of DNA of various sizes results in a pattern, which is compared to other patterns  Small fragments travel farther toward positive pole

DNA Fingerprinting - Gel Electrophoresis DNA plus restriction enzyme Mixture of DNA fragments Power source Gel Heavier, Longer fragments Shorter, lighter fragments

Cloning Cloning- producing an organism by asexual reproduction that is genetically identical to the original organism Clone- group of organisms that have exactly the same genes –Organisms that reproduce asexually produce clones. Most work done on cloning has been done on frogs. –Replace haploid nucleus of an egg cell with a diploid nucleus from a body cell

Cloning A donor cell is taken from a sheep’s udder. These two cells are fused using an electric shock. The nucleus of the egg cell is removed. The fused cell begins dividing normally. Somatic Cell Donor Egg Cell Donor Surrogate Mother Cloned Organism