Topic 4.4 Genetic Engineering and Biotechnology Any manipulation of DNA for practical or scientific use is called genetic engineering. DNA fingerprinting Cloning Genetically modified food Gene transfer Paternity ID Biotechnology is used to perform genetic engineering

DNA Profiling (determining a person’s DNA “fingerprint” can be used to determine the parentage of an individual Can be used to link a person to a crime Can be used to determine relationship in a population of organisms, giving data on social interactions, migration patterns and nesting habits. ns/thumb/9/95/Red- billed_quelea_flocking_at_waterhole.jpg/800px -Red-billed_quelea_flocking_at_waterhole.jpg

DNA profiling begins with PCR (polymerase chain reaction) This technique takes a small quantity of DNA and copies it millions of times so it can be analyzed Steps: 1. DNA is heated so H bonds between bases break 2. A primer (single strand of nucleotides) H bonds to specific DNA sequence. 3. DNA polymerase attached DNA nucleotides to makes 2 double strands of that piece of DNA 4. repeat 34 times

Polymerase chain reaction review

Once PCR has amplified the DNA, it can be separated into small distinct sections by gel electrophoresis Steps: 1. Enzymes chop DNA into small pieces 2. The pieces are dyed and put in a well at the end of a gel plate 3. Gel is exposed to an electric current which drags the smallest, most charged molecules the furthest

Gel electrophoresis:

Using PCR and Gel Electrophoresis you can match samples of DNA (make a DNA profile)

Genetic Engineering Techniques: 1.Gene Transfer: adding a gene and/or removing a gene from an organism Because some of all organisms is identical, genes found in one organism can be transferred into another and produce the same instructions. “Fish” Tomatoes Universal DNA

Bt Corn The bacteria Bacillus thuringiensis, produces a protein fatal to many insects. It has been spliced into corn so that the corn produces the protein. Benefits? Higher crop yield less insecticides in the environment Drawbacks? killing more insects than just the pest (bees?) eating the protein

Gene transfer or Gene splicing process: a.Restriction enzyme (called endonuclease) “cuts” the DNA molecule at a specific base pair Sequence. (different enzymes cut at different Sequences)

If both ends of a gene are cut, it can be removed from an organism. If one cut is made a gene can be inserted: b. DNA ligase recognizes “sticky” end of DNA and attaches them. d_fig1.jpg

This technique has been tried in many organisms (including humans) with mixed results (death) It has been most successful using bacteria as the host cell

Once a gene is spliced into a bacteria, the bacteria produces the protein coded by the gene: Insulin endorphins human growth hormone interferon Standard_insulin_syringe.JPG

Gene transfer in transgenic plants: Rice with beta carotene (vitamin A) Plants resistant to herbicides Salt tolerating plants _effect_of_herbicides_zoom.jpg

Plants with “terminator” gene Biopharmaceuticals Antibodies Antigens for human viruses

Gene transfer in transgenic animals: Sheep carrying genes for proteins to treat blood coagulation disease and Cystic fibrosis Genes inserted in Cows to break down prions (Mad Cow disease) and allergin proteins and to resist disease.

Benefits to Genetic modification: 1.GM crops increase food production 2.GM crops use fewer pesticides 3.GMO’s produce medications cheaply 4.More control over crops (produces less variety) 5.Produce crops in countries with poor soil or lack of water.

Harmful effects of Genetic Modification: 1.Genes could be (and already have been – pollen) released into the wild (weeds, decrease in biodiversity) 2.Genes could cross species (has happened in the lab) 3.Crops with pesticides are eaten 4.Risk for allergies and no labeling to avoid them 5.Human food supply in the hands of a few companies

2. Cloning: Producing genetically identical organisms Humans have been cloning plants for thousands of years. grafting Animals for 10 years tbn3.gstatic.com/images?q=tbn:ANd9GcQOHjSX3we7VTMH1jNsXE2zccKFRHNlQ73VIl0qbKCO pY0OpzU

Cloning Process: 1.Nucleus is removed from a somatic cell. 2.Nucleus is removed from an egg cell of another organism. 3.Electricity fuses the nucleus and the egg cell 4.New cell develops invitro 5.Embryo placed in surrogate

Cloning using undifferentiated cells:

Genetic screening (possible because of Human Genome Project) Searches for disabling genes that, for instance, may confer resistance to specific disease To check for certain genes that potentially produce damaging changes in the individuals Early detection may help to avoid its consequence Genetic probes are useful for both prenatal diagnosis and newborn screening to detect rare metabolic disease

Cystic fibrosis, Duchenne muscular dystrophy, hemophilia, Huntington’s disease, neurofibromatosis and brain cancer have been developed tbn1.gstatic.com/images?q=tbn:ANd9GcTycszHofXavKumqdLhLQpjAcm4AwV5ObHTqks5lDjC4 e2NkCB70A henneArms_GeneEditing jpg /diseases/Neurofibromatosis-2.jpg

The Human Race DVD