Genetic Engineering

Genetic Engineering: The process of manipulating genes for practical purposes. ** Involves Recombinant DNA: DNA made from two or more different organisms. EX. Human gene for insulin is inserted into bacteria. Because the genetic code in universal, the human gene can be transcribed and translated by bacteria.

Steps in Genetic Engineering: 1.Cutting the Desired DNA: Both the DNA from the organism containing the gene of interest (ex. Insulin gene) and the DNA from a vector are cut. 2.The DNA is cut using restriction enzymes which act as scissors for a specific piece of DNA. Vector: An agent that carries the DNA into cells. Ex. Virus, yeast, plasmid ( circular pieces of DNA that can replicate independently of the main chromosome of bacteria.) Gene of interest Antibiotic resistance gene Plasmid vector Recombinant DNA

3.Recombinant DNA is produced: DNA which contains the new gene. The DNA fragments are combined and the host cells (usually bacteria) take up the DNA. This process is called transformation. 4. Cloning: Many copies of the DNA are made when the bacteria reproduce by binary fission 5. Screening: Cells that have taken up the DNA of interest are distinguished from those that did not take up the DNA New DNA will be copied

Bt gene: A bacterial gene produces a protein which is toxic to harmful insects. It has been put into corn, cotton and other plants so that insecticides do not have to be used. Bt gene is removed using restriction enzymes Bt gene inserted into corn

Transgenic Animals A transgenic animal is one that carries a foreign gene that has been deliberately inserted into its genome. The foreign gene is constructed using recombinant DNA technology. In addition to a structural gene, the DNA usually includes other sequences to enable it to be incorporated into the DNA of the host and to be expressed correctly by the cells of the host.

GENETIC ENGINEERING (MIXING GENES FROM TWO DIFFERENT SPECIES) JELLYFISH RICEFISH +

=EQUALS GLOWING RICEFISH

Sounds like a good idea??? Their fluorescence is actually a hindrance in the wild, requiring energy to maintain and making them more susceptible to predators (who wouldn’t be harmed by eating the fish-- GFP is completely non-toxic).

Selective breeding: Allowing only those organisms with desired traits to mate and produce offspring. Ex. Used frequently in dog breeding. This is NOT genetic engineering !

Example of selective breeding: Pigs are selectively bred for a lower genetic ability to produce fat.

Biological Controls: Using organisms to control environmental problems so that harmful chemicals do not have to be used. EX. Using ladybugs to eat nasty little aphids that eat your plants or using oil digesting bacteria to clean up oil spills. An alternative to genetic engineering and harmful pesticides

Gel electrophoresis: a method that separates molecules on the basis of size, electric charge, and other physical properties. During electrophoresis, molecules are forced to move through the pores when the electrical current is applied. Their rate of migration through the electric field depends on the strength of the field, size and shape of the molecules, relative hydrophobicity of the samples, and on the ionic strength and temperature of the buffer in which the molecules are moving. After staining, the separated macromolecules in each lane can be seen in a series of bands spread from one end of the gel to the other.

An individual's DNA is as distinctive as a fingerprint. This technique was used to assist in determining O.J. Simpson's life. DNA samples can be obtained from the trace amounts of blood or semen. These DNA samples can be separated using gel electrophoresis. The number and position of bands formed on each lane of gel is the actual genetic "fingerprint" of that DNA sample. The characteristics of certain segments of DNA vary from person to person and form a highly individual, detectable "genetic fingerprint." Developed only in the mid-1980s, genetic fingerprinting has rapidly become a widely used courtroom tool. In 1988 the first person in the United States was executed based on DNA technology.

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