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Chapter 7 Animal Biotechnology

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Title: Chapter 7 Animal Biotechnology


1
Chapter 7 Animal Biotechnology
BTEC 3301
2
Dolly the sheep
  • Dolly was created by agricultural research
    scientists, who were being funded to make the
    perfect sheep, for the purposes of more efficient
    agricultural production.
  • The name "Dolly" came from a suggestion by the
    stockmen who helped in the process, in honor of
    Dolly Parton, because the cloned cell was a
    mammary cell
  • After the cloning was successfully demonstrated
    by Dolly creators, many other large mammals have
    been cloned, including horses and bulls.

3
  • Dolly who became the first famous adult cloned
    sheep was successfully cloned in 1996, (July 1996
    to Feb 2003) was the first mammal to have been
    successfully cloned from adult cells.
  • She was created at Roslin Institute Scotland and
    lived there until her death nearly seven years
    later.
  • Dolly was put down on
  • Feb 14 2003, due to complications from a lung
    infection.
  • Refer Pg 159 Fig7.7 for the process.

4
Transgenic Animals
  • Animal biotechnology is the field to engineer
    transgenic animals, i.e., animals that carry
    genes from other species.
  • The technology has already produced transgenic
    animals such as mice, rats, rabbits, pigs, sheep,
    and cows

5
What is a transgenic animal?
  • A transgenic animal is one whose genome has been
    changed to carry genes from other species.
  • For example, an embryo can have an extra,
    functioning gene from another source artificially
    introduced into it, or a gene introduced which
    can knock out the functioning of another
    particular gene in the embryo

6
  • Animals that have their DNA manipulated in this
    way are known as transgenic animals.
  • Transgenic animals are useful as disease models
    and producers of substances for human welfare

7
Why are these animals being produced?
  • Some transgenic animals are produced for specific
    economic traits. For example, transgenic cattle
    were created to produce milk containing
    particular human proteins, which may help in the
    treatment of human emphysema (A lung disease
    which involves damage to the air sacs (alveoli)
    in the lungs)

8
  • Other transgenic animals are produced as disease
    models (animals genetically manipulated to
    exhibit disease symptoms so that effective
    treatment can be studied
  • The OncoMouse or the Harvard mouse, carrying a
    gene that promotes the development of various
    human cancers

9
How are transgenic animals produced?
  • DNA microinjection
  • Introducing the transgene DNA directly into the
    zygote at an early stage of development. No
    vector required
  • Retrovirus-mediated gene transfer
  • Infecting mouse embryo with a retrovirus which
    carry the new gene. Using virus as a vector .

10
  • Embryonic stem cell-mediated gene transfer
  • The blastocyst (inner layer of a fertilized egg)
    is harvested and mixed with recombinant DNA and
    inserted back in the blastocyst
  • Sperm-mediated transfer
  • Use of Linker protein" to attach DNA to sperm
    which transfer the new DNA during fertilization.
  • Gene gun
  • As described in Chapter 6.

11
Embryonic stem cell-mediated gene transfer
  • This method involves
  • isolation of totipotent stem cells (stem cells
    that can develop into any type of specialized
    cell) from embryos
  • the desired gene is inserted into these cells
  • Cells containing the desired DNA are incorporated
    into the host's embryo.

12
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13
Assignment for class Stem cell Research.
  • Stem cell Research

14
Improving Agricultural Products with Transgenics
  • Transgenic technology holds great potential in
    agriculture, medicine, and industry
  • The benefits of these animals to human welfare
    can be grouped into areas
  • Agriculture
  • Medicine
  • Industry

15
1. Agricultural Applications
  • A) Breeding
  • Traditional cross breeding have been used for
    ages to create chickens, cows, pigs etc.
  • Farmers have always used selective breeding to
    produce animals that exhibit desired traits
    (e.g., increased milk production, high growth
    rate).
  • Traditional breeding is a time-consuming,
    difficult task.

16
  • Researchers have now used gene transfer to
    improve the productivity of livestock. Now it is
    possible to develop traits in animals in a
    shorter time and with more precision.
  • It also offers farmers an easy way to increase
    yields.

17
  • Scientists can improve the size of livestock
    genetically.
  • Transgenic cows exist that produce more milk or
    milk with less lactose or cholesterol.
  • Transgenic cows have been used to produce milk
    which are richer in proteins and lower in fat.

