Chapter 15: Genetic Engineering

1. Chapter 15: Genetic Engineering Section 15-3: Applications of Genetic Engineering

2. Agriculture and Industry • Genetic engineering used to improve products we get from plants and animals • Could lead to better, less expensive, more nutritious food, and safer manufacturing processes

3. GM Crops • Genetically modified plants since 1996 • Example: adding bacterial genes that produce Bt toxin - kills insects • No pesticides needed • Higher crop yields • Resistance to herbicides, viral infections, rot and spoilage • Some being made to produce plastics

5. GM Animals • 30% of milk produced by cows modified with hormones that increase milk production • Pigs that produce leaner meat , high levels of omega-3 • Salmon with extra growth hormone to make them grow quicker • Canada – goats that produce silk • Goat milk with antibacterial enzymes

6. GM Animals • Scientists hoping to clone transgenic animals to increase food supply and save endangered species • 2008 – gov’t allowed sale of meat and milk from cloned animals • Avoid complications of traditional breeding, duplicate exactly

7. Preventing Disease • Making more nutritious plants • Producing antibodies to fight disease • Make proteins we need

8. Medical Research • Transgenic animals used as test subjects • Study defective genes, disease progression • Conduct drug tests

9. Treating Disease • Recombinant DNA technology used to make human proteins to treat disease – human growth hormone, insulin, blood-clotting factor, cancer-fighting proteins • Also gene therapy – the process of changing a gene to treat a medical disease or disorder • Absent or faulty gene replaced with a normal, working gene

11. Treating Disease • Very risky • Need a more reliable way to insert working genes • Make sure it’s not harmful

12. Genetic Testing • Hundreds of diseases/disorders can be tested for • Some use labeled DNA probes that can detect disease-causing alleles • Some search for changes in cutting sequences • Some use PCR to detect differences in length between normal and abnormal alleles

13. Examining Active Genes • Not every gene is active in ever cell all the time • Understand how cells function by studying active genes using DNA microarray technology - measures level of activity of genes

14. DNA Microarray • Glass slide or silicon chip to which spots of single-stranded DNA are attached – each spot with a different DNA fragment • Colored tags label source of DNA

16. DNA Microarray • Red spots = more cancer mRNA • Green spots = more normal mRNA • Yellow spots = both

17. Personal Identification • No 2 individuals are genetically identical (except identical twins) • Regions of chromosomes contain repeated sequences that do not code for proteins that differ from person to person

18. Personal Identification • DNA fingerprinting analyzes sections of DNA that have little/no function but that vary widely from one individual to another • Use REs to cut DNA into fragments, electrophoresis to separate fragments

19. Personal Identification • DNA probe detects fragments with highly variable regions • If enough probe/enzyme combos are used, resulting banding pattern can be used to distinguish a person • DNA from any tissue can be used

20. Forensic Science • Forensics = study of crime scene evidence • Uses DNA fingerprinting to solve crimes, overturn convictions • Wildlife conservation

21. Establishing Relationships • When genes are passed parent to child, the markers used in DNA fingerprinting are scrambled • Y chromosome, however, passed directly from father to son with few changes – paternity tests • Pieces of mitochondrial DNA (mtDNA) also passed from mother to child directly – 2 people with the same mtDNA share a common maternal ancestor