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BiologyHSC CourseStage 6

Blueprint of life

Part 5: Playing with nature

Incorporating October 2002

AMENDMENTS

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Part 5: Playing with nature 1

Contents

Introduction ................................................................................3

Artificial selection .......................................................................5

Artificial insemination ...........................................................................6

Artificial pollination................................................................................9

Cloning................................................................................................10

Transgenic species ..................................................................13

Producing transgenic plants .............................................................13

Producing transgenic animals ...........................................................15

Examples of GM species ...................................................................16

Genetics and ethics .................................................................19

GM products and labelling ................................................................21

Additional resources ................................................................23

Suggested answers .................................................................27

Exercises – Part 5....................................................................29

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Introduction

If you are fairly confident that you understand most of the first four parts of this module then

you have learnt the basics of evolution and genetics. In this part of the module you are going

to need to use this knowledge to understand how humans are manipulating nature.

Before humans came along, random events and natural selection had been responsible for

distributing all of the life forms throughout the biosphere. Through selective breeding,

humans have changed some species to suit their needs. Reproductive techniques such as

artificial insemination, artificial pollination and cloning have accelerated this selection

process.

You will be shown some of the techniques used to purposely alter, or engineer, the genetic

composition of organisms. These processes are called genetic engineering and it has the

potential to alter the path of evolution.

Biotechnology is the deliberate introduction of foreign genes into the chromosomes of plants

and animals to alter their characteristics and to create brand new organisms. The altered or

new organisms created are called transgenic species and this part explores the ethical issues

arising from the development and use of biotechnology. You will be given information about

a genetically altered plant (Bt cotton) and animal (OncoMouse®) so that you can discuss the

potential impact on genetic diversity.

Gene science has advanced to the stage where its applications have the potential to

revolutionise life itself. The biotechnology industry is rapidly becoming a giant. The need

for public debate is greater than ever. Issues involving the genetic engineering of crops are

very topical and genetically modified food (GM food) has quickly become a household term.

By the time you have finished working through this part you will have become more aware of

how genetics is playing with Mother Nature and how this is changing future evolution.

In this part you will have the opportunity to learn to:

• identify how the following current reproductive techniques may alter the genetic

composition of a population:

– artificial insemination

– artificial pollination

– cloning

• outline the processes used to produce transgenic species and include examples of this

process and reasons for its use

• discuss the potential impact of the use of reproduction technologies on genetic diversity

of species using a named plant and animal example that have been genetically altered

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In this part you will have the opportunity to:

• process information from secondary sources to describe a methodology used in cloning

• analyse information from secondary sources to identify examples of the use of transgenic

species and use available evidence to debate the ethical issues arising from the

development and use of transgenic species.

Extract from Biology Stage 6 Syllabus © Board of Studies NSW, originally issued 1999. The most

up-to-date version can be found on the Board's website at

http://www.boardofstudies.nsw.edu.au/syllabus_hsc/syllabus2000_lista.html

This version October 2002

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Artificial selection

The first chapter of Charles Darwin’s On the origin of species is entitled ‘Variation under

domestication’ where he presents many examples of how domesticated plants and animals

have changed over time to become better adapted to human needs. He explains these changes

as:

man’s power of accumulative selection: nature gives successive variations; man adds them

up in certain directions useful to him.

In agriculture and horticulture, humans purposely choose particular organisms from which to

breed. The organisms are selected because they have certain characteristics that people want.

Productive food, champion racehorses, colourful flowers and prize-winning pedigree dogs

have all been the result of artificial selection (selective breeding).

The first domestication of food plants probably took place between 10 000 and 13 000 BC in

Southeast Asia where crops such as rice and beans were planted and harvested. The Fertile

Crescent, which includes parts of present-day Iraq, Iran, Turkey, Lebanon, Israel and Jordan,

were other sites where crops like wheat where developed. Animals, such as the horse,

donkey, camel and sheep, were domesticated as well. Early farmers took advantage of

naturally occurring genetic differences to produce higher percentages of desirable genes.

It was not until Gregor Mendel’s work concerning the genetic basis of inheritance that plant

and animal breeding would have a scientific foundation. This foundation permitted rapid

advances in breeding techniques beginning in the 1900s.

