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Welcome to the World of Biotechnology An introduction into the business of biotechnology for high school students Modified from a ppt found at https://www.georgiastandards.org
What is Biotechnology? • Let’s break it down: • Bio - alive or living • Technology - the application of science to achieve industrial or commercial objectives • So basically, we’re talking about using living materials for a commercial or industrial purpose • Taking living cells and putting them to work for us!!!
Origins of Biotechnology • Although it seems like a new thing, biotechnology has actually been around a while • Domesticated plants and animals are the result of selective breeding (have you ever seen a wild corn plant, not something you’d want to eat) • Using yeast to make bread rise • Using bacteria or yeast to ferment grapes into wine
So Why Should I Care? • Biotechnology affects all aspects of your everyday life, including: agriculture and food safety, healthcare, law enforcement and environmental issues • Although there are many great career paths involving biotechnology that you may consider, possibly even more importantly, you will soon be voters • You’ll make decisions on the ethics involving legalizing certain types of research • You might be on a jury where biotechnology plays a key part in the evidence presented
The Biotechnology Toolbox • Today, biotechnology is used in three main ways: • Directly using cells • Placing yeast into a bioreactor to ferment grapes • Using the proteins/enzymes made by cells • Isolating antibiotics from bacteria for use in human medicine • Using the genetic material inside of cell • DNA profiling
Just Some of the Latest Advances in the World of Biotechnology • Cloning • DNA profiling • Genetically modified bacteria to synthesize products • Genetically modified foods
Cloning • Creating a genetically identical copy of something (ex. a DNA strand, a cell, an organ or an entire organism) • Single cells and DNA are fairly easy to clone and so this has been done for a comparatively long amount of time • Cloning entire organisms becomes increasingly more difficult the more complex the organism is (ex. Humans are harder to clone than worms) and so it is very recent and for some species has not been perfected yet
How Cloning Works • DNA is extracted from an adult (somatic) cell • An egg for this same species has it’s DNA removed • The empty egg is filled with the adult DNA • An electrical current is applied to the egg • The egg is implanted into a surrogate mother • The baby born from this egg is genetically identical to the adult from which it was cloned • But, it will not share any characteristics that aren’t genetic • It will not be the same age as the animal it was cloned from (it’ll be a baby)
Cloning Reproductive cloning Use to make two identical individuals Very difficult to do Illegal to do on humans Molecular cloning Use to study what a gene does Routine in the biology labs gene 1 gene 2 There are two VERY different types of cloning:
Reproductive cloning cell from the body remove nucleus and take the rest of the cell take the nucleus (containing DNA) Clone identical to the individual that gave the nucleus Dolly the sheep egg Dolly the sheep was the first cloned mammal. To make Dolly, scientists took the nucleus out of a normal cell from a sheep. They put that nucleus into an egg cell that had no nucleus. They then had a new cell. This process is called Somatic Cell Nuclear Transfer (SCNT)
Reproductive cloning cell from the body remove nucleus and take the rest of the cell take the nucleus (containing DNA) Clone identical to the individual that gave the nucleus Dolly the sheep egg To make the new cell start to divide and grow, they gave it an electric shock. Then it started to divide and develop into an embryo. When it had grown into a very early stage embryo called a blastocyst – a ball of just 50-100 cells – it was implanted into the womb of another sheep so that it could grow into a lamb and be born.
Reproductive cloning cell from the body take the nucleus (containing DNA) remove nucleus and take the rest of the cell Clone identical to the individual that gave the nucleus Dolly the sheep egg The new sheep is a clone of the sheep from which the nucleus was taken at the start of the process. Both sheep have the same DA. Not only sheep have been cloned. Scientists have now cloned many different animals, including mice, cats, dogs, frogs, goats, horses, pigs, rabbits and others. However, it is a difficult process and does not always work. It is illegal to clone a human being in this way.
Molecular cloning: Principles 1) Take DNA out of the nucleus gene 2 gene 1 cell 1 cell 2 • Molecular cloning is a process used by scientists to make copies of a particular gene or genes inside a cell. They use the technique to find out more about what certain genes do or how they work. Molecular cloning is done routinely in laboratories today. It involves several steps: • Take the DNA out of a cell.
