Transgenic AnimalsExtended Response Task 2 – Semester 4 2010

James Dunn8/20/2010

Gene technology is a tool that uses the living things to make or change products. Gene technology sits within the area of Bio-Technology. Biotechnology, traditionally, has been used to produce products we eat today, these include: baking bread, making cheese and brewing beer. As gene technology develops, modern biotechnology includes the discovery of “genes, understanding gene function and interactions and the use of DNA markers and gene technology (CSIRO, 2009)”.

A gene, in definition, is basically a reflection of DNA that codes for a protein. Each gene differentiates as it possesses a unique sequence of bases that code for the production of a unique protein. Through these proteins and combinations, each gives a unique phenotype. Gene technology can be used for many things, the concept outline consists of: Having “the ability to manipulate DNA that leads to new genetics” (Dr. George Johnson, 1998-2008), Genetic Engineering and Bio Technology. The main focus on today will cover the process of Transgenic Animals.

“A transgenic animal is one that carries a foreign gene that has deliberately inserted into its genome. The foreign gene is constructed using recombinant DNA methodology. The DNA usually includes other sequences to enable it (Kimball’s Biology Pages, 2009)”. Through this, it allows the foreign gene to incorporate itself into the DNA structure of the host which then allows it to be expressed correctly into the cells of the host. Three examples of successfully cloned animals, these being sheep, goats and chickens, have both been cloned for a specific benefit towards their own products. Transgenic sheep have been were produced to articulate foreign proteins in their milk (Refer to Fig 3 Appendices for information on how a transgenic sheep is produced). Transgenic chickens are now capable of synthesizing human proteins into “white” of their produced eggs. Each of these animals proves to be valuable resources towards the extract of proteins for human therapy.

A common example which has thoroughly been tested has been on the species of mice. It is known that “transgenic mice have provided the tools for many biological question (Kimball’s Biology Pages, 2009)”. The example consists of the experiment that normal mice cannot be infected by the polio virus. This is due to lacking the cell-surface mole that, in relation to humans; serve as a receptor for the virus. This puts forward a representation that normal mice cannot be used for the study of the disease but instead, transgenic mice can be used for the study as they possess a human gene so they can act as receptor for the polio virus. This can cause transgenic mice to become infected by the polio virus and possibly developing paralysis and other pathological disease that human can be infected by.

There are two methods of producing transgenic mice, these are called: The Embryonic Stem Cell Method and The Pronucleus Method (refer to Fig 1 for the ES Cell Method and Fig 2 for The Pronucleus Method also Step by Step Methods)

There has been a large debate over whether Transgenic Animals are anything but beneficial or create risks for our environment. These benefits or risks relate around the ethical, social and economical factors. Ethical benefits play a huge role in the acceptance of breeding transgenic animals and using their traits to sustain our daily needs. There are three applications that transgenic animals would benefit towards these being: Agriculture, Medicine and Industry.

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Each application has its own sub-division which sorts the beneficial parts towards the application.

Breeding for the agricultural application allows farmers to always use “selected breeding procedures to

produce animals that exhibit desired traits” (e.g. increased milk production and high growth rate

(American Institute of Biological Science, 2000-2010). This allows transgenises to allow larger herds to

produce specific desired traits. When molecular biology and its usage were developed, it evidently

became possible for animals to develop a more precision trait in a shortened amount of time. This in

relation is compared to the traditional breeding process which was difficult and was time-consuming.

This meant that it took longer for animals to develop a specific trait.

The quality of specific traits has been questioned overtime, and it is said that “scientists can improve the

size of livestock genetically” (American Institute of Biological Science, 2000-2010). This means that with

reference to the traits produced by the genetically modified animal, the farmer developed and used a

particular growth hormone which spurred the development of the animals. This technique was only

seen to be problematic as the hormones remained inside the specific animal trait.

Transgenic animals not only help with their specific traits, but their internal organs, can merely in the

future save humans lives. This is due to 5000 patients around the world needing hearts, livers and

kidneys each year (American Institute of Biological Science, 2000-2010). Xenotransplantation is the

transplantation of foreign living cells, tissues or organs from one species to several others. A pig’s organs

soon can be transplanted into a human once is it finished being hampered by pig proteins. Currently,

this causes a donor rejection due to the different proteins. Researchers are currently looking for a

method on how to change the pig proteins to humans.

