Chapter 13

1. Biotechnology Chapter 13

2. Biotechnology is applied biology • Modern focus on genetic engineering, recombinant DNA technology, cloning, and analysis of biomolecules • Traditional (historical) applications of biotechnology date back to over 10,000 years ago • Use of yeast to produce beer and wine in Egypt and Near East • Selective breeding of plants and animals Traditional Applications

3. Genetic engineering refers to the modification of genetic material to achieve specific goals Genetic Engineering

4. Major goals of genetic engineering • Learn more about cellular processes, including inheritance and gene expression • Provide better understanding and treatment of diseases, particularly genetic disorders • Generate economic and social benefits through production of valuable biomolecules(vaccines, and hormones) • Improved plants and animals for agriculture Genetic Engineering

5. Genetic engineering utilizes recombinant DNA technology • Splicing together of genes or portions of genes from different organisms • Recombinant DNA can be transferred to plants and animals • Modified animals are called transgenic or genetically modified organisms (GMOs) • Most modern biotechnology includes manipulation of DNA • Many natural processes recombine DNA Recombinant DNA

6. Bacteria can naturally take up DNA from the environment (transformation) and integrate the new genes into the genome (recombination) Transformation

8. Viral life cycle • Viral particle invades host cell • Viral DNA is replicated • Viral protein molecules are synthesized • Offspring viruses are assembled and break out of the host cell Viral Transfer of DNA

10. Forensics is the science of criminal and victim identification • DNA technology has allowed forensic science to identify victims and criminals from trace biological samples • Genetic sequences of any human individual are unique • DNA analysis reveals patterns that identify people with a high degree of accuracy Biotechnology and Forensics

11. Forensic technicians typically have very little DNA with which to perform analyses Polymerase Chain Reaction (PCR) produces virtually unlimited copies of a very small DNA sample Polymerase Chain Reaction

13. Forensic scientists focus on short tandem repeats (STRs) found within the human genome STRs are repeated sequences of DNA within the chromosomes that do not code for proteins STRs vary greatly between different human individuals A match of 13 different STRs between suspect and crime scene DNA virtually proves the suspect was at the crime scene Polymerase Chain Reaction

14. Is a technique used to spread out different-length DNA fragments in a mixture Distinctive pattern of STR numbers and lengths are fairly unique to a specific individual (forming a DNA fingerprint) DNA fingerprint from crime scene can be matched with DNA fingerprint of suspect Gel Electrophoresis

16. At least three-quarters of corn, cotton, and soybeans grown in the US are genetically modified Biotechnology and Agriculture

17. Crop plants are commonly modified to improve insect and herbicide resistance • Herbicide resistant crops withstand applications of weed-killing chemicals • Bt gene (from Bacillus thuringiensis bacterium) can be inserted into plants to produce insect-killing protein in crops Many Crops Are Genetically Modified

18. Modifying a plant genetically begins with gene cloning • Desired gene is first isolated from organism containing it • Desired gene may alternately be synthesized in the laboratory • Gene is next cloned by inserting it into a plasmid which replicates itself autonomously in bacterial cells • Transfect the host organism. Cloning of the Desired Gene

19. Medically useful genes can be inserted into plants—examples: • Potatoes have been engineered to produce harmless hepatitis B virus and E. coli proteins, stimulating an immune response when eaten • Plants could be engineered to produce human antibodies, conferring passive immunity to microbial infection merely by eating the plant GM Plants and Medicines

20. Transgenic (Genetically Modified) animals can be engineered by incorporating genes into chromosomes of a fertilized egg Healthy transgenic animals are difficult to engineer Animals like sheep might be engineered to produce more wool, cattle to produce more proteins in their milk GM Animals

21. Findings • Human genome contains ~25,000 genes • New genes, including many disease-associated genes have been discovered • Has determined the nucleotide sequence of all the DNA in our entire set of genes, called the human genome • The genes comprise 2% of all the DNA The Human Genome Project

22. Applications • Improved diagnosis, treatment and cures of genetic disorders or predispositions • Comparison of our genome to those of other species will clarify the genetic differences that help to make us human The Human Genome Project

23. Potential parents can learn if they are carriers of a heritable disorder through testing Alleles for defective genes differ from normal, functional genes in nucleotide sequence Diagnosis of Inherited Disorders

24. Treatments using DNA technology • Tailored medical care • Recombinant DNA to make proteins • Replacing defective genes to possibly cure a disorder – Gene Therapy • Curing AIDS patients by eliminating the receptor site for the virus • Remove stem cells from red bone marrow, genetically repair the cells, and replace Disease Treatment

25. GM Organisms in Agriculture • The goal of breeding or genetically modifying plants or livestock is to make them more productive, efficient, or useful • Genetic modification differs from selective breeding (“traditional biotechnology”) • Genetic engineering is much more rapid • Genetic engineering can transfer genes between species • Genetic engineering can produce new genes never seen before on Earth Ethical issues of biotechnology

26. Benefits of genetically modified plants • Transgenic crops decrease applications of pesticides, saving fuel, labor, and money • GM plants can be sold at a lower price due to farm savings • Genetically engineered crops can deliver greater amounts of vitamins • e.g. “golden rice” which produces vitamin A GM Organisms in Agriculture

27. Safety issues from eating GMOs • Could ingestion of Bt protein in insect-resistant plants be dangerous to humans? • Are transgenic fish producing extra growth hormone dangerous to eat? Scientific Objections to GMOs

28. Safety issues from eating GMOs • Could GM crops cause allergic reactions? • USDA now monitors GM foods for allergic potential • Toxicology study of GM plants (2003) concluded that ingestion of current transgenic crops pose no significant health dangers Scientific Objections to GMOs

29. Environmental hazards posed by GMOs • Pollen from modified plants can carry GM genes to the wild plant population • Could herbicide resistance genes be transferred to weed species, creating superweeds? • Would they displace other plants in the wild, because they would be less likely to be eaten by insects? Scientific Objections to GMOs

30. Environmental hazards posed by GMOs • Could GM fish reduce biodiversity in the wild population if they escape? • Reduced diversity in wild fish makes them more susceptible to catastrophic disease outbreaks Scientific Objections to GMOs

31. Should parents be given information about the genetic health of an unborn fetus? The Human Genome

32. Should parents be allowed to select the genomes of their offspring? • Embryos from in vitro fertilization are currently tested before implantation • Many unused embryos are discarded The Human Genome

33. Should parents be allowed to design or correct the genomes of their offspring? The Human Genome