National 5 Biology Unit 1 – Cell Biology

1. National 5 Biology Unit 1 – Cell Biology Section 5 Genetic Engineering https://www.youtube.com/watch?v=7tbxN5uwaqA https://www.youtube.com/watch?v=DmHYUvmiXQI

2. We will be learning…

3. What is Genetic Engineering? Genetic engineering is the process of altering the genetic code of a cell or organism. Using this process, it is possible to take a gene from one organism and put it into a different organism.

4. Why Would we Want to do this? So far, this technology has been used for a variety of purposes. • Making insulin to treat diabetes • Making human growth hormone • To make plants resistant to disease • Spider-goats • Glow-in-the-dark organisms

5. What is Genetic Engineering? • Genetic information can be transferred from one cell to another naturally. This is the basis of sexual reproduction in which genetic information from a sperm cell is transferred to an egg cell during fertilisation. • Some bacterial species can transfer plasmids between them naturally. Viruses carry genetic material into the cells of other species. or by genetic engineering. • In recent decades, scientists have discovered that genetic information can be transferred artificially from cells of one species to the cells of another completely different species using techniques called genetic engineering.

6. This involves the removal of required genes from the chromosome of one organism and their insertion into the chromosome of a completely different organism, usually a bacteria. The technique stems from discoveries made in the early 1970’s: • Bacteria have genetic material in rings, one large chromosomal ring and one or more smaller rings called plasmids. • Plasmids move freely between bacterial cells naturally, carrying their genes with them. This enables a bacterium to acquire completely newcharacteristics. • Enzymes were discovered which could ‘cut open’ and ‘glue’DNA -- the genetic engineer’s “scissors and glue”.

7. loose strand of main DNA plasmid –small ring of additional DNA Genetic engineering is when pieces of chromosome (DNA/genes) are transferred from one organism to another Material is often transferred to bacteria as their DNA is loose in the cytoplasm, making it easy to modify. They also grow and replicate quickly. A new gene can be inserted into the plasmid and the bacteria then produce the protein for which the gene codes.

8. The Steps Involved... • The required gene is located on the donor chromosome. • The gene is removed from the chromosome. • A plasmid is removed from a bacterium. • The plasmid is cut open. • The gene is inserted into the plasmid. • The genetically altered plasmid is inserted into a bacterium. The altered bacterium is propagated in optimum growing conditions to produce many identical cells that can be used as biochemical “factories”.

9. Bacterial plasmid Human DNA with desired gene is located Cut out the gene with endonuclease enzyme Cut open the plasmid with endonuclease Gene inserted into plasmid using ligase

10. Put the plasmid into a bacterial cell Bacteria cell with human gene in it The bacterial cell will make (synthesis) the protein that the new gene codes for.

11. Steps in Genetic Engineering • Label the diagram in your notes • Write the steps below your diagram in your notes: • The desired gene is identified and removed from the chromosome by endonuclease. • The bacterial plasmid is cut open using endonuclease. • The desired gene is inserted into the plasmid using ligase. • The plasmid is inserted into the bacterial cell • The bacterial cell synthesises (makes) the protein coded for by the forgien gene.

12. Advantage of using Micro-Organisms e.g. Bacteria • Bacteria are commonly used because they can be grown quickly and easily, often at low cost. • Given suitable conditions, genetically modified (GM) bacteria multiply at a rapid rate and manufacture large quantititesof a useful product than can then be extracted, concentrated, purified and put to use.

13. Problems with trying to Genetically Engineer a Human • Isolated cells of an advanced multicellular organism such as a human being are often difficult to mass produce in a culture.

14. Uses Genetic engineering has been used for a number of reasons by scientists including: • making medicines • making plants resistant to disease • glow-in-the-dark organisms and cells • an enviropig • the spider-goat. This website lists 12 examples of genetic engineering from around the world.

15. Video clips • TWIG: Genetic Modification clip (2 mins 49 secs) • Animal Farm Channel 4 (episodes 1 & 2 approx 50 mins each).

18. Making Insulin • Insulin is a hormone (made of protein) which controls the levels of glucose (sugar) in the blood. Insulin is normally made by cells in the pancreas. Without insulin, the glucose in the blood is not taken up by the cells, which need the sugar for energy. Instead the glucose builds up the blood and the cells are essentially starved. A person with type 1 diabetes does not make insulin so needs to have insulin injected from another source to keep them healthy GM insulin has some advantages over insulin taken from pigs or cattle: • It is easier to create high quantities of insulin • It is less likely to cause an adverse reaction • It overcomes ethical concerns from vegetarians and others

19. Traditionally, in the days before genetic engineering, people with diabetes were treated with pig or beef insulin. While this did solve the problem, it was not ideal. Some patients suffered strong side effects when using animal-derived insulin. Vegetarians would obviously prefer not to be using a medication obtained from an animal. In recent years, there has been an increase in the number of patients with diabetes – this means more insulin is required and would mean using more and more animals.

20. The insulin gene is cut from the human chromosome and extracted using special enzymes. A plasmid is isolated from a bacterial cell and cut open using special enzymes. The insulin gene is then inserted into the plasmid and joined together using an enzyme called ligase. The new plasmid now contains bacterial information and also the information for making human insulin. This plasmid can be referred to as ‘recombinant DNA’ meaning it has been genetically engineering and combined from different sources.

