Lecture 8-Biotechnology

Question 1

What is biotechnology?

Answer 1

is the use of living organisms to make useful products for humans. Modern biotechnology refers to genetic engineering and its associated technologies.

Question 2

Techniques affecting reproductive capacity

Answer 2

In humans, mating is nature’s way of introducing sperm into a woman’s reproductive tract, so that egg and sperm can fuse to produce a child. Sometimes this process that normally takes place very easily does not happen though both sperm and egg appear to be normal. In other cases a woman may want to have a child although she has no male partner. Two techniques that were first used in livestock breeding programmes are now commonly used to relieve childlessness in humans, whatever its cause. These techniques are artificial insemination and in-vitro fertilization

Question 3

Artificial insemination

Answer 3

A woman may be artificially inseminated using sperm from her partner, if he is impotent for some reason, or she may use sperm from a donor as an alternative to adoption, if she is fertile and her partner is not. In this process, medical personnel place sperm in the reproductive tract of a woman. Semen is collected from a partner or a donor depending on the circumstances of the case.

There are registered human sperm banks, where donors leave semen specimens. In some cases donors are paid for their contributions. In reputable facilities, donors are screened for their suitability and their medical and social histories recorded. A physical description and biography is also recorded so that women or couples using the bank can select a donor with characteristics of their choice. For example, if a man is infertile, the couple may want to use donor sperm from someone similar to him in appearance, ethnic group, and educational background. Application and screening processes vary in the strictness of their requirements, but the insemination procedure is not guaranteed to result in an embryo.

Question 4

In vitro fertilisation

Answer 4

Normally, in mammals, fertilisation takes place in a protected environment inside the body. It is possible, however, to fuse sperms and eggs outside of this environment, in a glass dish (a petri dish) in a laboratory. This is in vitro (literally in glass) fertilisation. In humans fertilisation normally takes place in the tubes that carry the eggs to the uterus (womb). Sometimes for different reasons this is not possible, although both sperm and eggs themselves are normal. For example, the tubes may be blocked by scar tissue from an old infection so the eggs cannot pass down the tubes. In vitro fertilisation offers a solution to this problem.

A woman wishing to undergo in vitro fertilisation is first given medication that causes her to produce many mature eggs at one time. These are collected from her, then fertilised in a glass dish with sperm from her partner (or from a sperm bank if necessary). Two to five days later, two to four of the embryos that are developing from the fertilised egg cells are returned to the mother’s womb, to develop in the normal way.

At this time, they are smaller than a pin-prick. The hope is that one or two embryos will grow to term, giving single births or twins. Unused embryos are quickly deep-frozen in liquid nitrogen for possible future use. The success rate is about 20% so most couples have to try more than once. In that event, two to four of their fertilised ova are removed from storage, thawed out, and the implantation process repeated. The rest of the embryos remain in storage.

Question 5

Genetic engineering

Answer 5

is a technique by which genes from one organism can be inserted into the chromosomes of another organism of the same or different species. These chromosomes now carry different information than before and will issue different instructions to the cells that contain them.

Question 6

Process of genetic engineering

Answer 6

The process involves using specific enzymes to cut out short pieces of the DNA from one chromosome and then removing it. The recipient cell’s DNA is cut and the short piece of DNA spliced into it (see figure 4.1). This sounds easy! It is not. It is a very complex process that takes place in many steps.

Question 7

Recombinant DNA

Answer 7

When DNA from two different sources are joined together

Question 8

Gene cloning

Answer 8

The foreign gene is inserted into the DNA of bacterial cells. Bacterial cells reproduce very rapidly. Each cell simply divides in two, making exact copies of itself. This is repeated over and over and in a short time there are thousands of exact copies of the original cell all containing the recombinant DNA strand. Whatever the clones now produce can be isolated and collected for sale or used in other research areas. The importance of this technique is that large quantities of a useful product can be manufactured very quickly and relatively cheaply.

Question 9

Transgenic orgasms

Answer 9

creating animals and plants that can produce larger quantities of useful products or produce products that they do not normally make. When the the new genes they carry are from a different species.

Question 10

The production of hormones

Answer 10

In our bodies there are special glands that secrete substances directly into the bloodstream. They are transported in the blood to the organs or cells where they have an effect. These substances regulate the growth or functioning of specific organs or tissues in the body. For example, the hormone insulin, produced in the pancreas, helps to control the level of glucose in the blood by stimulating liver cells and other cells to remove excess glucose from the bloodstream. The use of recombinant DNA techniques has made possible the large scale production of hormones like insulin. Escherichia coli, a bacterium which normally lives in the gut, is used as a host organism for the human genes that control the production of specific hormones.

