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9.6 Option – Biotechnology: 6. Applications
and areas of research
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6. There are many
applications and areas of research in
biotechnology
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Students learn to:
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Students:
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Extract from Biology Stage 6 Syllabus (Amended October 2002). © Board of Studies, NSW.
Prior learning: Stage 4-5 Syllabus,
4.8.3(b) and 4.8.4(a) and (e); 5.8.2(a), (c) and (d).
H.S.C. module 9.3 (subsection 5)
outline one way that forensic scientists can use DNA analysis to help solve cases
- If semen can be obtained in a rape case the person whose semen it is can be identified by doing DNA analysis on the sample and then testing the suspects to see if there is a match. This is a much more accurate method than methods used previously.
- Briefly one method is:
- Scientists find the markers in a DNA sample by designing small pieces of DNA (probes) that will each seek out and bind to a complementary DNA sequence in the sample. A series of probes bound to a DNA sample creates a distinctive pattern for an individual. Forensic scientists compare these DNA profiles to determine whether the suspect's sample matches the evidence sample.
- A marker by itself usually is not unique to an individual; if, however, two DNA samples are alike at four or five regions, odds are great that the samples are from the same person.
- Alternately DNA analysis can be used to show that a person is innocent who was said to be guilty before DNA analysis was available. A sample of the incriminating blood or semen must still be available.
Further information can be found on
forensic science using DNA analysis 
, The Human Genome
Program of the U.S. Department of Energy, Office of Science,
USA.
identify data sources, gather, analyse and process information to present one case study on the application of biotechnology in each of the following:
- medicine
- animal biotechnology
- aquaculture
These case studies should:
- give details of the process used
- identify the organism or tissue involved
- describe the outcome of the biotechnological process
- evaluate the efficiency of the process and discuss advantages and disadvantages associated with either the product or the process
- There is a lot of information on the Internet about biotechnology so choose your sites carefully. Universities and government web sites should have accurate information and the site should still be there if you want to go back later to check some information. You could also identify current journals and mass media magazines as data sources. It is important to remember that scientific journals are peer reviewed (checked by other scientists who work in the same field) but anyone can put information on the web.
- When you have identified enough good sources use them to gather information on each of the points listed above. Some sites and texts may be general and will cover some or all of the points but you may also like to look at specific sources on each one. While you are gathering your information keep in mind the four points that the case studies must include.
- Analyse and process the information you have gathered to decide on a suitable case study to present.
Some websites on the application of biotechnology to medicine, specifically on tissue engineering, that may be useful are listed below.
Future technological trends and their likely effects on human society, politics and evolution
Tissue engineering used for jejunal flap prefabrication - Biomedical EngineeringThis web site is about biotechnology and aquaculture.
Biotechnology in Aquaculture: The future of fish farming
describe one
example from the following applications of biotechnology in
medicine:
- tissue engineering using skin transplantation as an example
- gene delivery by nasal sprays
- production of a synthetic hormone, such as insulin
Tissue engineering using skin transplantation
- Novartis launched tissue engineering in 1997 with Apligraf, (Graftskin), a product developed by partner Organogenesis, for the treatment of venous leg ulcers. Apligraf, a bi-layered skin substitute, has since been approved for use in the treatment of diabetic foot ulcers of greater than three weeks duration. Additional markets for this unprecedented procedure are anticipated, with a pivotal trial underway assessing the success of a product that reduces scarring after skin cancer surgery.
Another website for tissue engineering in the skin Skin and Laminar Structures
Development of new rheumatoid arthritis "nasal spray"
- In August 2004 scientists at King's College, London announced an exciting new gene therapy treatment for rheumatoid arthritis (RA) that could be given to patients via a nasal spray or nose drops. The research, still in the laboratory stage, could lead to clinical trials on patients within three years.
A team has carried out preliminary work using nose drops in a model system to deliver a modified gene coding for a naturally derived anti-inflammatory substance called Interleukin-10 (IL-10) for the treatment of RA, a joint condition that affects around 350,000 people in the UK.
They have made the novel and exciting observations that IL-10 administered in this way acts by "switching off" the harmful, inflammatory process that causes RA, and “switching on” populations of cells that can re-educate, or hold in check, the harmful cells. Therapeutic delivery of IL-10 has been developed by international research groups to suppress inflammation in RA, but has been shown to cause side effects such as generalised immunosuppression when delivered by intravenous injection.
