Genetic engineering 2/28/20 Key words: Insulin, Enzymes, Plasmids Starter: What have these pictures got to do with todays lesson? The big picture: What is genetic engineering? Learning outcomes To describe what genetic engineering is using examples. To analyse how human insulin can be produced in bacteria. To evaluate the pros and cons of producing insulin this way.
What is genetic engineering? Scientists can add, remove, or change an organisms genes to alter its characteristics it is genetically modified (GM) Genetic modification works in animals, plants and microorganisms Example of genetic engineering How its been modified Benefits/ risks or
side effects? Examples of genetic engineering Look at the presentation showing examples of genetic engineering. You should fill in your table as you read about each examples. GloFish Originally created in an attempt to show levels of pollutions in rivers. Native to India and Bangladesh. None have survived in American rivers.
Zebra fish with a gene inserted from jellyfish or coral to make them fluoresce. The first genetically engineered organism to be sold as a pet. How does this fish They can reproduce, but it is illegal to do so! benefit us? Other fluorescent organisms Superspuds The Protato contains 60% more protein per gram than a normal potato, it also
has a larger yield. Could the Protato face the same opposition as Amflora? A gene was used from the grain Amaranth which codes for storage protein. In tests with rats and rabbits there have been no side effects and no allergic affects. Amflora Potato created for the starch industry. Used antibiotic resistance marker gene.
Fear that the genes could escape into the environment. It was proposed that the waste potato was fed to livestock. This caused outrage from some European countries, why? Golden Rice Genetically engineered rice which contains a gene from carrots (or other vegetable) which causes the rice to contain the building blocks for vitamin A production in the body. Vitamin A deficiency causes blindness and death. Some people think that GM
crops like this one promote the use of GM foods to people that are not in the position to say no. 125 million children suffer from vitamin A deficiency. Most of these children live in developing countries where rice is the staple food. Too much vitamin A causes other health problems. Spider-Goat Spider silk is stronger than steel, lightweight, and very elastic. It holds its strength between -40C and 220C.
Spider silk could be used to manufacture; replacement ligaments wound covering (it has antiseptic properties and vitamin K which helps with blood clotting!) Goats which produce spider silk in their milk! optical communications The gene transferred from a spider causes the goats to produce an extra protein in their milk which can be extracted and spun into spider silk thread. bullet proof clothing waterproof clothing!!
Spiders cannot be farmed as they are cannibalistic About 75% of spider goats are euthanised as there are strict controls meaning that they cannot leave the facility where they are created. they eat each other! Why create a life to destroy it? AquAdvantage Salmon
This fish has not been consumed by humans yet is it safe? What affect could the AquAdvantage salmon have on wild salmon if it escaped? A gene which controls the growth hormone from one breed of salmon is inserted into the DNA of another. This causes it to grow much quicker than normal salmon. Could this gene be
transferred to humans if we eat it? What could happen if this occurred? AquAdvantage salmon Normal salmon Venomous cabbage Cabbage which has been genetically engineered to include the gene for Scorpion venom. This reduces the use of chemical pesticides sprayed on crops. The venom is poisonous to caterpillars it acts as a pesticide.
The toxin has been altered - it does not kill human cells What if the toxin mutates and alters again? What affect will the toxin have on the biodiversity of the area? Flavr Savr Tomato Normally, tomatoes are picked while green and transported many miles before being sprayed with ethylene to ripen them. This prevents damage and perishing on the journey. The Flavr Savr tomato is a genetically engineered tomato which has a gene
inserted to extend shelf-life by slowing down the rotting process. The Flavr Savr tomato was the first GM fruit to be sold in the World. Is it better to spray tomatoes with ethylene than genetically engineer them? Banana Vaccine Bananas, carrots, potatoes and lettuce have all been genetically engineering to deliver vaccines for diseases.
The banana has been the most successful in testing. Is there a risk of people taking the vaccine without realising they are doing so? When the gene has been inserted into the banana, its cells produces virus proteins (not the infectious part). When you eat the banana you ingest these proteins and the body produces antibodies against them this is exactly how injected vaccines work! The virus genes are
transferred to the banana cells and become a permanent part of that bananas genetic code. Human insulin What is insulin used for? To control blood sugar levels Where can we get it from? Pigs and cows What are the problems with using animal insulin in humans? Not enough can be produced 2.6 million people suffer
from diabetes in the UK. Some people think it is ethically wrong. May not work as well. Against some religions. GM insulin has solved this problem! Task 1. Cut and stick the pictures in the correct order to show how human insulin can be produced by bacteria. 2. What are enzymes and why are they used in this process. Put the process in the correct order. What are the enzymes used to cut and join the DNA fragments?
Not all bacteria take up the plasmid! There are 3 possible types of colony that may grow in this process: 1. Some from bacteria that did not take up the plasmid. 2. Some from bacteria that have taken up a plasmid that has not sealed in a copy of the gene but has sealed up on itself to reform the original plasmid. 3. Some the ones we want that have taken up the recombinant plasmid. We call these TRANSFORMED bacteria. Replica Plating
The bacteria are grown on standard nutrient agar, so all bacteria cells grow to form colonies. Some cells from the colonies are transferred onto agar that has been made with ampicillin, so that only those that have taken the plasmid will grow. Some cells from these colonies are transferred onto agar that has been made with tetracycline so only those that have taken up a plasmid that does not have the insulin gene will grow. Replica Plating By keeping track of which colonies are which, we know that any
bacteria that grow on the ampicillin agar, but not on the tetracycline agar, must have taken up the plasmid with the insulin gene. We can now identify the colonies we want and grow them on a large scale. These bacteria then produce insulin on a large scale which can be harvested for use. Pros and Cons Read the statements as a table and produce a table of pros and cons in producing insulin using genetic engineering.
Antibiotic resistance can spread because the antibiotic resistance gene acts as a marker to show which bacteria contain the insulin gene. Many religions disagree with producing pig/ animal insulin. More insulin can be produced using genetic engineering. Unknown long term side effects of using bacteria to produce insulin. Cow/ pig insulin may not work as well as human insulin. It is wrong to alter the genes of any organism. New, harmful strains of bacteria could be produced. It is cheaper to produce GM insulin. GM insulin is the only way we can meet the
increasing demand of this drug. Genetic engineering produces human insulin.