Question 11

The gene for human insulin is introduced into

Answer 11

1. DNA strand removed from human cell and gene removed, e.g. gene for making insulin
2. Gene inserted into bacterial DNA
3. Bacterium with recombinant DNA strand cultured
4. As cells multiply, a large clone of recombinant bacterial cells form
5. Clone used for further research or large scale production
6. For commercial purposes, bacteria grown in large sterile vat containing nutrient medium
7. Product, e.g. insulin, extracted from fermenter and purified

Question 12

Genetic engineering large scale production-process

Answer 12

E. coli bacteria which are then cloned. Large quantities of the altered bacterium can be grown in a large vat called a fermenter where they will produce the hormone. Before this technology became available, insulin was obtained from the pancreas of slaughtered pigs and cattle. Some patients were allergic to insulin from these sources and only small quantities were found in each pancreas.
Insulin was therefore extremely expensive and many persons could not afford it at all. Insulin, now produced using a synthetic gene, is used to treat diabetes mellitus. Two other hormones produced using these techniques are human growth hormone and erythropoietin. Growth hormone is produced in a special gland in the brain. It regulates overall body size. A deficiency results in dwarfism. Growth hormone is used to treat dwarfism in children. Erythropoietin is needed for the production of red blood cells in the bone marrow. It is normally made in special kidney cells, but many patients with damaged kidneys cannot make the hormone themselves and so become anaemic.
A mutant strain of E. coli, which can only survive under laboratory conditions, is now used in research. This is a precautionary measure. In the unlikely event of “escape” from the laboratory, the bacteria would die and not be a threat to humans.

Question 13

Antibodies

Answer 13

how the body defends itself against vaccines by producing

Question 14

About antibodies

Answer 14

Antibodies are made by special white blood cells called B cells when foreign substances enter the body.
They fight against these foreign substances and their effects.
Each B cell produces only one type of antibody.
Each antibody is specific to the foreign substance that stimulated its manufacture. Thus, antibodies against measles will have no effect on chicken pox germs.

Question 15

Immunity/pathogens

Answer 15

Disease organisms (pathogens) are “foreign”. If we have an attack of a disease, for example, measles, after we recover, some of our B cells “remember” the attack. If we are infected again by this pathogen, the cells very quickly stimulate the production of large amounts of the required antibody. More than likely, this will mean that we will not get the disease again. We have become immune to that particular disease.

Question 16

How vaccines work

Answer 16

Vaccines mimic the action of this first infection. Each vaccine contains a specific amount of killed or weakened forms of a particular pathogen. These are introduced into the body orally or by injection. The body responds by producing some antibodies. If the same organism in its active form later infects the body, there is the same effect on antibody production as described before. Large quantities of the specific antibody are quickly made and the pathogens destroyed before we get ill. In this way, vaccines make the body immune to the disease.

Question 17

Antigens

Answer 17

It is now known that the substance which stimulates the production of antibodies is in the outer surface of the pathogen. Through recombinant DNA techniques, the genes controlling the pathogen’s surface characteristics can be inserted into a harmless organism. The resulting recombinant organism then produces the antigen from the pathogen and can then be used as the vaccine. This type of vaccine is referred to as a recombinant vaccine. This procedure removes the risk of an active form of the organism being introduced, perhaps during the preparation of the vaccine. Vaccines against smallpox, influenza, Herpes simplex type 1 (cold sores), and hepatitis B, have been prepared by this method. More commonly used are subunit vaccines. This is where the antigen alone is isolated and used as the vaccine.

Question 18

Prenatal diagnostics

Answer 18

Genetic abnormalities may be detected either during development of a baby before it is born (foetal development), or during adult life. In order to detect such abnormalities in the foetus, amniocentesis FD12A 223nTHINK ABOUT IT! Do parents really have the right to choose the characteristics of their children? may be used. In this process, a fine needle attached to a syringe is inserted into the amnion or protective fluid-filled case in which the baby is developing. Some of the fluid, in which there are cells from the embryo, is withdrawn. These cells are grown in special media until enough are available to carry out the required tests. The numbers of chromosomes, as well as the chemical structure of the genes can be determined in these tests. The tests show whether or not the sequence of the bases on the chromosomes is normal (see Module 2 Unit 3). Amniocentesis is particularly useful in those situations where disorders like haemophilia already exist in a family, or for late pregnancies where the risk of abnormalities developing is greater than in younger mothers. It allows parents to make informed decisions as to whether to continue or terminate a pregnancy.