18
  • B) Quality
  • Herman, a transgenic bull carries a human gene
    for Lactoferrin (gene responsible for higher iron
    content)
  • Pigs and cattle that have more meat on them.
  • Sheep that grow more wool.
  • Eggs can be made healthier with high quality
    protein.

19
  • C) Disease resistance
  • Disease-resistant livestock is not a reality just
    yet.
  • But there has been improvement in disease
    reduction in animals.
  • The Foot- and- Mouth disease in England in 2000
    led to destruction of herds of cattle, sheep and
    goat.

20
  • Scientists are attempting to produce
    disease-resistant animals, such as
    influenza-resistant pigs, but a very limited
    number of genes are currently known to be
    responsible for resistance to diseases in farm
    animals.
  • Transgenic disease protection promises a long
    term cost effective method of battling animal
    diseases.

21
2. Medical Applications
  • Xenotransplantation
  • Transplant organs may soon come from transgenic
    animals.
  • Transgenic pigs may provide the transplant organs
    needed to alleviate the shortage of organs donor

22
  • Xenotransplantation is hampered by a pig protein
    that can cause donor rejection but research is
    underway to remove the pig protein and replace it
    with a human protein.
  • Milk-producing transgenic animals are especially
    useful for medicines.

23
  • B) Nutritional supplements and pharmaceuticals
  • Products such as insulin, growth hormone, and
    blood anti-clotting factors may soon be or have
    already been obtained from the milk of transgenic
    cows, sheep, or goats.
  • The first transgenic cow (Rosie ) produced human
    protein-enriched milk at 2.4 grams per liter.

24
  • This transgenic milk is a more nutritionally
    balanced product than natural milk and could be
    given to babies or the elderly with special
    nutritional or digestive needs.
  • A transgenic cow exists that produces a substance
    to help human red cells grow.

25
  • C) Human gene therapy
  • Human gene therapy involves adding a normal copy
    of a gene (transgene) to the genome of a person
    carrying defective copies of the gene.
  • Finland produced a calf with a gene that makes
    the substance that promotes the growth of red
    cells in humans.

26
3. Industrial Applications
  • By extracting polymer strands from the milk and
    weaving them into thread, the scientists can
    create a light, tough, flexible material that
    could be used in such applications as military
    uniforms, medical microsutures, and tennis racket
    strings.
  • Biosteel is an extraordinary new product that may
    be soon used in bullet proof vests and in suture
    silk for stitching wounds.
  • Animals have been used as Bioreactors to
    produce proteins. Genes for desired proteins are
    introduced via transgenics to the target cells .

27
  • The target cells are cloned and several such
    cells are raised into adults.
  • These adults may produce milk or eggs (due to the
    presence of introduced gene rich in desired
    protein).
  • Toxicity-sensitive transgenic animals have been
    produced for chemical safety testing.
  • Microorganisms have been engineered to produce a
    wide variety of proteins, which in turn can
    produce enzymes that can speed up industrial
    chemical reactions.

28
  • Transgenic animals have been used to produce
    pharmaceutical protein example a human gene
    called AT III has been transferred to goats.
  • Goats milk contain this protein that prevents
    blood clotting (goats multiply faster than cows)
  • Hen bioreactor eggs are used to enrich protein
    by recombinant DNA technology.

29
What are the ethical concerns surrounding
transgenesis?
  • Ethical concern is ever increasing as the
    technology grows, including the issue of lab
    animal welfare
  • These ethical issues include questions such as
  • Should there be universal protocols for
    transgenesis?
  • Should such protocols demand that only the most
    promising research be permitted?

30
  • Is human welfare the only consideration?
  • What about the welfare of other life forms?
  • Should scientists focus on in vitro (cultured in
    a lab) transgenic methods rather than, or before,
    using live animals to alleviate animal suffering?

31
?
  • Will transgenic animals radically change the
    direction of evolution, which may result in
    drastic consequences for nature and humans alike?
  • Should patents be allowed on transgenic animals,
    which may hamper the free exchange of scientific
    research? ?

32
A summary of Animal Cloning
  • Although there has been limited success in
    cloning some animals, it's still seen as a viable
    technology.
  • Ever since the announcement of the birth of Dolly
    three years ago, additional sheep, cows, goats,
    pigs and mice have been cloned.
  • So far, most cloned animals die just before or
    after birth.

