Genetic Engineering

Vocabulary Gene – sequence of DNA that codes for a trait (protein). Genome – an organism’s complete genetic information. Transgenic organism – an organism that carries a foreign gene in its genome that is from a different organism. Recombinant DNA – DNA from two or more sources that have been combined.

Transgenic Bacteria Also known as GMOs (genetically modified organisms). Most transgenic bacteria reproduce every 22 minutes. Produce a host of important substances such as insulin, growth hormone, and blood clotting factor.

Transgenic Plants Chances are you had some for dinner last night. Some species are capable of producing own insecticides. Some GM plants produce human proteins and antibodies to fight disease.

Transgenic Animals Have been developed to study genes in order to improve the food industry. Transgenic livestock have extra copies of growth hormone to grow faster and leaner meats.

Transgenic Insects Scientists at UMBI- CARB in Rockville, MD are developing a transgenic mosquito that is resistant to malaria. Malaria is a disease caused by a parasite that is transmitted to humans by mosquito.. This GM mosquito carries a gene that confers resistance to the malaria parasite. Scientists know that the mosquito carries this gene as the insect's eyes turn fluorescent green (Image: PNAS)

Cell Transformation Also known as gene splicing or gene cloning. Bacterial transformations began in 1977 with a company called Genentech. Herbert Boyer utilized bacteria called Escherichia coli (E.coli) to mass produce human insulin.

Cell Transformation Most DNA plasmids contain genetic markers such as an antibiotic resistance and/or bioluminescent genes. AMP r – ampicillin resistance gene pGreen – plasmid containing green fluorescent gene These genetic markers express proteins to help scientists locate the one cell in a million that has been transformed.

MICROINJECTION TRANSFORMATION Another technique to introduce foreign DNA into a host organism is by microinjection. This has helped develop insects to become resistance to parasites that can cause human diseases such as malaria or sleeping sickness.

Suction device to hold embryo Embryo Microinjection needle MICROINJECTION TRANSFORMATION

SELECTIVE BREEDING Producing genetic variation by using NATURAL genetic variations to pass desired traits to the next generation. Results in new plant varieties, new animal breeds A subdivision of a species. Labradoodle

SELECTIVE BREEDING HYBRIDIZATION- uses very different plants to produce hybrids with desired traits INBREEDING- uses very similar animals to keep the desired traits

Genetic Engineering Tool Kit Plasmids are special circular DNA molecules. Plasmids are freely exchanged by bacteria in the environment. Plasmids can be engineered in a lab to carry any gene.

RESTRICTION ENZYMES - molecular scissors

Restriction Enzymes Restriction enzymes (RE) are isolated from bacteria. They are named from the organism from which it was isolated. EcoR1 E – genus name, Escherichia co – species, coli R - strain 1 - number Cut only at a very specific sequence of DNA nucleotide bases and leave sticky ends.

Manipulating DNA Genes are sequences of DNA that code for a protein or trait. They are very similar in humans. Some DNA does not code. This non-coding DNA forms stable, repeating sequences that are different lengths from person to person. Restriction enzymes recognize specific sites and can cut these repeating sequences into fragments that vary in length. These pieces of different lengths are called RFLP- restriction fragment length polymorphisms This makes different numbers and different sized pieces for every individual human- a one-of-a-kind DNA fingerprint

GEL ELECTROPHORESIS DNA fragments are loaded into an agarose gel and separated by size using an electrical current. The fragments travel in a specific direction based on their surface charge. DNA IS NEGATIVE. They travel at different speeds based on their size- SMALLER PIECES TRAVEL FASTER. DNA fragments are measured in numbers of base pairs.

DNA Fingerprinting VISUALIZATION- the gel is stained with methylene blue- the DNA bands stain darker than the background gel DNA fingerprint banding patterns are utilized for medical research or forensic science.

In 1977 British scientist Alec Jeffreys developed the DNA fingerprinting technique. In 1984, DNA fingerprinting was first used to solve a paternity and murder case.