Today biotechnology plays an important role in artificial breeding in the laboratory. No

longer do scientists have to wait for a whole generation to pass to see the effects of artificial

selection. Through cloning and genetic engineering the whole process can be sped up.

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What is artificial selection and what is the history of this process?

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Check your answer.

Artificial insemination

Artificial insemination was first developed for breeding cattle and horses and is used

extensively in Australia in the dairy cattle industry. This is an animal breeding process in

which male gametes (the sperm or spermatozoa) are collected and introduced artificially into

the female genital tract for the purpose of fertilisation.

This technique enables superior males to inseminate many more females than would be

possible by natural mating. Semen from good bulls is used to inseminate about 1 000 to 2 000

cows a year. By natural methods the same animal would be lucky to inseminate 100 cows.

Semen can also be frozen and transported cheaply over great distances.

Comment on the impact this artificial insemination practice could have

on the future genetic composition of cattle.

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Check your answer.

Other artificial methods for achieving fertilisation have since been devised. Many of these

methods are expensive and are only used when fertilisation is strongly desired. This may be

for the production of endangered species, valuable agricultural or pet species or to overcome

human infertility.

Human reproductive technologies

Artificial insemination techniques have been developed to help with human fertility. About

one in six couples suffer from problems of infertility at some time in their lives. There are

many different causes of infertility. Some are always present; others are gained through life.

Human infertility has been overcome in many cases with the recent introduction of the

following kinds of reproductive technologies.

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In vitro fertilisation (IVF)

A different method of artificial insemination is the mixing of sperm and ovum in a nutrient

medium outside the woman’s body. The term test tube baby comes from this procedure

because the gametes are usually mixed and fertilised in a glass test tube. The name in vitro

fertilisation comes from the Latin word for glass is vitrum (hence in vitro).

The IVF technique is used when a woman’s fallopian tubes (oviducts) are blocked. The

procedure is summarised as follows.

• Basic screening tests are performed on both partners. The results of the tests enable the

clinic to find out if the female can make sufficient follicles (egg-containing structures) and

eggs. It also checks the health of the sperm.

• All parties sign consents.

• The woman is stimulated with injected medications to produce multiple egg development.

These injections continue for about 8 to 10 days.

• Blood and ultrasound testing is done every 1 to 3 days to monitor the development of the

follicles in the ovaries. A minimum number of follicles (4 to 5) are needed.

• When the woman’s follicles are mature, a procedure is performed to remove the eggs from

the follicles.

• The eggs are then fertilised in the laboratory with her partner’s sperm.

• The embryos are cultured in the laboratory for 2 to 6 days.

• One or two embryos are transferred to the woman’s uterus where they hopefully implant and

develop to result in a live birth.

• If there are unused embryos (of sufficient quality) beyond the number that is transferred,

many couples prefer to have them frozen (cryopreserved) for use in a future procedure if this

one fails or the couple want another child in the future.

The first baby born as a result of such a procedure was the English test tube baby, Mary

Louise Brown, in 1978. Controversies have arisen over the legal and ethical status of some of

these procedures, which have been widely used.

Zygote intrafallopian transfer (ZIFT)

In some cases, zygote intrafallopian transfer (ZIFT) is used instead of conventional IVF. If

the male has severe infertility or if there has been difficulty in confirming fertilisation with

past procedures, ZIFT has the advantages of allowing fertilisation to be confirmed and has a

higher success rate than IVF.

ZIFT is just a variation of traditional IVF. With this procedure the fertilised egg at the two-

cell stage, called a zygote, is transferred back into the woman. This fertilised egg is placed

directly into the fallopian tube hence the female partner has to have at least one functioning

fallopian tube.

Gamete intrafallopian transfer (GIFT)

Gamete intrafallopian transfer (GIFT) was developed in 1984 as a variation of in vitro

fertilisation. The main difference between GIFT and IVF is that, with GIFT, fertilisation

occurs naturally within the female partner’s body instead of in the laboratory.

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The developing embryos remain in the fallopian tube and then move naturally to the uterus

for the natural implantation process. GIFT is sometimes selected based on a couple’s

religious beliefs that prohibit conception outside the body.