However, the team is hopeful that administering the IL-10 gene via the nose will more effectively and efficiently target a population of cells that will hold in check the specific cells that cause disease, rather than affecting the whole immune system, so avoiding side effects. It also could be cheaper than current drugs being used.
"Every step we take we are thinking about patients, and we hope this research will lead to a clinical trial when it is completed in three years' time," explained Dr Klavinskis, the team leader.
Production of a synthetic hormone such as insulin
- In 1978, a synthetic version of the human insulin gene was constructed and inserted into the bacterium Eschericia coli, in a laboratory at the University of California at San Francisco, USA. Insulin is a protein, and like all proteins, it consists of a chain of building blocks called amino acids. The order of amino acids in a protein is unique to that particular protein. When the sequence of amino acids is known, the corresponding sequence of DNA can be isolated (or in this case, chemically synthesized) and introduced into bacterial cells to make the human protein.
To accomplish this, the piece of foreign DNA is first inserted into a plasmid, a small circle of DNA which serves as a carrier. The new "recombinant" plasmid carrying the human gene is then reintroduced into another bacterial cell. Once inside the cell, the human gene on the plasmid can be read by the cell's protein-making machinery.
At the time, the approach that the scientists took in synthesizing a gene was unheard of. Today, however, this approach is more common, and other methods of directly or indirectly isolating human DNA are used more routinely. Recombinant human insulin was developed by the company, Genentech, in October of 1982, the first product of modern biotechnology. Since that initial success, the application of biotechnology to human medicine continues to grow at a phenomenal rate. Recent advances allow insulin analogues or copies to be produced. They can produce insulin with different properties such as early onset of effect or longer lasting. Insulin treatment for diabetes, Types of Insulin
describe one example from the following applications of animal or plant biotechnology:
- the production of monoclonal antibodies
- recombinant vaccines to combat virulent animal diseases
Background information
Antibodies are made by B-lymphocytes as part of the immune system. Each antibody is specific to a particular antigen. The antigen may be bacteria, viruses or other foreign cell in the body or a toxin produced by bacteria. Antibodies bind to the antigen and inactivate it so it can’t harm the animal host. Thus antibodies bring about immunity to a disease. Antibodies are specific to only one antigen
Monoclonal antibodies
- Monoclonal antibodies are produced by fusing the antibody producing mammalian cells (B-cells) with cells that will continue to replicate endlessly. These latter cells are usually harmless tumor cells. The result of this cell fusion is called a hybridoma. The hybridoma can then continue to produce antibodies in culture as long as they are needed.
- Their specificity makes monoclonal antibody technology so valuable. Not only can antibodies be used to protect against disease; they can also help to diagnose a wide variety of illnesses, and can detect the presence of drugs, viral and bacterial products, and other unusual or abnormal substances in the blood.
More information can be found at Access Excellence.
Recombinant vaccines
- Instead of growing viruses in eggs or other hosts, recombinant vaccines are produced by producing only one viral protein (ie, not the whole virus) in a yeast or bacteria. The vaccine is then incapable of infection through accidental failure to kill all virus particles. Secondary inoculation could occur, but it would be extremely unlikely through semen, and infection could not occur, since the vaccine never had infectious capability in the first place. The time decay of viral protein must be fairly short, so a blood donation a day or so after vaccination would probably not contain any viral protein. Drawbacks would include allergic reactions to the preservatives or to small amounts of proteins from the bacteria or yeast.
describe one example from the following applications of aquaculture:
- the production of a pharmaceutical from alga
- the farming of a marine animal
You only have to describe one example but two will be given here so you can choose one of them.
The production of a pharmaceutical from alga
Background information
Algae are a diverse group of plant–like organisms most of which live in fresh or sea water. The types are brown algae (kelp), red algae, green algae and microscopic algae. They don’t have true stems, roots and leaves like plants do. They vary from huge kelp that can be up to 100 metres to tiny microscopic algae that can’t be seen unaided. Algae are very important as the basis of most food webs in oceans and streams. Photosynthesis by algae provides about half the material provided by photosynthesis on a global scale and the majority of this comes from microscopic algae.