Question 19

Other diagnostic tests

Answer 19

Another way of getting large amounts of an antibody is to use hybridomas. This is done in vitro by fusing a B cell, the special antibody producing white blood cell, with a cancer cell. Cancer cells have the ability to multiply rapidly and indefinitely. A B cell normally makes small quantities of antibody, and lasts only a few days. However, when it is fused with the cancer cell, the hybrid cell continues to multiply. The new cell can also be cloned. Many new cells can be produced that are genetically identical with the parent cell and with each other. So large amounts of antibody can be produced from these multiple hybridomas. Antibodies prepared by this technique have been used for various diagnostic tests. The specific antibody is brought into contact with some substance carrying the antigen with which it will react. The reactions cause a change that can be detected in some way. The speed with which results are obtained is an advantage.

Question 20

Some tests prepared by antibodies technique are:

Answer 20

(a) Pregnancy tests. These are based on recognition of a hormone, the human chorionic gonadotropin (hCG) by the appropriate antibody. Within a few days after conception, a signal is sent from the developing placenta to the ovary to produce the hormones which will prevent the mother from menstruating FD12A 224and so losing the baby. This signal is carried by hCG. Within about two weeks after conception, hCG can be detected in the urine. The pregnancy test uses antibodies to detect hCG in a sample of urine. The results are ready in five minutes.
(b) Differentiating between chlamydia and gonorrhea infections in the female genitals. The results are available in 15 to 20 minutes, as against days, if routine culture methods were used.
(c) Recognition of herpes simplex type 1 virus, which causes cold sores, and herpes simplex type 2 virus, which causes genital herpes. Results are known in 15 to 20 minutes.
(d) Diagnosis of streptococcus throat infections: This is immediate.

Question 21

Forensic medicine

Answer 21

DNA fingerprinting has been popularised by the exposure it receives in court cases and crime stories on television. The technique is useful in forensic medicine as it allows minute quantities of body fluids or tissues to be identified accurately even several years after a crime has been committed. The DNA of each of us is as unique as our fingerprints. In order to prepare DNA “fingerprints”, DNA is treated with enzymes to break it up into fragments of various sizes. The pattern of sizes of DNA fragments is unique for each family line. Except for identical twins, each person has different combinations of the genetic material from the mother’s egg, and the father’s sperm. So the pattern of fragments can be used as fingerprints for identifying individuals precisely. In practice, scientists look at several DNA regions and use the information to create a DNA profile. The likelihood of finding anyone else with the same profile for a particular set of regions is remote. The patterns are recognised by DNA probes. These are molecules labeled with a radioactive isotope, dye or enzyme, which will highlight a particular sequence on the DNA molecule.
DNA fingerprints from blood or semen stains on a victim may be compared with fingerprints from the blood of suspects. In this way, guilt or innocence may be established. DNA fingerprinting can be used to identify the remains of missing persons by comparing a tissue sample with one obtained from the belongings of the person. In cases of disputed paternity prints of the child, the mother and the alleged fathers are compared for similarities. The technique is also useful in transplant programmes for matching organ donors with persons needing to receive the organs.

Question 22

Medical research
Transgenic animals with human genes

Answer 22

Plants or animals with recombinant DNA are termed transgenic or genetically modified organisms. Transgenic organisms can now be patented. These organisms have been of immense value in medical research as there are limited possibilities for conducting experimental research in disease on humans. One example of this is a transgenic strain of mice that was created and used extensively in cancer research. These mice carry genes for certain types of cancer and researchers can study these diseases and possible cures without taking risks with human patients. Transgenic animals have been reared to produce in their milk rare and expensive proteins for use in medicine. For example, in the United Kingdom, sheep have been engineered to produce AAT (alpha-1-antitrypsin) in their milk. AAT regulates the breakdown of elastic fibres in the lungs. Where the gene for producing AAT is defective, too many fibres are broken down and patients develop emphysema. Obtaining AAT from sheep’s milk opens up an avenue for developing effective treatments.
Research is also being directed at the possibility of manipulating special cells in the body’s defense system in such a way that they destroy cancer cells without damaging normal cells and tissues.

Question 23

Preventing rejection of transplants

Answer 23

There are also possibilities for using genetic engineering to prevent the rejection of transplants. Transplanted tissues are recognised as foreign by the body’s immune system. Antibodies react to molecules on the cell surface membranes, treat them as antigens and destroy the transplanted tissue. Research is being done to produce pigs that do not carry the antigen. These pigs will carry a human gene for a cell surface membrane molecule that would prevent attack by one of the body’s defence systems. These transgenic pigs could then be bred to supply material for transplanting into humans. This is still in the future.

Question 24

Gene therapy

Answer 24

One of the most exciting and controversial areas of medical research using genetic engineering techniques is in gene therapy. This area of research offers the possibility of curing genetic diseases and defects. It relies on the in vitro fertilisation methods that allow access to sperms, eggs, and embryos before or immediately after fertilisation. The intention is to replace a defective gene with a healthy one. The healthy copy of the gene will be passed on to all other cells of the embryo as it grows by mitosis and since it will form part of the genetic makeup of the adult it can be inherited by future generations of that parent. The controversy relates to the perception that geneticists are tampering with nature.