33
  • There are still obvious problems as evidenced
    from the numerous deaths of cloned animals that
    occur just before or after birth.
  • Cloning is a big first step. Genetic manipulation
    of cloned animals is the future direction of the
    cloning frontier.

34
  • Cloning can produce genetically identical
    laboratory animals which can be used as models
    for human disease.
  • No live dog clones have yet been reported, the
    company PerPETuate, Inc. (Connecticut) is
    freezing tissue from family pets for the future.
  • Cells could be harvested from early embryos to
    provide cell and tissue replacement without the
    hazards of transplantation rejection.

35
  • The cloning of human embryos for reproductive
    purposes is illegal at this time.
  • Yet it is still important to examine the
    consequences and the likelihood of this scenario.
  • The media may dream up and forecast robotic
    cloned armies of Hitler however, identical twins
    illustrate that being genetically identical does
    not remove their humanness.

36
  • At any rate, there have been significant
    difficulties with cloning primates, including an
    extremely low success rate and a high number of
    abnormalities.
  • These results make it unacceptable to attempt
    human cloning at this moment in time.
  • Cloning has opened many doors that could lead to
    remarkable medical advancements but, as with all
    new technologies, it will be accompanied by
    ethical and social dilemmas.

37
  • Today's successes will pave the road to improving
    efficiencies and help add to the basic
    understanding of our cells.
  • Even Dolly's creator, Ian Wilmut, is focusing
    less on sheep and more on understanding the
    mechanism of reprogramming our genetic material!.

38
What are stem cells?
  • Additional reading
  • Keep update with political issues on stem cells
    research including Christopher Reeves (Superman)
    idea of promoting stem cell research.

39
  • Stem cells can be used to grow any organ.
  • Stem cells have the capacity to develop into any
    type of cell in the body.
  • And therefore, they have the potential to be used
    for almost anything, organ transplants, a cure
    for Parkinson's etc.
  • Fetal stem cells, once harvested, cannot become
    embryos!.

40
  • When a woman's egg is fertilized, the egg (or
    zygote) is totipotent -- it has the capacity to
    turn into any type of cell in the human body,
    including the placenta.
  • About four days after fertilization the cells
    begin to specialize and form a blastocyst, which
    is a hollow sphere of cells with an inner cell
    mass in the center.
  • The outer layer of cells becomes the placenta and
    other tissues necessary for the survival of the
    fetus

41
  • The inner cell mass goes on to form the fetus and
    eventually the baby. It is these inner cells that
    are so incredible because they go on to form all
    the tissues in the human body.
  • If this inner cell mass was placed in a woman's
    uterus, it would not develop into a fetus and
    because of this some people claim that this
    cannot be considered an embryo

42
  • The controversy comes when the cells are
    harvested.
  • Harvesting can be done by
  • obtaining cells from the embryos of terminated
    pregnancies
  • getting them from embryos from in vitro
    fertilization clinics

43
The politics of stem cells
  • In 1993, President Clinton banned federally
    funded research on stem cells and now President
    Bush has promised that he'll "not support
    research from aborted fetuses."
  • The government's position reflects the views by
    others who oppose stem cell research. For
    example

44
  • Religious groups and some politicians believe
    that it's unethical to harvest these cells
    because they believe it destroys the embryo.
  • One Kansas senator went as far as to say that
    it's "Nazism," saying it's "illegal, immoral, and
    unnecessary."3

45
  • Some religious groups also believe that "you are
    getting in the way of God's work.
  • Adult stem cells have limited potential and may
    carry genetic mutations

46
Animal Biotechnology
  • Dolly

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References
  • http//www.animalbiotechnology.org/ani_bio.asp
    (List of transgenic animals)
  • http//en.wikipedia.org/wiki/Human_cloning (Human
    cloning)
  • http//www.gre.ac.uk/courses/under/sch/cls/biochem
    _bsc.html (Cloning)
  • http//www.stemcells.ca/
  • http//en.wikipedia.org/wiki/Stem_cell
  • http//gslc.genetics.utah.edu/units/stemcells/
  • http//www.humancloning.org/dolly.htm (Dolly
    created)
  • http//news.bbc.co.uk/2/hi/science/nature/2764039.
    stm (Dolly dies)
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