These reproductive technologies have allowed many couples to have children who would

have been unable to reproduce naturally.

Comment on the future genetic composition of the human race if these

practices continue.

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Check your answer.

Artificial pollination

In flowering plants, pollination is the transfer of pollen from the anther to the stigma. After

pollination and fertilisation, a fruit develops.

There are two types of pollination.

• Self-pollination occurs when the pollen is transferred from the anther to the stigma on

the same flower or from another flower on the same plant.

• Cross-pollination is the transfer of pollen from one plant to the flower of a genetically

different plant or variety.

Artificial pollination is the deliberate selection of useful plant varieties by breeders. It

involves selection and cross-pollination to produce varieties and hybrids with traits desired by

horticulturists. Gregor Mendel used these techniques on his famous experiments on pea

plants.

The selection of more successful plant varieties dates from the beginning of agriculture itself.

The deliberate interbreeding of plants carrying desirable characteristics has been practiced for

thousands of years. Artificial selection and breeding of plants has progressed at an

accelerated rate since the introduction of sophisticated plant breeding techniques.

Describe how artificial pollination of certain plants may alter their genetic

composition.

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Check your answer.

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Cloning

A process called vegetative propagation, or cloning, reproduces plants like bananas, grapes,

pineapples and sugarcane. This is an asexual method of reproduction that includes budding,

grafting, stem cuttings and the growth of plant tissue in a nutrient media. The advantage of

this type of propagation is that the desired clone can be rapidly multiplied for use as a

commercial crop.

A clone is an identical organism or group of genetically identical individuals descended from

the same parent by asexual reproduction. Many plants, such as grasses, show this by

producing buds, suckers, tubers or bulbs to colonise the area around the parent.

Some animals produce clones of themselves; for example, aphids. In the early embryo, each

of the cells has the potential to create a whole organism. Identical twins are examples of

clones.

Is that ewe Dolly?

Cloning came into the spotlight in the media in 1997 when Dr Ian Wilmut and his team at the

Roslin Institute in Scotland created a lamb named Dolly.

A cloned animal can be produced in the laboratory by splitting early embryos and culturing

them to produce two or more from the original egg.

Another technique called nuclear transfer works by transferring the nucleus of a body cell

into an egg that has had the nucleus removed.

Dolly was cloned by the nuclear transfer technique with her DNA coming from a single cell

taken from her mother’s egg that is then fused with a mammary cell (thus the name Dolly

after Dolly Parton).

The fused cell then develops into an embryo that is implanted in a ‘surrogate’ sheep. A

surrogate is one who takes the place of another, so the surrogate is an animal that acts in the

place of a mother. The surrogate is not the mother because none the genetic material in the

embryo comes from the surrogate.

The embryo grows into a lamb that is genetically identical to the donor sheep.

The process to clone Dolly is illustrated on the following pages.

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A body cell is taken from a donor ewe andplaced in a low nutrient culture. This starvesthe cell and stops it from dividing.

donor cell

donor

1

2

DNA

An unfertilised egg cell is taken fromanother ewe and the nucleus with its DNAis sucked out.

blackface ewe

egg cell

fused cell

The two cells are placed next to each other andgiven an electric pulse. This mimics the burstof energy at natural fertilisation causing celldivision to begin.

3

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fused cell

4

embryo

The resulting embryo is implantedin the uterus of another ewe.

The cloning of Dolly is the most famous example of cloning. Find out more

about how Dolly was produced or learn about other examples of cloning.

Use books, your local library or the Internet.

There are some useful sites on the Science webpage for you to start with at:

http://www.lmpc.edu.au/Science

Problems with cloning Dolly

Cloning animals is not an easy task. It took more than 277 attempts before Dolly was created.

The mitochondrial DNA from the donor was not transferred so that Dolly was not a complete

clone and it now appears that Dolly is aging prematurely. All of these problems highlight the

difficulty of cloning adult mammals.

Now complete Exercise 5.1.

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Transgenic species

During the 1970s, a discovery that certain enzymes have the ability to cut and splice

hereditary material of living organisms expanded and sped up the use of reproductive

technologies. These methods, called recombinant DNA technology use special enzymes

called restriction enzymes to cut the long DNA molecules of living matter into pieces as

small as one gene in length.