Question 25

Stem cell research

Answer 25

There are about 220 different types of cells in the human body, for example, muscle cells, blood cells and bone cells. Early in the development of an embryo, cells are present which have the potential to become the various types of specialised cells. These “primitive” cells are called stem cells. In the orderly development of the embryo, cells like these from different regions of the embryo will mature into particular types. The aim behind stem cell research is to harvest and grow these immature cells and use them to replace tissues lost by injury or incurable diseases such as diabetes, Parkinson’s disease, multiple sclerosis, Alzheimer’s and others. The technique for harvesting stem cells and maintaining their growth in the laboratory is now available. To mid-2001, they have been used to produce about 110 different kinds of cells. Embryos used for this research are obtained from stored unused embryos left from in vitro fertilisation procedures.
The problem is that harvesting the stem cells results in the death of the embryo. In any case, this source of embryos is not nearly enough for the desired scope of stem cell research. Embryos would have to be deliberately produced for this specific purpose. Are there any other possibilities? There are within our bodies, sites at which new cells are being made all the time and from which stem cells can be harvested. They have been obtained from the brains of cadavers, from living bone marrow, and from human placental tissue. However, extracting the cells from these sources is difficult and supplies fewer cells of limited potential. For example, stem cells which will produce cardiac cells or pancreatic islet cells have not yet been found in adult tissue. (The special patches of tissue that make insulin in the pancreas are known as the islets of Langerhans.)

Question 26

Stem cell research pt 2

Answer 26

The difficulty of obtaining useful stem cells in sufficient quantity to increase the pace and range of stem cell research has given rise to another controversy: the cloning of human embryos. In cloning, new individuals are produced from a single “parent”, without the fusion of gametes. These individuals therefore have a genetic makeup that is identical to the one “parent” and to each other if several of them are made. (When we make several cuttings from a favourite plant to get many plants, all of which have the same characteristics of the original “parent”, we are also producing a clone). Adult mammalian cells do not have the capacity to grow into complete new organisms on their own.

However, scientists have discovered that transferring the nucleus from an adult cell into an egg cell, after removing its nucleus, will produce a cell that is able to grow into an embryo. When the cell starts to multiply, the new cells can be separated and each one continues growing, multiplying the number of available embryos. Stem cells from these embryos would then be available in larger quantities for research. An animal that is a replica of the parent that donated the nucleus can develop from each embryo.

Question 27

Stem cell research pt 3

Answer 27

Britain has been considering making this source legal, with the proviso that all such embryos must be destroyed after 14 days. This precaution would prevent the development of cloned foetuses or babies. One consideration driving the British interest in this procedure is the possibility of using it to produce replacement tissues that are of the correct genetic makeup of a patient that needs these tissues. If the patient’s own DNA were to be placed in an egg cell stripped of its DNA, and the stem cells from this embryo then used in the patient’s treatment, there would be little risk of rejection, since stem cell and patient DNA would be identical. Therapeutic cloning is the term being used to describe the process. Many people have reservations about these procedures. Those against the use of embryonic stem cells from whatever source regard the unavoidable destruction of the embryo in the process as taking a life. This brought research in the United States to a standstill for some time. However, limited permission to continue the work has been granted by the present administration. Medicine has already reaped many benefits from biotechnology, and the potential is there for many more. But the use of the techniques and products poses many questions and raises many issues.

Question 28

The Human Genome Project (HGP) What is a genome?

Answer 28

is simply all the genetic material, the DNA, of an organism.

Question 29

The Human Genome Project- Dna and all that

Answer 29

We are reminded from Unit 3 that the DNA molecule is made of two strands of phosphate and sugar units twisted together into a spiral. The two strands are linked together through a sequence of four special substances – adenine, thymine, cytosine, and guanine. Each link is made up of a pair of these substances. But adenine is always linked with thymine (A-T or T-A), and cytosine with guanine (C-G or G-C). The sequencing of the pairs is precise, and acts as a code for the making of a particular protein. The arrangement of these pairs is unique for each species. In other words, it differs from one species to another. That is why species differ! The human genome is believed to have about three billion of these pairs. Genes are portions of DNA molecules. It is estimated that there are about 30,000 to 35,000 genes in humans. (How many base pairs are there in one gene?)

Question 30

Objectives of the Human Genome Project

Answer 30

The Human Genome Project aims to identify all the pairs and genes in the human genome and use this information to create a genetic map that would allow researchers to locate a particular gene, when necessary. (Producing this map could take more than one lifetime! It FD12A 231has become possible by developing super computers programmed to sequence genes.) At the same time, they intend to address the ethical, legal, and social issues which may arise from the project. Nonhuman organisms commonly used in research, are also to be studied. These include the bacterium Escherichia coli, commonly found in the gut, the fruit fly, and mice.

