gene technology. i. genetic engineering a.basic steps of genetic engineering manipulation 1. genetic...
TRANSCRIPT
Gene Technology
I. Genetic Engineering
A. Basic Steps of Genetic Engineering
1. Genetic Engineering – Manipulation of DNA for practical purposes
2. Restriction enzymes – 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
“sticky”ends.
b. Sticky ends allow DNA fragments from different
organisms to join together to form recombinant
DNA.
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.
B. Confirmation of a Cloned Gene
1. Gel Electrophoresis – uses an electric field within a gel to separate DNA fragments by their size.
2. Specific genes can be indentified with DNA or RNA probes using the Southern Blot technique
Gel Electrophoresis
C. DNA fingerprinting
1. A DNA fingerprint is a restriction fragment electrophoretic pattern made from biological samples.
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.
II. Human Applications of Genetic EngineeringA. The Human Genome Project
1. An effort to determine the nucleotide sequence and map the contents of every gene on each human chromosome.
2. Large amounts of DNA do not 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
Genetically Engineered
Human Insulin
III. Genetic Engineering in Agriculture
A. Improving Crops
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 unforseen negative 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 introduced into foreign organisms
Genetically modified strawberry 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.
C. Gene Technology in Animal Farming
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
their cells.
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
D. Cloning from Adult Animal cells
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 not been 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.
Scotland's Dolly the sheep was the world's first cloned mammal.
Left - Cell DonorMiddle - Cloned DogRight - Surrogate MotherDolly
CC Rhesus monkey
The End