Once the chromosomes are split, millions of copies of the gene are made through a

polymerase chain reaction. (Polymerase is an enzyme that is able to make this duplication

reaction happen very quickly.) Then these genes are inserted into other cells.

There is more explanation about how genetic engineering is done in the fact sheets in the

Additional resources section.

There are some useful sites on the Science webpage to help you understand

the technology better. The website is at:


Transgenic species are created by taking a gene from one species and inserting it into another

species.

Producing transgenic plants

There are four main reasons for producing transgenic plants. These are:

• to increase yield

• to increase quality

• for pest and disease resistance

• to produce drugs.

Transgenic plants can be produced by several methods. The four main methods are outlined

below.

Method 1: Agrobacterium tumefaciens

Agrobacterium tumefaciens is a soil bacterium that has been doing genetic engineering of its

own for millions of years. It does this by inserting some of its genes, in the form of a

structure called a TI plasmid (a tiny ring of DNA), into the chromosomes of plant cells.

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plasmid

bacterial DNA

A bacterium showing its plasmid.

In nature, Agrobacterium uses its ability to add genes to plants to help it to survive and

reproduce. The foreign DNA (in a plasmid from the bacterium) causes some plant cells to

form tumours that produce unusual compounds (opines) that serve as food for the bacteria.

That is, this bacterium is a naturally occurring genetic engineer that has evolved the ability to

alter plant cells to provide its own food.

Agrobacterium can be manipulated to insert selected genes into broadleafed plants such as

tomato and soybean. Genetic engineers do this by splicing desired genes into an

Agrobacterium’s plasmid. The Agrobacterium inserts the plasmid into a plant cell’s

chromosomal DNA. The targeted plant cell is then coaxed into developing into a complete

fertile plant that will pass on the engineered DNA, with all its accompanying genes, to its

offspring.

plant cell

plasmid

bacterialDNA

plant nucleus

plasmidDNA

Bacterium withplasmid attachesto plant cell

Bacterium insertscopy of plasmidinto plant nucleus

Plasmid with newgenetic informationnow incorporatedinto plant DNA

As plant cellsreproduce theyreplicate the foreigninformation alongwith their own DNA

Genetic engineering with an Agrobacterium.

When a gene that produces a desired protein is removed from a plant or animal cell and

spliced into a bacterium’s plasmid, the gene will continue to produce its designated protein

product in its new bacterial setting. Provided with a nutrient-rich environment, the bacterium

quickly grows and divides, producing more cells that also contain the foreign gene.

This gene will produce the desired protein which can then be harvested from these bacterial

chemical factories. With this technique, bacteria have been genetically engineered to produce

such protein products as insulin, human growth hormone, the antiviral drug called interferon,

as well as thousands of other important protein substances.

Method 2: The gene gun

The gene gun shoots small gold or tungsten particles that have been coated with DNA into a

plant cell. Some of these will introduce new DNA into a cell and then these plant cells are

grown into transgenic plants.

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Method 3: Electroporation

By applying short electrical pulses to plant cells that have had their cell walls removed, it is

possible to produce pores in the cell membrane that will allow foreign DNA to enter a cell.

The cells that incorporate this foreign DNA into their genome can then be grown into plants.

Method 4: Microinjection

Microinjection is suitable for plant and animal cells. DNA is absorbed into liposomes, which

are hollow fatty molecules. These are then injected into a cell. Some of the DNA may be

incorporated into the cell’s genome.

Producing transgenic animals

All animal cells can be traced back to one cell at the start of their lives. By changing the

genetic make up at this point, all future cells will carry the genetically engineered DNA.

The main method of producing transgenic animals is through the process described above,

called microinjection. The new DNA is injected directly into a fertilised egg cell before it

starts dividing. It is a random process and only rarely is the DNA incorporated into the cell

DNA.

Once an embryo has been genetically altered, it is implanted into the uterus of a surrogate

mother. The resulting transgenic animal can be used to breed by traditional methods, with

each offspring containing the altered gene. The first transgenic animal was produced in this

manner in 1981 when a rabbit gene was inserted into a mouse embryo.

