Gene Technology. I. Genetic Engineering. Basic Steps of Genetic Engineering 1. Genetic Engineering – Manipulation of DNA for practical purposes 2. Restriction e nzymes – enzymes that cut DNA into fragments that have short sticky ends. 3. Steps in a Genetic Engineering Experiment
1. Genetic Engineering – Manipulation of DNA for practical purposes
2. Restrictionenzymes – enzymes that cut DNA into fragments that have short sticky ends.
3. Steps in a Genetic Engineering Experiment
a. Cut DNA (using restriction enzymes)
b. Recombinant DNA is produced
c. The gene is copied
d. Cells are selected and screened for gene of interest
4. Cutting DNA and Making Recombinant DNA
a. Restriction enzymes are used to generate
b. Sticky ends allow DNA fragments from different
organisms to join together to form recombinant
5. Cloning, Selecting and Screening Cells
a. Recombinant DNA is inserted into host cells.
b. Each time the cells reproduce, the gene of
interest is copied.
c. The cells are then screened to indentify cells that
have the recombinant DNA.
1. Gel Electrophoresis – uses anelectricfield within a gel to separate DNA fragments by their size.
2. Specific genes can be indentified with DNA or RNA probes using the SouthernBlot technique
1. A DNA fingerprint is a restriction fragment electrophoreticpattern made from biologicalsamples.
a. DNA is extracted and cut into segments using restriction enzymes and are separated by electrophoresis.
b. The segments are radioactively tagged to produce a visual pattern known as a radiograph or “DNA fingerprint” on X-ray film
2. DNA fingerprints are used to identify suspects at a crime scene, paternity or genetic disorders.
3. It depends on the fact that no two people, except identical twins, have exactly the same DNA sequence.
1. An effort to determine the nucleotide sequence and map the contents of every gene on each human chromosome.
2. Large amounts of DNA donot encode for proteins
3. Human cells contain about 30,000 to 40,000 genes
B. Genetically Engineered Drugs and Vaccines
1. Genetic engineering is used to manufacture human proteins for use as drugs.
2. Genetic engineering is used to manufacture virus components for making safer and more effective vaccines
1. Plants can be genetically engineered to have desirable characteristics; including increased yields and resistance to herbicides and destructive pests
2. Plants can also be designed to have improved nutrition value; such as rice enriched with iron and vitamin A.
B. Risks of Genetically Modified Crops
1. There may be unforseennegative effects of using genetically modified crops that are immune to herbicides and there may be a possibility of causing allergies.
2. There may be a possibility of GM genes being introducedinto foreign organisms
A gene was added which causes it to be blue.
Pizzamatoes – tomatoes which have been genetically modified to exhibit characteristics of basil, garlic and oregano.
1. Genetically engineered growth hormone can increase milk production in dairy cows and weight in cattle and hogs.
2. Transgenic animals have foreign DNA introduced to
a. Human genes could be introduced into farm animals
which could produce human proteins in their milk
b. Genes from spiders have been introduced into goats
who produce milk which has spider silk proteins
1. Cloning of farm animals from adult cells was first accomplished in 1997 when Dolly, a sheep, was born to a surrogate mother.
2. Various other animals have since been cloned; cats, cattle, dogs, goats, horses, and rhesus monkeys
3. Cloning has notbeen perfected. There are problems which are due to the fact that genetic imprinting (preparation) occurs in the sperm and egg cells prior to fertilization. Cloned cells do not undergo this process and many cloned animals have developmental problems.
Middle - Cloned Dog
Right - Surrogate Mother
Scotland's Dolly the sheep was
the world's first cloned mammal.