Question 31

Participants and the timeframe

Answer 31

The Project is international. Participating countries include Australia, Brazil, Canada, China, Denmark, the European Union, France, Germany, Israel, Italy, Japan, Korea, Mexico, Netherlands, Russia, Sweden, the United Kingdom, and the United States. Originally scheduled to last 15 years from 1990, the expected completion date is set at 2003. In June 2000, the first working draft of the genome was published (See Nature, February 15, 2001 and Science, February 16, 2001.) It should be noted that this is not the only project in the race to map the human genome.

Question 32

Possible Application

Answer 32

The research has applications for molecular medicine. For example, clearer identification of the genes associated with genetic disorders should lead, not only to improved diagnosis, but also to greater control in gene therapy.

Question 33

Biotechnology and agriculture- plant and animal breeding story

Answer 33

The story is told of a European explorer in South America who had heard legends of great treasure hidden in caves by one of the Amerindian tribes of the region. He and his group went to great lengths to find this treasure and were sorely disappointed when it turned out to be large jars of seeds. What he did not appreciate was that these seeds were the result of years of work. They had been carefully selected from the most productive plants season after season and were indeed a treasure. Plant and animal breeding is not new. Farmers have been using these biotechnological techniques to improve their crops and animals for thousands of years. Deliberate cross-breeding was introduced much later. Farmers sought to produce plant crops that were more resistant to disease, or animals that gave more milk.
In Trinidad and Tobago at the Cocoa Research Unit (CRU) of the University of the West Indies (UWI) is the world’s most important gene banks for cocoa plants.
The CRU are keepers of the international Cocoa Germplasm Collection, preserving some 2,500 genetic varieties from all over the world. Collection started in the 1920s by the Imperial College of Agriculture, which in 1962 became the Faculty of Agriculture of the UWI. Professor John Spence headed the unit for many years. The plants are carefully nurtured and maintained as a source of breeding material for researchers, plant geneticists and commercial breeders. Cross-breeding in cocoa in Trinidad and Tobago has resulted in the production of much sought after hybrids that are resistant to some diseases, but maintain a high flavour. Within recent years, modern biotechnological approaches are being used to maintain and upgrade the collection, for example, the collection is now being genetically fingerprinted.
Also in Trinidad and Tobago, selection and breeding from different breeds of water buffaloes (not by crossing cows and buffaloes as is commonly thought) over many years have produced the Buffalypso. This buffalo type is much in demand as it produces good quality beef and milk on very poor quality feed, making it ideal for countries that spend large sums importing animal feed or beef. Similarly, in Jamaica, work by Dr. Thomas Lecky gave rise to the Jamaica Hope breed of cattle, a great milk producer and all round animal that is well suited to tropical conditions such as ours. Both these types of cattle have been exported to many different countries in the world.

Question 34

Tissue culture

Answer 34

Another biotechnological technique of great interest, is tissue culture. Using this technology, very small portions of a plant can be stimulated to produce hundreds of new plants that are all of the same quality as the original parent plant? What is most interesting about this method is that complete plants can be grown from a few cells from virtually any part of a plant: stems, roots or leaves! These techniques were developed in the 1930s with the knowledge that all cells have a complete set of genetic information to make a whole animal or plant of the same species. Normal cells usually confine their activities to whatever the particular set of tissues to which they belong, should be doing. Muscle cells for example, make new muscle cells and use energy to contract. The rest of the genetic information is switched off and lies dormant for the rest of the organism’s life. Researchers found out that they could switch on the rest of the genes in many plant cells by using a careful mix of water, minerals, sugars, vitamins, and plant growth substances (sometimes called plant hormones).
Tissue culture is carried out under sterile laboratory conditions where light and temperature are also controlled. In order to produce enough food for a growing world population and to make agriculture commercially viable, farmers have tended to cultivate staple crops, over extensive areas. This is how bananas, sugar, and coconuts are grown on estates in the Caribbean.
This is termed monocrop agriculture, in contrast to the mixed cultivation that is characteristic of small farmers and home gardeners who often grow many different crops together, which is how plants grow in nature.

Question 35

Newer methods of obtaining new plant varieties pt 1

Answer 35

Genetic engineering is now used in agriculture to make direct modifications of the DNA molecule. This means that scientists are now working at the molecular level. Traditional cross-breeding is at the level of the whole organism, and tissue culture at the cell level. It is now possible to enhance the characteristics of food crops by introducing copies of genes for desired traits into the DNA of the plant. This has several advantages:
-Plant breeders can now develop varieties that were not possible using traditional cross-breeding methods because genes can be copied from different species of plants, from animals, and microbes. Traditional cross-breeding was between varieties of the same species.
-There is greater control over what is copied. The gene that is copied is usually one with characteristics that are well understood.
-Transferring single genes is superior to crossbreeding as it is highly selective. With cross-breeding, it is possible that both desirable and undesirable traits would be inherited since whole chromosomes are involved in fertilization.
New varieties of crops can be developed more quickly. Older methods of cross breeding could take many years or even decades.