There are four main reasons for producing transgenic animals. These are:

• as disease models for medical research eg. OncoMouse® (See below.)

• for genetic research

• to produce drugs

• for organ donation.

Examples of GM species

Genetically modified (GM) species are those that have genes from another species inserted

into their DNA by genetic engineering. Because the genes of all living things use the same

DNA code (with a couple of unusual exceptions), the genes from any organism can be

inserted into any other organism.

Although genetic engineering is a very young field, it has already had some impact on food

production and promises to have much more in the future. For example, about half the cheese

produced in the United States uses an enzyme created by bacteria that have been genetically

engineered to contain a cow gene.

Extensive research is under way by firms such as Calgene, Monsanto and DuPont to

genetically engineer crops that are resistant to herbicides, harmful insects, viruses, bacteria

and fungi.

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Genetic manipulations at the level of DNA have also changed long held views as to what is

considered to be animal, plant and human. For example, how do you classify a plant that

contains animal genes and makes animal proteins? There are growing concerns about the

future applications of GM technology and how it may adversely affect environments, our

health and lifestyles.

The potential impact that gene technology will have on the diversity of species has recently

sparked a lot of debate.

As you read the GM examples below, think about advantages and

disadvantages of transgenic species. Discuss your ideas and opinions with

other people, if you can.

Bt cotton

Bt cotton has been genetically engineered to produce a natural insecticide that comes from a

common soil bacterium, Baccilus thuringiensis (thus Bt). By using this type of cotton, that

produces its own insecticide to kill insect pests, farmers spend much less on pesticides and the

environment is protected as well.

The toxin made using the Bt gene is also environmentally friendly because it kills only

Heliothis (a caterpillar species) and closely related species.

Canola

All over the world, Canola is grown for food oil. It is a preferred species for biotechnology

because it is easy to introduce genes into it using Agrobacterium and it can be propagated

from one cell (micropropagation). In Canada, transgenic canola oil is produced from

herbicide resistant plants. There are many other trials to develop new products using

transgenic canola.

OncoMouse®

OncoMouse® have been developed to be used in cancer research. These mice have been

genetically engineered to always develop breast and lymph cancer and die of these human

cancers within 90 days. They are used worldwide to test new cancer drugs and therapies.

Polly the sheep

Polly is a transgenic sheep. She has been engineered to produce a human protein that makes

blood clot. This will be useful for haemophiliacs. The idea is that the sheep’s milk will

contain the clotting factor and this can be harvested.

Xenotransplantation

Xenotransplantation is the use of other species for organ transplants (animal to human

transplants). Transgenic pigs have been developed to possess the gene that codes for human

cell-surface protein. Normally, if you introduce a pig organ into a human, the body would

reject it. However, if the surface of the organ has a coating of human protein then rejection

may be prevented.

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Consider the example of the OncoMouse®.

1 In what way(s) is the development and use of the OncoMouse® a

good thing?

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2 In what way(s) is its development and use a bad thing?

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Check your answers.

Now it’s your turn to research some transgenic species. Use the examples

given or other examples, such as transgenic tomatoes, to identify three

transgenic species. Present arguments for and against the use of these

transgenic species.

There are some Internet addresses for you to start with on the LMPC

Science webpage at:


Once you have completed your research, do Exercise 5.2.

When crop plants such as Canola, rice and BT-cotton are grown the plants are genetically

identical. As these crops have commercial advantages there are grown throughout the world.

This means that there is a reduction in genetic diversity. Instead of growing many varieties of

crops there is only one. If there is a disaster such as a new disease the whole of the crop will

be wiped out, leading to starvation.

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Genetics and ethics

Scrupulous members of society have principles and beliefs. Ethics are the result of informed

debate among these members of our community.

Early in 1997, Dolly the sheep was cloned from the single cell of an adult sheep. The

researchers who did this are at the Roslin Institute in Scotland, a team led by Dr Ian Wilmut.

Dolly is an identical genetic copy of the individual animal from which she was cloned. She

is the first mammal in recorded history to be asexually reproduced.

Over the intervening months, the excitement in the popular press about Dolly has naturally

died down. But the ethical and philosophical issues that cloning mammals raise are still

there, and are of importance to society. As citizens and as civilised people we should all be

thinking about them.’

