1. Code of Life Topic 5 Genetic analyses & Genetic engineering

2. (An incomplete) timeline of genetics 1944 Avery 1952 1958 1968 19531972 1973 1975-77 1983 1990

3. Applications Genetic analyses and engineering

4. Isolating genes Use special proteins to cut the DNA strand at specific places Restriction enzymes: –Target very specific base sequences –Are found in more than 100 different varieties –Are used in nature to protect bacteria from foreign invaders

5. Restriction Enzymes Each restriction enzyme recognizes a very specific nucleotide sequence Example: EcoR1 recognizes GAATTC CTTAAG The enzyme cuts it: GAATTC CTTAAG

7. Which DNA segments are used? Short tandem repeats (STRs) Good for “fingerprinting”

8. Which DNA segments are used? Single nucleotide polymorphisms (SNPs) Catalog of human SNPs Restriction fragment length polymorphisms (RFLPs) are SNPs that change the length of restriction fragments

9. Restriction Fragment Length Polymorphisms (RFLPs)

10. Analyzing the differences between people STEPS 1.Use restriction enzymes to cut the DNA 2.Load the DNA onto agarose gel for gel electrophoresis 3.Analyze the banding pattern

11. Gel Electrophoresis Separates DNA fragments by size using electric current

12. Gel Electrophoresis Larger fragments move more slowly Results in bands of DNA fragments of different lengths

13. DNA Analysis Useful for: –Forensic science (crime scene “fingerprints”) –Determining paternity –Looking at disease risk

14. Lab! We will be conducting a lab to determine whether or not a young woman carries one or two copies of a mutant gene The mutated version of the gene is responsible for Tay Sach’s disease. How do you think we will go about this? –RFLPs and gel electrophoresis Besides the young woman’s, whose DNA should we also look at?

15. To test or not to test? PGD During pregnancy After birth/during childhood As an adult Bioethics

16. Genetic engineering Changing the DNA of organisms

17. Recombinant DNA DNA that is combined from two different organisms. Common/first example: insertion of a gene from an animal into bacteria to harvest protein Important players: –Gene of interest (i.e. insulin, hGH, etc) –Restriction enzymes –Plasmid –Host bacteria

18. Making Recombinant DNA Plasmids - self- replicating rings of DNA containing 2-30 genes, found in bacterial cells Plasmid and gene of interest cut with same restriction enzymes Plasmid and gene have complementary “sticky” ends

20. Making Recombinant DNA 1.Cut the gene of interest using a restriction enzyme 2.Cut the plasmid (using the same enzyme) 3.Insert gene into the plasmid 4.Insert the plasmid into bacteria 5.Grow bacteria and harvest the protein

21. How could you tell if the transformation really took place?

22. Genetic Engineering Applications Pest-resistant crops (Bt toxin)

23. Genetic Engineering Applications Herbicide-resistant crops Fast-growing fish Green-glowing aquarium fish (jellyfish genes) Bacterial drug production (insulin, hGH)

24. Diagram on p. 14 in your packet (for #1-4) Diagram on p. 15 in your packet (for #6-7)