Molecular cloning: Principles 2) Make a new piece of DNA gene 1 gene 1 2) Cut out the gene you are interested in (gene 2 in this example). Insert it into a strand of DNA taken from another cell. The gene is not literally cut out with a knife or scissors – carefully chosen enzymes break the DNA chain at particular points. More enzymes are used to insert the gene into another piece of DNA at exactly the right place (in this example, next to gene 1). gene 2 gene 2
Molecular cloning: Principles 3. Once you have made a piece of DNA containing the gene you want to study, put your new DNA into a test cell. When the cell divides, it makes copies of itself. Each new daughter cell contains an exact copy of the DNA in your test cell, including genes 1 and 2. The genes have therefore been copied and we say they have been cloned. 3) Put new DNA into a test cell and grow copies Daughter cells contain same DNA: Genes 1 and 2 have been cloned gene 2 gene 1 cell divides insert new DNA
Molecular cloning: Principles This is a simplified description of the technique. There are some intermediate steps involved and the details of the technique can vary, but this scheme illustrates the key principle, i.e. we are able to make cells containing particular genes in order to find out what those genes do. Some examples of how this technique can be used are given on the next slide. 1) Take DNA out of the nucleus gene 2 gene 1 cell 1 cell 2 2) Make a new piece of DNA gene 1 gene 1 gene 2 gene 2 3) Put new DNA into a test cell and grow copies Daughter cells contain same DNA: Genes 1 and 2 have been cloned gene 2 gene 1 cell divides insert new DNA
Molecular cloning: Applications Molecular cloning is an important tool used by scientists to learn more about the roles of genes in development and disease. Some examples of how molecular cloning can be used in the lab are: Loss of function remove a gene to see if anything works differently Loss of function (often called “gene knockout”): a common technique that has been very useful in helping scientists understand how particular genes are involved in disease. A gene is removed or blocked so that it does not work, and then scientists watch to see what happens. This has been of such wide benefit for science and medicine that the scientists who developed this technology were awarded the Nobel Prize for Medicine in 2007. eye Normal mouse embryo gene A missing gene is involved in giving the eye its colour
Molecular cloning: Applications Reporter gene: this generally involves using colour to help scientists easily see when a particular gene is working. A ‘reporter gene’ is added to the DNA of cells. This reporter gene makes the cells produce a coloured protein – for example, a blue protein. The reporter gene is put into the cells’ DNA right next to another gene (gene x) that scientists really want to investigate. Wherever gene x is active (or ‘switched on’) in a cell, the reporter gene is also active. This means the cell makes the blue protein and looks blue. So, it is easy to see which cells have an active gene x because those cells are blue. Reporter gene add a gene that shows us when another gene is working gene is active in blue areas only
Molecular cloning: Applications Lineage tracing: this involves looking to see what happens to a cell’s daughter cells, and their daughters, in a developing animal. First, some cells are marked by giving them a gene that scientists can easily see working, e.g. a gene to make a protein that is a fluorescent green colour. This makes the cells look green. Every time the cells divide, their daughter cells inherit the gene for the green protein, so the daughter cells are green too. This allows us to see when their marked cells divide and where they end up as an animal develops. Lineage tracing mark a group of cells to see where their daughter cells end up gene is passed on to cells all over the body
Why Clone? • To create identical cells for research purposes • To maintain a genetically desirable species of plant or animal • To create a missing organ or tissue for treatment of human diseases • To save endangered or extinct species
DNA Profiling • Identifying the pattern of certain sequences in parts of a person’s DNA to determine if two samples come from the same person, related persons or two, non-related individuals • Only parts of the DNA sequence are used because the whole genome is too long to sequence repeatedly • Everyone has a unique sequence of DNA (even identical twins, although their genomes would be very close to identical) • In order to be an effective tool, we need to get DNA from many people to determine how often certain patterns show up in the population
How DNA Profiling Works • The DNA is isolated from a cell sample and many copies are made with a process called Polymerase Chain Reaction(PCR) • The DNA is cut into pieces using restriction enzymes (they cut only at specific sequences) • The DNA is run on a gel electrophoresis to separate the pieces (separated based on size) • Probes are used to find certain DNA sequences (usually VNTR sequences) • Comparisons of these pieces of DNA are made to determine identity or relationships
What can DNA profiling be used for? • To determine if a suspect was at a crime scene • To identify a murder victim • To identify a soldier killed in the line of duty • To determine identity • Paternity/maternity tests
Genetically-Modified Bacteria • Inserting new genes into a bacteria to trick it into making a product for us • Although each bacteria usually doesn’t make much product, millions of bacteria can be grown in bioreactors at the same time, and the product harvested from all of them at once
How are Genetically-Modified Bacteria Created? • A piece of DNA containing the gene for the desired product is cut with restriction enzymes • A plasmid (circular bacterial DNA) is cut with the same restriction enzyme • The piece and the plasmid are ligated (fused together) • The plasmid is transformed into the bacteria • The plasmid either stays in whole or the gene crosses over into the bacteria’s DNA
Some Products Now Synthesized by Bacteria • Biodiesel fuel • Chemicals to block an HIV infection • Photographs • Human insulin for diabetics • Plastics
Genetically-Modified Multi-Cellular Organisms • Livestock or produce that has received new genes to make the product healthier, resistant to pests or durable for travel • The process is similar to that used to create genetically-modified bacteria, but the genes are being inserted into multi-celled organism instead
How GMO are made • The process varies slightly between each species, particularly between plants and animals, however some aspects are the same • Changes are made to the organism’s DNA by inserting a useful gene into the egg cell • This changed egg is then implanted into a mother and the baby born hopefully has the desired trait
Why make GMOs? • To give plants resistance to certain pests without the use of pesticides • To make plants drought resistant • To make cows that produce more milk • To make vegetables that can undergo long transport without over-ripening • To make chickens that contain extra vitamins that may be missing from our diets
The Ethics of Biotechnology • Despite all the exciting things that biotechnology can do or will do in the near future, there are things to consider: • Would it be ethical to clone a human? Why or why not? • Should your insurance company be allowed to have access to your DNA profile if it detected some disease? • How can the bacteria in bioreactors be disposed of once they are no longer useful? • What happens to the natural balance when GMO are sent out to compete with natural plants in the environment?
Conclusion • We are at the cusp of an exciting time in the world of biology • We are capable of manipulating living cells in ways that would have been unimaginable even 20 years ago • With this new technology comes many new jobs and benefits to mankind • With this new technology comes the need to think through the ethical issues that arise and to wisely weigh the benefits against the drawbacks to make informed decisions as to what research should be encouraged and what should not