In relation to transgenises researchers are undertaking possibilities on ways to discover how the milk

produced by transgenic cows, sheep or goats can treat diseases such as “hereditary emphysema, PKU

(phenylketonuria) and cystic fibrosis” (American Institute of Biological Science, 2000-2010). Rosie, the

first produced transgenic cow, produced human protein enriched milk at 2.4g per litre. The milk was

more nutrionally balanced than original milk from cows and could be given to the elderly or babies with

the correct digestive system needs. Rosie’s milk contained the human gene of alpha-lactalbumin.

Along with Rosie producing her milk, this arose the potential it could have serving as proper milk

to eat and drink. This reflected on other benefits relating to transgenic animals.

Many other ethical and economic benefits including: Increased growth rates, Improved disease

resistance, Improved food-conversion rates, Leaner meat, Increased muscle mass, Improved wool

quality, all have been environmentally tested to reduce and potential risks. Even though transgenic

animals in general seem a good thing to be brought into society, but they’re overwhelming if looking to

purchase an animal. The costs are substantially high and customers or consumers might feel that it

would be unnecessary to be charged that much (refer to fig 4 appendices).

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A lot of controversy has been made over the fact that in relation to the benefits of transgenic animals,

there are risks too (e.g. disease resistant). Disease resistant animals has been have been a temptation

for scientists to produce disease-free animals. Animals such as pigs: carry the influenza virus as they

possess a human gene inside of them which makes them a host for human-like disease (also called

receptor). At this moment in time “disease resistant livestock, is not a reality just yet” (American

Institute of Biological Science, 2000-2010). There are very limited amount of genes that are currently

known to be held responsible for any resistance towards any diseases hosted by farm animals.

With producing disease-free animals, many arguments have been made regards to the cross species.

The risks in relation to xenotransplantation, is unclear as there are known risks involved with the

transplant. Disease such as: Zoonotic diseases, such as “spongiform encephalopathy” (also known as

“mad cow disease”). The “mad cow” disease is small but hosts a significant risk of broadcasting.

Xenotransplantation has been banned from the U.S Food and Drug Administrators as trails are being

held using non-human primates until the procedure has been formerly finished. Once finished it must be

then demonstrated again to be safe with regards to the ethical, social and economical issues.

Transgenic animals mightn’t just be a good thing, but there are risks involved with introducing and

producing these species into our world. These are views of not only the public but also religious views as

well. Religious ethical issues state that Transgenic Animals and their produced are playing the “role of

god” and “manipulating nature” (Mohbon, 2007). With relation to the ethical issues, the social issues are

looked upon and many consumers of the public are wondering about their consumer safety. Many of

the society see nothing but to boycott the transgenic products as they’d simply prefer to buy products

from the traditional breeding animals. This put many views from society at stake.

Social views from the religious public state that “crossing species boundaries are unnatural,

immoral, and in violation of God’s laws” (American Institute of Biological Science, 2000-2010). This

put forwards arguments that these “special boundaries” are readily delineated and fixed. Recent

issues discovered through the “American Journal of Bioethics” states that the species boundaries

are a widely disputed topic. It points out that some bioethicists pointed out the a variety of

different species (e.g. morphological, biological, ecological and evolutionary). All of these topics

in definition reflect on the changing theories of what species are used through varying purposes

towards individual humans.

There are other multiple risks involved with transgenic animals as there is potential harm in human

transplantation, environmental risks (depopulation against natural native species, mixing of natural and

transgenic animals), increase in allergies, risks in evolution, alterations involved with the food chains and

religious groups don’t agree with transgenic animals as they’re going against the will god.

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There are advantages and disadvantages with regards to Transgenic Animals. This is because Transgenic

Animal can do wonderful things but may cause harm to native animals and the society. You could say

that there is more benefits towards Transgenic Animals, as in the future, a hybrid type animal will

produce multiple traits that can be used across the human population. Currently, pigs, chickens, cows,

sheep and goats produce specific traits in order to fulfill the desire we need to operate throughout our

daily basis.

Each of the animals produce specific traits such as cows – their milk and meat, pigs also for their meat,

chickens their eggs (providing more human proteins in the “white” of their egg), sheep and goats also

for their milk (as it provides more enriched human proteins and their fur coats for specific furniture

needs). Every Transgenic Animal has a particular role as it has been produced, merely to provide for

human nature. With this there are also the disadvantages involved as well.

The religious and a sector of the public society have their different views on the social factor of

Transgenic Animals as it goes against God’s will and creation of “pure natural” animals or that they’d

simply rather have natural products for their intake. In conclusion, transgenic animals should only be

used for farming uses not for individual use as the cost to raise a Transgenic Animal costs a fortune.