From an interview between Robyn Williams and Dr David Turner (Senior Lecturer in the Department

of Medicine at Flinders University).

As you can see from the above extract, there are many social, economic, philosophical and

ethical reasons that will arise as genetic engineering continues. The science of genetics is

proceeding at a greater rate that society can come to grips with.

In the Additional Resources section of this part there are two articles that

deal with some of the problems that are arising out of the new technologies.

Read these now. As you read, highlight or underline the problems that are

mentioned. Add your own thoughts in the margin.

Now think more carefully about the articles you have just read. The viewpoints in them have

been presented in different ways. How do you use information in these articles to help you to

make decisions about whether genetic engineering should occur?

Facts from fiction

You need to develop skills in assessing articles and judging whether information has been

presented accurately and in a balanced way. Many articles contain information that has been

selected and used to present one viewpoint rather than a discussion of alternate views.

What is the viewpoint of the writer of the first article about cotton?

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What are the viewpoints raised in the second article about pigs?

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Now look at the information included in each article. Both articles use quotations from

experts to support their argument. But has the information been tested in a scientific way?

Which article do you think uses more scientific evidence? (Which evidence would be easier to

test to check the viewpoint and conclusions of the article?)

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Your decision helps you to decide which article to believe more.

Of course, you would not make a decision about genetic engineering based on these two

articles only. You need to consider more evidence (and go on examining evidence) about this

important scientific and social issue.

There is more information in the Additional resources on unnumbered pages from a federal

agency called Biotechnology Australia. These fact sheets give you additional information

about the arguments in favour of and against genetic engineering. Read through the debate

now.

Then read and consider the following situations involving genetics and ethics – GM food, and

the Human Genome Project and gene therapy.

GM products and labelling

The introduction of genetically modified foods continues to give rise to debate. Many foods

contain genetically modified species. Do these products need to be labelled as genetically

modified?

Some arguments against genetic modification of food

• Are they safe to eat?

• Do they have same nutritional value?

• Will they lead to a loss of biodiversity?

• The consequences of changing genes between species have not been fully studied.

• Cross-pollination could introduce the genes to the wild population with unknown

consequences.

• People with allergies could eat food not knowing that the food contains genes from

another species.

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• Large companies could develop crops that could control the supply of food.

• New diseases may be created by modifying viral genes.

Arguments for genetic modification of food

• These techniques will produce more food to feed starving people around the world.

• Fewer pesticides and herbicides need to be used, which is better for the environment and

for farm workers’ health.

• Vaccines could be delivered through food.

• Vegetables can be modified to survive transport better.

• Australia’s soils are degraded; plants could be modified to grow in these soils.

What is your opinion about genetic modification of food?

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Now complete Exercise 5.3.

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Additional resources

Thailand: Government passes up pest free cotton

BANGKOK, (Dec. 3) IPS – At first, the prospect of having a high-yielding cotton plant that

needed no pesticides led to rosy projections of bumper crops and profits for farmers who

grow it.

But Thais will not be seeing hundreds of thousands of hectares planted to Bollgard cotton in

the country anytime soon, after fears were raised that the genetically altered plant may wreak

environmental havoc and put consumers of Thai traditional medicine at risk.

Last month, the Thai government announced it was calling off safety and effectiveness tests

on Bollgard cotton, developed by the U.S.-based chemical company Monsanto. The tests,

which began three years ago, were already nearing completion when Bangkok issued the

statement.

Bollgard cotton is also known as Bt cotton because it comes from plants inserted with

Bacillus thuringiensis (Bt), which kills off pests. Cotton is among the world’s cash crops

hardest hit by pests. But activists here say there is no guarantee that Bt would not spread to

other plants belonging to the same species as Bollgard cotton and kill insects in wider areas of

the country.

Makers of Thai herbal medicine, in which cotton is an essential ingredient, also raised

concerns about the effect of using medicines with Bt cotton. The Institute of Traditional Thai

Medicine says 16 species of the “Malvacaea” cotton family are used in the production of

traditional health remedies.