Question 36

Newer methods of obtaining new plant varieties pt 2

Answer 36

These new techniques have already been used to develop food crops that:
- are more resistant to pests, disease, and poor soil and weather conditions,
- tolerate chemical herbicides better, l can be processed more easily,
-exhibit improved nutritional content, l have better physical characteristics such as appearance, texture, and size.
The tomato plant has been injected with a gene for an insecticidal protein, with the result that when an insect eats the transgenic plant, the protein is released and the insect dies.

Question 37

Developing substitutes for existing plant products

Answer 37

For several years now the sugar industry has been in crisis throughout the Caribbean. As wages and transport costs increased locally the market price for our sugar became less attractive. However, this is not the only reason. Countries that used to purchase our sugar can now make their own sweeteners, thanks to genetic engineering. Corn-based fructose sweeteners are now available cheaply and have all but killed the market for the sucrose produced from sugar cane and beet. This research was spearheaded in the first world countries that previously provided us with markets. Perhaps we need to consider using genetic engineering to develop a new variety of sugar cane that can produce a different and more marketable product.

Question 38

Developing animal varieties pt 1

Answer 38

The emergence of genetic engineering has also impacted significantly on animal production and animal health. As is the case with plants, the technology can be used to improve the quality of animal stock. In the traditional forms of breeding, only animals that are closely related could be cross-bred. Mention was earlier made of the Buffalypso and Jamaica Hope cattle, bred for meat and higher milk production respectively. Selection and cross-breeding took place at the level of the whole animal. The new technology allows for individual genes to be swapped between unrelated species, the exchange taking place at the molecular level. The resulting transgenic animals carry desirable genes that were not initially part of their make-up. For example, transgenic pigs have been produced which have a higher growth rate and better quality meat than previously. The gene of the growth hormone, bovine somatotropin (BST) from cattle has been inserted into bacteria which then reproduce, making large quantities of BST. In this case the bacteria are the transgenic organisms. The hormone is then extracted and injected into cows to stimulate greater milk production.

Question 39

Developing animal varieties pt 2

Answer 39

The health of animal stock can be improved with the help of genetically engineered vaccines. Microbes are made to produce large amounts of the specific antigens associated with particular diseases. Vaccines are then made from these antigens (see Session 1). In Australia, animal vaccines have been produced to counteract diarrhoea in piglets and parasites that affect sheep

Question 40

Genetically modified foods

Answer 40

The first genetically modified food (GMO) to be sanctioned by the Food and Drug Administration in the United States of America was the “Flavr Savr” tomato. It was sanctioned in May 1994. The tomato has been genetically designed so that it does not soften easily and can, therefore, be left on the plant until ripe. This ensures that its flavour is properly developed. This contrasts with “natural” tomatoes which must be picked at the onset of ripening to prevent softening; such tomatoes do not stay on the tree long enough to develop their full flavour. It has been estimated that gene-altered corn and soybean products are being used to make about 4000 food products that are sold in American supermarkets, including corn flakes, potato chips, veggie burgers, fresh garden produce and cooking oil with reduced saturated fat. It is highly likely that many of these products can be found on the shelves of any Caribbean supermarket.

Question 41

Intro to genetically modified foods -concerns and issues

Answer 41

Many individuals see the development of foods that have been genetically modified as the route to providing large yields to meet the world’s demand for food. Farmers and produce merchants also benefit commercially and there are others who think this is the driving force behind the research. Concerns about the safety of genetically modified foods have been expressed all over the world. Recent standards adopted in the USA for labelling foods as organically grown include certifying that they do not contain products from genetically modified organisms.

Question 42

The concerns that have been expressed include the following:

Answer 42

-Food that contains products from GMOs does not always carry labels that would alert the public to its nature and/or method of preparation. Policies for labelling GMOs are not uniform. The European Union and countries such as New Zealand and Australia are pursuing mandatory labelling of these products. However, the United States is using a system of voluntary labelling as the main strategy. In the Caribbean, both Jamaica and Trinidad and Tobago have begun drafting relevant policies and other territories are now discussing this issue. Should there be a regional policy?
-Though some testing of genetically modified foods has been done, the testing is not as extensive as it should be and appropriate testing procedures have not been developed in some instances.
- Some persons have suggested that the increase in children of hypersensitivity diseases such as allergies and asthma may be due to genetically modified foods to which they are exposed.
-Although there are perceived advantages such as tastier fruit, there may be unintended changes in the plant and if such plants are cross bred with other varieties, a harmful variety may result.

