1. Bellwork: What kinds of crimes can be solved using DNA evidence? Why?

2. Applications of Genetic Engineering
Section 15.3

3. In today’s class we will…
Looks at uses of genetic engineering for:
Transgenic crops
Transgenic animals
Medicine and health
Gene therapy
Look at how our understanding of how genes are regulated has developed
How DNA can be used to identify individuals
To solve crimes
Identify paternal relationships

4. How does genetic engineering benefit agriculture and industry?
Life as we know it depends on living organisms
What we eat
What we wear
Researchers have attempted to use genetic engineering to improve the products we get from plants and animals
Overall goal is to produce better, less expensive and more nutritious food, and a less harmful manufacturing process

5. Genetically modified crops
First introduced in 1996
In 2007 they made up 97 % of soybeans, 86 % of cotton and 80 % of corn in the US.
Possibility of programming into plants a natural insecticide effect
If plants have Bt gene to produce BT toxin, enzymes in insects convert Bt toxin to a lethal form, killing the insect
Also possible to ’program’ into plants a natural herbicide resistance
Increase farmers yield
Can program resistance to viral infections
Future possibilities include a resistance to rot and spoilage

6. Potential issues with GM crop usage
In the USA, herbicide resistance has lead to an increased use of herbicides
Herbicides are dangerous chemicals
Potentially dangerous to humans
Continued exposure could cause dangerous diseases such as cancer

7. GM crops usages in the united states

8. Genetically modified animals
Transgenic animals are also becoming important to our food supply
30% of milk in US comes from cows that have been injected with hormones made by recombinant DNA techniques to increase milk production
Transgenic salmon has been produced using growth hormones, which grows much faster than wild salmon
Spider genes have been combined into cells of lactating goats
Goat produces silk along with milk
Sales of meat and milk from cloned animals has been legal in the US since 2008
You may have eaten cloned meat without realizing!
Impossible to tell the difference (although cloned animals are normally only cloned for breeding stock)

9. How does recombinant DNA technology improve human health?
Preventing Disease
Food can be genetically modified to contain essential nutrients
Example Golden Rice (See articles)
Defficiancies in ProVitamin A can lead to infant bkindess
Potential for transgenic plants and animals that produce human antibodies to fight disease
Medical Research
Transgenic animals can be used to simulate human disease where defective genes play a role
Treating disease
Using recombinant DNA in bacteria we can make proteins that were previously hard to make (Human growth hormone)

10. Gene therapy
Can we simply replace a defective gene with a new improved version?
New field of medicine call gene therapy is attempting to do this
Possible due to advances in molecular biology and the human genome project
Scientists genetically engineer viruses so that it can’t reproduce or cause harm
DNA containing the modified gene is implanted into the virus
Patient’s cells are infected with the virus
In theory defective gene is replaced, but still experimental procedure

11. Genetic testing
It is possible for potential parents to find out if they are carriers for genetic diseases such as cystic fibrosis
Hundreds of genetic disorders can be identified
Specific DNA sequences that detect the complementary base sequences are used to identify the gene causing alleles

12. Examining active genes
Genes in the human body are not always active
Explains how cells function normally, and what happens when cells don’t work properly
Scientists use a DNA microarray technology to study hundreds or thousands of genes at once
This is a glass slide or silicon chip that to which spots of single stranded DNA are tightly attached
If you want to compare genes from cancer cell to genes from normal cells in the same tissue, mRNA is extracted from both cell types and copied into single stranded DNA with a fluorescent color.
These cells compete for binding sites on the slab
Slab is scanned to see whether cancer cells or normal cells produce more of a particular kind of mRNA – you can visually see which has bound more to the spot for a gene
YouTube video DNA microarrays…..

13. How do we use DNA to identify individuals?
Remember, every individual has a unique genome
Except for identical twins
This idea is the basis for DNA fingerprinting
Sections of DNA that widely vary from one individual to another, bit have little or no function are analyzed
Gaps between genes

14. How is the fingerprint produced?

15. Forensic Science DNA fingerprinting has been used since the 1980s
Revolutionized Forensics
Used to solve crimes, convict criminals, even overturn wrongful convictions
DNA has overturned over 110 wrongfully convicted death row prisoners
Also used to target ivory trade
Investigators can identify which herd ivory came from on the basis of DNA

16. Establishing family relationships
DNA fingerprinting makes it possible to identify alleles carried by the child that are not carried by mother
Any others must come from the father
They will be present in his DNA fingerprint
It is % effective
Determining ancestry can be a bit hard, due to the genetic scrambling during Meiosis and sexual reproduction
We do have some clues..
Y chromosome always passes father to son
Mitchondrial DNA always passes mother to child

17. Summary
Genetic engineering is a very useful aspect of Moelcular Biology
Transgenic plants and animals can have numerous benefits to society
Recombinant DNA can be used to create medicines
Gene therapy is a new exciting field with a lot of potential for treating genetic diseases
Our understanding of how genes are activated is ongoing using DNA microarrays
Finally, DNA can be used to trace individuals
Solving crimes
Identifying paternity