According to Witoon Liancharoon of the Alternative Agriculture Network Thailand, Bt cotton

is already being grown commercially in the United States and Australia. But this is done only

in restricted areas. That would not have been the case in Thailand, if plans had pushed through.

Witoon notes, for instance, that the plan was to market the seeds to agriculturists throughout

the country. Some 485,000 hectares of land were to be set aside as cotton-growing areas.

Witoon says the tests here should have been conducted differently from those in the U.S. and

Australia, because tropical Thailand obviously has different biodiversity conditions. He adds

the tests should have looked into possible risks if someone takes herbal medicine made with

Bt cotton.

“As far as I know,” Witoon said, “the tests that have been done focused only on impacts on

useful insects in the areas and the economic potential of growing (Bt) cotton.”


Dr. Pennapa Subcharoen, director of the Institute of Traditional Thai Medicine, says the

Bollgard cotton tests records show that some 30 percent of the bee population in the test sites

died. However, she told a local newspaper, no further assessment was made to determine if

the Bt cotton was linked to the death of the bees.

The doctor says a sufficient assessment of Bt cotton is needed before it can be grown locally

in a larger scale. The Bt cotton tests are considered Thailand’s first genetic engineering

experiment in mass production.

Though protests forced the government to rethink the Bollgard cotton project, Witoon says

that does not mean Thailand has heard the last of such ventures. The country has no laws that

help protect its biodiversity, he says.

“Genetic engineering is something beyond the understanding of most Thai agriculturists,” he

observed.

“It is easy to make them welcome anything that gives quick positive results without knowing

of the much more negative impacts that may follow. If the cotton could help them kill insects

without spending money on insecticides, they would think this cotton is perfect and the seeds

would sell out for sure,” he added.

Witoon says this foolhardiness among many Thai agriculturists makes the need for a

“biosafety law” urgent. “They have no idea what could happen in the future,” he said.

Meanwhile, Witoon’s group and the Thai Network on Community Rights and Genetic

Resources are using existing laws in their bid to change the composition of the cotton testing

board.

Under the new Constitution, government bodies are not allowed to have appointees whose

involvement with other groups or private businesses may result in a conflict of interest.

At present, the cotton testing board has three representatives of Monsanto as members. If the

board’s composition is not altered, no-government groups here say they are ready to sue the

agricultural ministry.

OTC 05.12.97 03:06.

From http://eagle.westnet.gr/~cgian/thaicott.htm on 10 April, 2001.

Human-pig embryo accusation provokes debate

Two firms seeking a patent on an embryo cloning process have denied accusations by

Greenpeace that they are creating “human-pig” hybrid embryos, as the debate over

‘therapeutic cloning’ continues.

Reuters reports that according to Greenpeace Germany, the European Patent Office in Munich

has received a patent application (No: WO99/21415) US-based BioTransplant Inc. and

Australian firm Stem Cell Sciences which allows for the production of human/animal

embryos.

“The application shows that the firms have already transferred cell nuclei from human

foetuses to egg cells from pigs and cultivated the resulting embryos for around a week in the

laboratory,” Greenpeace said in a statement.

“Society should not reward these Frankenstein scientists with patents,” it added. A US

spokeswoman for the companies involved in the patent application confirmed that laboratory

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cells of human origin had been used in the experiment but denied that what resulted was a

human hybrid, and said Greenpeace had misunderstood the case.

“The source of the cell was a laboratory cell line of human origin. It was an aneuploid cell,

which means it was totally incapable of creating a human being. It was experimentally

impossible to create a hybrid pig-human organism,” Patricia Dimond told Reuters. Chief

executive officer of Melbourne-based Stem Cell Sciences, Peter Mountford told Reuters that

his company had indeed put a human cell nucleus into a pig’s egg. This nuclear transfer

method involves scraping the nucleus out of an egg cell and replacing it with the nucleus,

which contains most of the genetic material, from another cell. The process, if done correctly,

re-programs the nucleus and it starts to divide as if it were a fertilised egg. In effect, it

regresses back to the very first stages of life.

These cell masses could be a source of embryonic stem cells, which have the power to

become any type of cell in the body at all, including nerve cells, blood cells or organ cells.

Stem Cell Sciences said it had shown last month that this could be done, using mice.