Question 43

Production of alcohol formula

Answer 43

Glucose à carbon dioxide + alcohol + energy

Question 44

Some current uses of biotechnology in industry Preventing and remedying environmental degradation

Answer 44

Chemical industrial processes tend to produce waste materials that may be hazardous to the environment. In contrast, biotechnology based manufacturing tends to produce wastes that are recyclable and biodegradable. For example, producing the antibiotic cephalosporin using methods from modern biotechnology instead of chemical methods is cost effective because less is spent on the measures previously needed to protect the environment. Similarly, it has been estimated that there could be energy savings of up to 30% when biotechnological methods are used to treat wood pulp instead of thermo-mechanical methods, for example in making animal feed.
Besides preventing environmental degradation, biotechnological methods can also be used to remedy damage that has already taken place. Living organisms have been used to modify and destroy chemical wastes making them harmless to the environment. Typically, bacteria or fungi that can digest the waste are genetically engineered to produce more effective strains that can get rid of the waste quickly. In the case of oil spills, genetically engineered bacteria have been produced and used to clean up waterways. This contrasts with previous methods, for example, using detergents that often did more damage than the oil spills.

Question 45

Enzyme technology

Answer 45

Older methods of making cheeses and alcoholic beverages relied on the enzymes produced by micro-organisms to convert milk or sugar into the products to be sold. The enzymes can now be made and extracted from genetically engineered bacteria in large quantities for use in industry. One familiar use of enzymes is in washing powders. Believe it or not, the world’s first enzyme detergent was patented in 1913 but it was not very successful. Enzymes from genetically engineered micro-organisms are now used in manufacturing cheeses, in brewing, making biscuits, and sweets. They are also used in the textile and leather industries.

Question 46

Creating new products

Answer 46

In manufacturing, biotechnology has led to the creation of a wide range of products including biodegradable plastics, biopolymers, and biopesticides. Also, an additional source of alcohol is now available. Normally in the manufacture of alcohol, yeast acts on glucose after it is broken down from more complex sugars like cane sugar. Yeast now exists in a genetically altered form, which can break down a different sugar, lactose or milk sugar. Whey, a waste product in the manufacture of cheese, contains lactose. So this waste product can now be used for making alcohol.

Question 47

Considering issues in biotechnology- the ownership of knowledge

Answer 47

Biotechnology has become an industry; it is now big business and growing rapidly. One of the most contentious issues surrounding the industry is the fact that most of the research in the area is no longer in the public domain. This is to be expected. When large pharmaceutical corporations spend millions on research in the hope that the outcome will benefit them they are within their rights to protect their discoveries. However, this goes against all that we have said about the nature of scientific scholarship. Science has progressed because researchers across the world have always shared their knowledge. In this way scientists were able to build on what others had accomplished. This is no longer the case.

Question 48

Considering issues in biotechnology-patenting

Answer 48

In 1980, a patent was granted in the United States for a genetically engineered “oil-eating bacterium”. The organism was to be used for cleaning up oil spills. It was said to be a “non-natural man-made microorganism”. Since then, several patents have been given, for example, for genetically modified bacteria, viruses, plants, and hormones. In 1988 a transgenic mouse to be used in cancer research was patented. Herman, the world’s first transgenic bull was created in Europe. The issue of patenting Herman’s new genes that would make his female offspring less likely to get mastitis, has not yet been settled. Some companies afraid of exposing what they have discovered to their competitors, refuse to file patents for their discoveries. They consider them trade secrets. Already there have been attempts to patent human genes by the scientists working in the Human Genome Project. Some are of the view that the scientist who identifies a gene should “own” it.

Question 49

Biosafety and environmental hazards- The rate of effects of the new technology

Answer 49

The rate at which new biotechnology processes produce results allows little time for observing environmental interactions at any level, molecular, cellular or whole organism. Therefore there is no time to correct or defuse errors that may have disastrous results.

Question 50

Biosafety and environmental hazards-the dangers of release

Answer 50

Many pharmaceutical and other companies use genetically engineered organisms to make their products. There is concern for the workers in these facilities should these organisms escape. Adequate safeguards seem to be in place in these fermentation plants. In some cases the micro-organisms are also genetically engineered so that they cannot survive outside the specific conditions of the fermentation vats in which they live. The greater danger is the use of genetically engineered micro-organisms that are deliberately released into the environment. For example, strains of bacteria that can fight certain diseases in crop plants can be sprayed on them for this purpose. Scientists post materials to each other around the world. These might escape from a torn package. The fear is that some previously unknown and dangerous effect might follow. There is no way to recall or destroy these bacteria once they enter the environment. ? FD12A International policy as laid out in the Cartegena Biosafety Protocol, adopted at a Conference of Parties to the United Nations Convention on Biological Diversity, 1999, and the Codex Alimentarius of the Food and Agricultural Organisation (FAO), address these concerns. These can help to prevent misuse and accidents arising out of genetic engineering that could have irreversible effects but they do not remove the danger altogether.