21. The newly engineered plasmid is now inserted into a new bacterial cell. This cell is now genetically modified. The genetically modified bacterial cell is now left to grow, in a fermenter, and in doing so it produces insulin. The insulin is then extracted and purified so that it can be used to treat the patient. • This OU video also summarises the process focusing on insulin production. It goes on to look at what scientists hope to use genetic engineering for in the future.

24. Future possibilities So… where is this all going? Some scientists are taking genetic engineering a step further. Not content with moving genes between organisms, scientists are now creating genes from scratch – i.e. genes not even found in nature – and creating brand new organisms. Ethics: What do you think?

25. GE in Medicine – Human Growth Hormone Human growth hormone is made by the pituitary gland in the brain and is essential for normal growth and development. Human growth hormone can be made via genetic engineering and can be given to children who are not growing properly. Scientists have known about growth hormones since the 1920s but only began using HGH to treat kids who were unusually short because of pituitary disorders in 1963. Use of the drug was fairly conservative, however, because it was in short supply, due to the fact that there was only one source of HGH—humans. Gathering the drug meant isolating it from the pituitary glands of cadavers,

26. Problems with HGH pre- GM Production • Production of the drug in this way continued for more than 20 years. That all came to a halt, however, with the horrifying discovery that some of the drug was contaminated, having been extracted from a cadaver infected with Creutzfeldt-Jakob disease (CJD). CJD is similar in effects to mad cow disease or accelerated Alzheimer's, causing rapid brain degeneration leading to death within a year of the first symptoms. There is no treatment and no test for CJD, which can lie dormant for decades after exposure before signs of infection appear. • Eventually, 26 people would die of CJD from contaminated HGH. The fact that there was no way to test for infection turned the lives of all of those who had been treated in the 1960s and 1970s into a terrifying waiting game.

27. Advantages to Genetically Engineered Human Growth Hormone • Bacteria can be grown in large fermenters e.g. large quantities can be made • No risk of CJD infections • Cheaper to make/unlimited supply

28. Too little Growth Hormone! Human growth hormone can be made via genetic engineering and can be given to children who are not growing properly

29. Too much Growth Hormone! • Before being banned in 1989, HGH was used by some sports-people to increase muscle size. • In adults, excessive growth hormone for a long period of time produces a condition known as acromegaly, in which patients have swelling of the hands and feet and altered facial features.

30. What is Haemophilia? • Haemophilia is an inherited condition that affects the blood's ability to clot. • Normally, when you cut yourself, substances in the blood known as clotting factors combine with blood cells called platelets to make the blood sticky. This makes the bleeding stop eventually. • However, in haemophilia, there aren't as many clotting factors as there should be in the blood. This means that someone with the condition bleeds for longer than usual. • The condition is passed to a child by one or both of their parents.

31. Factor VIII to treat Haemophilia GM blood clotting factor

32. Genetic Engineering to make Medicines

33. Other Applications You might not realise it but you probably have seen genetic engineering in the News. GM in your cornflakes? Food fears as U.S. approve new genetically engineered maize Minister: Britain will open the door to Frankenstein foodRead more: http://www.dailymail.co.uk/news/article-1284048/Minister-Britain-open-door-Frankenstein-food.html#ixzz2EYvpoEpz 'Enviropigs': genetically modified for food consumption GM food: we can no longer afford to ignore its advantages GM cows make 'low allergy' milk

34. Genetically Modified Organisms A Genetically Modified Organism, or GMO, is an organism which has been genetically engineering. That means that it’s genetic code has been altered in some way e.g. the insertion of a gene from another species.

35. EnviropigTM 'Enviropigs': genetically modified for food consumption The Enviropig was a pig which has been altered to include genes from E. coli (a bacterium) and mice. The inclusion of these genes meant that the pigs were better able to digest their food, making their manure less harmful to the environment. This project was closed in June 2012 due to loss of funding.

36. GM Foods GM Foods are big business around the world and still very controversial for a number of reasons. For the rest of this topic we are going to look at how GM foods are made, why they are made and what issues people have about their production.

39. Psst! Hey kid! Wanna be a superbug? Stick some of this in your genome…. Even penicillin wont be able to harm you! It was on a short-cut through the hospital kitchens that Albert was first approached by a member of the Antibiotic Resistance

41. Advantages and Disadvantages of Genetic Engineering

42. Concerns If the blending of animal and human DNA results, intentionally or not, in chimeric entities possessing degrees of intelligence or sentience never before seen in nonhuman animals, should these entities be given rights and special protections? What, if any, social and legal controls or reviews should be placed on such research? What unintended personal, social, and cultural consequences could result? Who will have access to these technologies and how will scarce resources—such as medical advances and novel treatments—be allocated?

43. Extrinsic Concerns What, if any, health risks are associated with transgenics and genetically modified foods? Are there long-term effects on the environment when transgenic or genetically modified organized are released in the field? Should research be limited and, if so, how should the limits be decided? How should the limits be enforced nationally and internationally?

44. Intrinsic Concerns Are there fundamental issues with creating new species? Are species boundaries “hard” or should they be viewed as a continuum? What, if any, consequences are there of blurring species boundaries? Are chimeras and transgenics more likely to suffer than “traditional” organisms? Will transgenic interventions in humans create physical or behavioural traits that may or may not be readily distinguished from what is usually perceived to be “human”? What, if any, research in genetic engineering should be considered morally impermissible and banned (e.g., research undertaken for purely offensive military purposes)?14 Will these interventions redefine what it means to be “normal”?

45. I can: • State what is meant by genetic engineering • Identify the order of the stages of genetic engineering • Describe the stages of genetic engineering • Give examples of uses of genetic engineering