The same technique was used to create Dolly the sheep, the first cloned adult mammal

however in this latest case, Stem Cell Sciences, working with a team at Monash University,

has used a pig’s egg cell and the nucleus from a human cell. After the nuclear transfer the

cells divided, 4 or 5 times, to create a mass of either 16 or 32 cells. Mountford said the

experiment proved that human and animal cells could be fused for the purpose of therapeutic

cloning.

A matter of definition. The researchers expressed aim is to find alternatives to organ

donation, however as to whether they are making human/pig hybrid embryos, it seems to be a

matter of semantics.

The application clearly asks for permission to patent a process enabling the transfer of a

nucleus from one species into another species and the production of a transgenic embryo, and

there does not appear to be any restriction on whether the donor or recipient cell is human

science legal expert Dr Dianne Nicol from the University of Tasmania told ABC Science

Online.

“It depends on what you define as a human embryo. Is it the cytoplasm or the nucleus

containing the human genes.”

Another company has done similar work. In 1998, Advanced Cell Technology, based in

Worcester, Massachusetts, said its scientists had fused human cells into cow eggs and let them

grow as an embryo for a few days. Its aim is also to produce organs and tissues for transplant.

The reason researchers use cow or pig eggs is that they are more readily available than human

eggs, which can be obtained only through difficult and painful surgery. Farm animal eggs are

available at any slaughterhouse.

BioTransplant Inc. is also working on genetically engineered pigs as a potential source of

animal-to-human transplants, or xenotransplants. Animals containing human genes, known as

chimeras, are commonly used in medical science -- for instance, sheep that produce human

proteins in their milk.

The US government is forbidden by law to fund scientists who engage in cloning, therapeutic

or otherwise, but privately funded scientists can legally do as they please.

Britain’s chief scientific officer has proposed that therapeutic cloning be legalised there, but

the European Parliament condemned the idea in September. Australia is debating the issue.


From ABC on-line, Monday, 9 October 2000

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Suggested answers

Artificial selection

Artificial selection is deliberating mating organisms that have the desired features. Humans

have been doing this ever since they domesticated animals and plants. It creates changes in a

species and provides evidence for natural selection.

Artificial insemination

The genetic material from one bull would be passed on and this would lead to a reduction in

genetic diversity.

In vitro fertilisation

People unable to produce offspring naturally may pass on infertility genes to the next

generation.

Artificial pollination

Plant breeders choose desirable qualities for the plants that they produce but once again they

reduce the genetic diversity. This may lead to problems if new pests are encountered.

Examples of GM species1 The OncoMouse

® allows scientists to test new drugs for cancer treatment. This helps

cancer sufferers and may lead to a cure for cancer.

2 Is it ethical to breed an animal so that it will die from cancer?


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Exercises – Part 5

Exercises 5.1 to 5.3 Name: _________________________________

Exercise 5.1: Artificial selectiona) Today, the methods used to artificially select organisms have advanced greatly. Describe

each of the following breeding techniques and suggest how each may alter the genetic

composition of a population.

i artificial insemination

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ii artificial pollination

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iii cloning

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b) Scientists from the Australian Museum of Natural History want to revive the Thylacine (a

type of marsupial dog) which is thought to be extinct.


The Thylacine – should we clone this animal?

Many years ago, a Thylacine pup was preserved in alcohol (which does not destroy

DNA). From what you now understand about cloning, could it be possible to recreate a

Thylacine today and should this type of research be carried out?

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Exercise 5.2: Transgenic speciesa) Name three transgenic species that you have researched. Give a brief description of each.

Example 1

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Example 2

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Example 3

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b) List three ways that transgenic species can be produced, and outline each method.

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c) What are three reasons that transgenic species have been produced and are being used?

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Exercise 5.3: Genetics and ethicsa) Do you think that the development and use of transgenic species is a good idea? Include

at least two reasons to support your opinion in your answer.

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b) If someone disagreed with your opinion, what are two reasons that would be given to

refute your argument?

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c) Name a genetically modified plant and a genetically modified animal. Use these

examples to discuss some possible impacts of genetic engineering and reproductive

technologies (artificial insemination, artificial pollination and cloning) on genetic

diversity.

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