A pharmaceutical is a chemical that is administered to treat or cure disease. It may also have the goal of enhancing physical or mental well-being.
- Seaweeds and other algae are rich natural sources of essential amino acids, polyphenol glycosides, minerals, hydrosoluble vitamins and trace elements. In colour cosmetics, some iron oxide pigments can be replaced with green, red, blue, brown and yellow algae. All these materials have strong antioxidant action.
- Brown algae contain alginic acid, which is a mucilaginous polymer with a structure similar to that of cellulose. It is used in the manufacture of pharmaceutical and cosmetic creams.
- Microscopic algae have been found to contain compounds with anti-cancer properties, and with potential for use in much-needed new-generation antibiotics. Nutritional supplements and cosmetics, have also been identified in Australian microalgae. The biotechnology potential of Australia's oceans is a major focus of a national collaborative CSIRO project called the Bioactive Molecules Initiative.
The farming of a marine animal- Freshwater Yabbies
Background information
The freshwater yabby ( Cherax destructor) is perhaps Australia's best known freshwater crayfish. Recently the yabby has gained a strong following among gourmet chefs as a tasty new addition to restaurant menus and, as a result, the demand for yabbies is increasing.
Yabbies occur throughout arid south-eastern inland and central Australia and have the largest distribution of any Australian freshwater crayfish species.
Yabbies naturally occur in a diverse array of both temporary and permanent habitats and are adapted to varying climates. For instance, yabbies naturally inhabit streams and lakes of the snow-covered alpine regions of southern NSW, the billabongs, floodplains and rivers of the Murray-Darling Basin. The yabby is a hardy species able to tolerate a wide range of environmental conditions. It is therefore an excellent candidate for farm-based aquaculture throughout much of Australia.
- Farmers have frequently grown yabbies in their dams, either for personal use or to supplement their income. The yabbies ate the food available to them in the dam.
- Recently there has been a movement towards supplementary feeding with food grains (i.e. lupins), better water quality management, and the establishment of purpose-built ponds (so called semi-intensive aquaculture).
Development of a genetically improved strain of yabby
- If farmers want to increase production from their farming venture they can simply increase the amount of pond or dam area on their farm or can increase the yield of crayfish from ponds. This can be achieved by increasing the average weight of crayfish harvested, or by speeding up the time taken for crayfish to reach market size. Yields can be increased by increasing temperature, using high quality feeds or by genetically improving their stock.
- One advantage of genetic improvement over the manipulation of the environment is that the progress is permanent and sustainable for long periods of time. It is also generally less labour intensive or expensive to instigate than environmental control as this may fluctuate from pond to pond and/or season to season.
- The culture of yabbies is currently based on individuals derived from unselected wild stocks. There has been little effort to identify a 'superior' strain of yabby, or to select for traits that have economic importance such as growth rate. For profitable aquaculture, an ideal freshwater yabby should grow quickly to market size, efficiently convert food into meat, have a high yield of edible flesh, and be very tasty when cooked. Ideally, females should not begin to reproduce until they are larger than market size. In this way, growers will be able to maintain control over densities in grow-out ponds or dams.
- Unfortunately, yabbies currently used in commercial aquaculture do not fit this ideal model. This is not surprising considering that in their native habitat, natural selection has favoured animals that are intermediate performers. The poorest rarely survive to reproduce due to fitness reasons, while those that grow the quickest, mature later or best utilise available food resources, are generally the favoured target of predators (including humans). It is likely that natural selection favours wild populations that are intermediate in performance. However, contained within these populations, at low frequencies, are yabbies with great genetic potential in performance traits such as rapid growth, late maturity and efficient food conversion ratios.
- In order to utilise this natural variation, Livestock Industries has undertaken research at Armidale to identify yabby populations with characteristics that will render them more profitable for aquaculture. To do this, the research team is employing genetic technology regularly used in livestock production to produce a strain of yabby with performance characteristics significantly better than those stocked in farm dams or specialist grow-out ponds. In addition the research will examine ways to produce single sex and/or sterile yabbies so that farmers can more efficiently control densities in their ponds.
This information was taken from CSIRO Information Sheet, Farming freshwater yabbies.
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