There seems to be more benefits towards Transgenic Animals as most of the modern society see no

harm in producing the animals. Their specific traits offer and obtain the daily nutrients and proteins we

need to survive and that is on the main factors why Transgenic Animals are more beneficial than risky.

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Reference List

1. Kimball’s Biology Pages,2009, Transgenic Animals, Viewed 02 August 2010,http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/T/TransgenicAnimals.html

2. CSIRO, 2009, Gene Technology, Viewed 02 August 2010,http://www.csiro.au/science/Biotechnology.html

3. Dr. George Johnson, 1998-2008, Gene Technology Contents, Viewed 02 August 2010,http://txtwriter.com/Backgrounders/Genetech/GEcontents.html

4. American Institute of Biological Science, 2000-2010, Transgenic Animals and Their benefits to human welfare, Viewed 03 August 2010,http://www.actionbioscience.org/biotech/margawati.html

5. Mohbon, 2007, Transgenic Animals Ethical and Social Issues, Viewed 03 August 2010,http://mohnbon.webs.com/socialethicalissues.htm

6. BBC Ethics, 2010, Biotechnology, Animal Ethics – Biotechnology, Viewed 03 August 2010,http://www.bbc.co.uk/ethics/animals/using/biotechnology_1.shtml

7. American Institute of Biological Science, 2000-2010, Ethical Issues in Genetic Engineering, Viewed 04 August 2010,http://www.actionbioscience.org/biotech/glenn.html

8. Kimball’s Biology Pages,2008, Can Humans Be Cloned? Viewed 05 August 2010,http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/CloningMammals.html#why_not

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Appendices

The Embryonic Stem Cell Method 1

Fig 1 – Embryonic Stem Cell Method

Kimball’s Biology Pages,2009, Transgenic Animals, Viewed 02 August 2010,http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/T/TransgenicAnimals.html

1. Making your DNA!

Through DNA use, the molecules of DNA contain:

the structural gene you desire (e.g., the insulin gene) The DNA enables the molecule to be inserted into the host’s DNA molecules.

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The enhancer and promoter sequences enable the genes to be expressed from the host cells.

2. Transforming the Embryonic Cells (EC) into host

Through exposure, the cultured cells are taken by the DNA to be incorporated.

3. Select wisely for the transformed cells.

4. Inject the cells into the (ICM) Inner cell mass of the mouse blastocysts.

5. Embryo transfer

Involves preparing a pseudopregnant mouse. (Caused by a female mouse to mate with a vasectomised male).

“The stimulus of mating elicits the hormonal changes needed to make her uterus receptive. Transfer the embryos into her uterus” (Kimball’s Biology Pages,2009). With hope that the implant is successful, they should develop into healthy pups with a chance

that no more than one-third will.

6. Testing her offspring

Start off with removing a small piece of tissue from the tail. Then examine the DNA consumed from the gene. Approximately no more than 10-20% will have the heterozygous as a gene.

7. Establishing the transgenic gene

Mate two of the heterozygous mice, record their offspring so that 1:4 will be homozygous for the transgene.

Through this, the procedure of mating will have found the transgenic strain.

Kimball’s Biology Pages,2009, Transgenic Animals, Viewed 02 August 2010,http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/T/TransgenicAnimals.html

The Pronucleus Method 2

1. Prepare in the same way as Method 1.

2. Transformation of fertilized eggs

Harvest the fresh fertilized eggs before the sperm head has developed into the pronucleus. Inject the male pronucleus with the specific (your) DNA. “When the pronuclei have fused to form the diploid zygote nucleus, allow the zygote to divide

by mitosis to form a 2-cell embryo” (Kimball’s Biology Pages,2009).

3. Implant the embryos into the pseudopregnant foster mother and proceed in regards to Method 1

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Fig 2 – The Pronucleus Method – Represent two mice, left being a normal littermate mouse and right being a transgenic mouse.

Kimball’s Biology Pages,2009, Transgenic Animals, Viewed 02 August 2010,http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/T/TransgenicAnimals.html

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Fig 3 – Producing Transgenic Sheep(http://www.pharmainfo.net/files/images/stories/article_images/ProductionTransgenicAnimals.jpg )

Fig 4 – Price of a Transgenic Animal per year

(http://www.biotech.iastate.edu/biotech_info_series/images/552table01.gif).

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