Gene Technology

1. Gene Technology Genetic Engineering Human Application Agriculture Application

2. Quick Review Describe the structure of DNA. • Nucleotides linked end to end in two strands twisted in a double helix. • Nucleotides contain a phosphate group, a sugar molecule, and one of the four bases.

3. What are the base pairing Rules in DNA? • Adenine pairs with Thymine • Guanine pairs with Cytosine Why is the genetic code said to be universal? • It is nearly the same in every living thing

4. Genetic Engineering • The process of altering the genetic makeup of an organism. • Involves Recombinant DNA – DNA made from two or more different organisms by connecting or reconnecting DNA. • “Recombine” • Achieved by the use of vectors- an agent that is used to carry the gene of interest into another cell. • Viruses, yeast, and plasmids

5. Plasmid- circular DNA molecules that can replicate independently of the main chromosomes of bacteria.

6. 4 Basic Steps to Genetic Engineering • Step 1 Cutting the DNA • Restriction enzymes- bacterial enzymes that recognize and bind to specific short sequences of DNA. • They act like scissors by cutting the DNA between specific nucleotides within the DNA sequence.

7. Step 2 Combining DNA fragments of gene of interest and the DNA fragment from the vector. Uses an enzyme called Ligase. Acts like glue or tape. Step 3 Cloning- many copies of the gene of interest are made each time the host cell reproduces. Step 4 Screening- method used to detect which bacteria have the vector and which ones do not.

11. Confirmation of a Cloned Gene • Southern Blot • Electrophoresis- technique that uses an electric filed within a gel to separate molecules by their size. • Probe- radioactive or fluorescent RNA or DNA strands that can bind to gene of interest.

12. Electrophoresis Process

13. Gel Electrophoresis

14. Human Applications of Genetic Engineering The Human Genome Project • The Human Genome Project is a research project started in 1990 to identify all the base pairs of the human genome. • Genome = all the genes in the DNA of a species. • In 2003, 13 years later, the genome was published.

15. The Genome project provided some surprising findings: • Less than 2% of human DNA codes for proteins. • The human genome contains fewer than 40,000 genes, considerable less than the 120,000 different types of mRNA molecules.

16. Gene Technology Genetic Engineering Human Application Agriculture Application

17. The Human Genome project has led to certain benefits: • Identification of markers for genetic disorders that help determine individuals that are carriers. • Advances in developing gene therapy. • Better vaccines

18. Genetically engineered Drugs and Vaccines • Many genetic disorders result when the body’s cells do not produce critical proteins. • Genetically engineered proteins are used to treat these conditions. • Insulin for type 1 diabetes • Factor VIII, a blood clotting factor used to treat one type of hemophilia. • Interferon for viral infections and cancer.

19. VaccinesTraditional Method • Vaccine- solution containing all or part of a harmless version of a pathogen (disease causing microorganism) • Vaccines cause the bodies immune system to produce antibodies. • Should that particular pathogen enter the body, the antibodies will attack and kill it.

20. The traditional method of vaccine preparation has the danger that the pathogen may not be fully disabled and may cause the disease anyway. • Genetically Engineered Drugs/ Vaccines • Using genetic engineering the genes that encode the surface proteins of the pathogen can be inserted into the DNA of a harmless virus. • Vaccines for Herpes II (genital) and hepatitis B are now being made through genetic engineering.

21. DNA Fingerprinting • No two individuals have the same DNA, except identical twins, so DNA technology can be used to identify individuals and relationships.

22. DNA Fingerprint Process 1. DNA is cut with restriction enzymes. Because the places restriction enzymes can cut DNA depend on the DNA sequence, the lengths of DNA restriction fragments will differ between two individuals. 2. Electrophoresis is run

23. DNA Fingerprint

24. Using samples of DNA from blood,semen, bone, or hair forensic investigators can identify a suspect or victim in criminal investigations. • It can also be used to identify genes that cause genetic disorders.

25. Genetic Engineering in Agriculture Genetic engineering techniques have been used to produce crop plants that are: – Tolerant of drought conditions – Resistant to the weed-killer, glyphosate (sold under the trade name Roundup) –Resistant to insects –More nutritious

26. Risks of Genetically Modified Crops –Use of glyphosate resistant crops may lead to resistant weeds. – Plants with genes to improve nutrition may cause allergic reactions in some people. –Genetically engineered crop plants may interbreed with wild plants.

27. Gene Technology in Animal Farming • Genetically engineered bacteria are producing animal hormones that stimulate growth and increase milk production. • Human genes have been added to the genes of farm animals to get them to produce medically useful proteins in their milk. • Such animals are called transgenic. • Transgenic = organisms that have DNA from another species

29. CLONING FROM ADULT ANIMALS• In 1997, Ian Wilmut, announcedthe first successful cloning of anadult animal using a cell takenfrom the mammary gland of anadult—the cloned sheep, Dolly.

30. PROBLEMS WITH CLONING • Since the successful cloning of Dolly, many other animals have been cloned. However, only a few survive for long • The problem lies in a process called genomic imprinting –Occurs during the development of sperm and egg cells. – Insures that the right combination of genes is turned “on” or “off” during early development