Question 51

Biosafety and environmental hazards-competition with natural species

Answer 51

Another concern is that genetically engineered organisms may escape into the wild and flourish at the expense of natural organisms, wiping out whole varieties. This is a major concern with respect to genetically engineered plants, many of which are in use now. Plants spread their genes in pollen grains and seeds that are difficult to confine to one area.

Question 52

Social and economic issues Are genetically modified organisms the new economic weapon?

Answer 52

Developing genetically modified organisms is expensive business. Large companies with great economic resources stand to gain most from technologies such as genetic engineering. GMOs can become a new economic weapon in a number of ways. Patents are being taken out on genes from tropical crops or plants with medicinal qualities. Farmers in developing countries will derive no benefit from these discoveries and stand to lose some of their markets (as happened with sugar) as the products made by these methods can be cheaper and more effective, thus more competitive.

Large companies, because of their economic strength, can force poorer governments to accept their genetically modified exports, affecting the livelihoods of farmers and farm workers. Reduced earnings mean a lowering of the quality of life of these individuals and of the economic circumstances of the countries to which they belong.

Question 53

Can the developing world afford the new technologies?

Answer 53

Cuba has successfully entered the field of biotechnology. An existing excellent health service is the base on which their enterprise has been built. The UWI has biotechnology centres on its three campuses, where research is being carried out and on the university campus in Trinidad and Tobago the tissue culture facility is commercially viable. It is not impossible or unrealistic for institutions and governments like ours to follow Cuba’s lead. Although we may not have individual companies and corporations in the region with the wherewithal to pursue such research our governments and institutions like the university can work together on selected projects of mutual benefit.

Question 54

Ethical considerations
The right to modify life

Answer 54

Humans have been modifying living things for hundreds of years. Many breeds of dogs provide pleasure to their owners no matter how ridiculous they appear to us. These have all been “created” by humans. Breeding plants and animals for pleasure or profit has not raised many questions but many feel the new technology is going too far.

Question 55

Ethical considerations
Lack of privacy in data banks

Answer 55

Scientists working on the Human Genome Project and others in public and private institutions discover and locate precisely genes that cause or predispose individuals to certain diseases. As more and more of these genes are found information is piling up in data banks that are like libraries. The information is important for other researchers but use of the banks can be abused. It is feared that employers or insurance companies, for example, can use information about a person’s genetic make-up to discriminate against them. An insurance company may refuse to insure someone with a predisposition to heart disease. An employer may fire a 23-year-old worker carrying the gene for Huntington’s chorea although he may not become ill for another 25 years.
It should be clear to you that to begin thinking about these questions at all, people need to have some basic information about what is going on. We hope you are now in a better position to make more objective decisions should you be asked to contribute to a debate on any of the issues raised.

Question 56

Summary

Answer 56

Biotechnology is the use of living organisms to make useful products for humans. Modern biotechnology refers to genetic engineering and its associated technologies.

Biotechnology and medicine
Techniques covered included artificial insemination, in vitro fertilisation, genetic engineering, and gene cloning. Some of the uses of genetic engineering discussed include making safe vaccines, cheaper production of hormones, prenatal diagnoses for genetic defects in foetuses, and pregnancy tests. In forensic medicine the use of DNA fingerprinting was seen to be a useful tool for making positive identifications and matching tissues of donors and recipients for transplant surgery. In medical research genetic engineering centred on the development of transgenic animals with human genes making experiments possible that cannot be done on humans. The controversial areas of gene therapy and stem cell research were also discussed. The mapping of the human genome and the many possibilities it offered were described briefly.

Biotechnology in agriculture
In this section the main focus was on examples from the Caribbean of work done to enhance the characteristics of some commercially important plants and animals. Methods used include plant propagation by tissue culture and genetic engineering of new varieties. The “old” technologies of plant and animal breeding were also seen to have made an important contribution to Caribbean agriculture

Biotechnology in industry
In industry genetic engineering has contributed bacteria with genes for making a wide range of products in ways that are cleaner and more environmentally friendly than the older technologies. Products include foods, enzymes for washing powders, and bacteria for cleaning up oil spills.

Issues and concerns
Several issues concerning the safety of the new technologies for humans and the environment were discussed as well as possible social and economic effects on the developing world. The ethical issue of “tampering with life” was also raised.