Ethical Issues on Animal and Human cloning
Prof. P.C. Shaw (邵鵬柱教授 )Department of Biochemistry, CUHKHong Kong Bioethics Association
November 2009
複
製
人
?
History of cloning
1952 Northern leopard frogs cloned.
1953 S tructure of DNA discovered.
History of cloning 1978 Louise, the first child
conceived through in vitro fertilization, was born.
1993 Human embryos were first cloned (artificial embryo twinning)
July 5, 1996 Dolly was born.
Photo from: www.cnn.com
Dolly – the first mammal cloned using mature cell Dolly the Lamb
in 1996 Method: Nuclea
r transfer Organization: R
oslin Institute at UK and PPL Therapeutics
Photo from Ming Pao 18th August 2002
Example of cloning
Cumulina the Mouse in 1998
Organization: University of Hawaii
Photo from Ming Pao 28th December 2002
Example of cloning
Cattle in 1998
Organization: Kinki University at Japan
Photo from Ming Pao 28th December 2002
Example of cloning
Mille, Christa, Alexis, Carrel and Dotcom the Pigs in 2000
Organization: PPL Therapeutics of UK
Photo from Ming Pao 28th December 2002
Example of cloning
Carbon Copy the Cat in 2002
Organization: Texas A & M University, USA
Photo from Ming Pao 23th January 2003
Example of cloning Generation of
Prometea, 2003
Organization: A research laboratory in Italy
Photo from Nature No.6949
Examples of cloning Cloning of
donkey, 2004, USA
Cloning of dog, 2005, Korea
Cloning of rhesus monkey, 2007, Oregon, USA http://jamaica-gleaner.com/gleaner/20050806/mind/mind3.html
http://www.pbs.org/newshour/bb/science/july-dec07/stemcells_11-15.html
Two methods of cloning
Embryo cloning 胚胎複製 - remove a cell from an embryo for developing into a separate embryo.
Adult cell cloning 成長細胞複製 - replace DNA/nucleus from a cell by another.
Two methods of cloning
Embryo cloning 胚胎複製 – do not know the characteristics of the offspring.
Adult cell cloning 成長細胞複製 – characteristics are almost the same as the nucleus donor.
How to generate Dolly?
Step 1.
Udder ( 乳腺 ) cells were taken from a donor sheep. Cells were then cultured to switch off their genes and become dormant.
Photo from www.bootstrike.com, www.nature.com
How to generate Dolly?Step 2.
Unfertilized egg cell was taken from another sheep. The nucleus was removed, leaving an empty egg.
Photo from www.pbs.org. www.nature.com, www.sciam.com
How to generate Dolly?Step 3.
The egg cell without nucleus was fused with the donor cell using a pulse of electricity. A second pulse started the cell division.
Photo from www.advancedcell.com. www.nature.com
How to generate Dolly?
Step 4.
After 6 days, the resulting embryo was implanted into another sheep (surrogate mother 代母 ).
Photo from www.pbs.org, www.nature.com
How to generate Dolly?
Step 5.
After gestation ( 妊娠 ), the surrogate mother gave birth to Dolly which was identical to the udder cell donor.
Photo from www.pbs.org
Advantages of animal cloning
Can produce animal with a desired trait, for Protein products, organs
Proliferate endangered animals
Cloning of endangered animal
Noah the Gaur ( 亞洲野牛 , an endangered species) in 2000
Organization: Advanced Cell Technology, USA Photo from Advanced Cell Technology (www.advancedcell.c
om)
Cloning of endangered animal Cloning of
woolly Mammoth ( 長毛象 )
Extinct 10,000 years ago
Is there any intact cell left?
From Mingpao 8/8/2003
Cloning of transgenic animal
Cloning of a cow containing mad cow disease resistant gene
In Shangdong, China
From Mingpao 28/4/2006
Concerns in animal cloning Technology complicated Survival rate of cloned
embryos low Overweighing of calves at
birth Breeders may want to keep
their animal unique Breeders may want to
create better offspring
Health of clonesFrom Ming Pao 27-Mar-2001
• Poor development of heart, lung and immune system
• Might have genetic disorder
Photo from MingpaoPhoto from Mingpao
Dolly gave birth to a female lamb in
1998, but Dolly later died of premature
aging in 2003.
Company for cloning pets Genetic Savings & Clone – established in
2000, produced the cloned cat, CC in 2001 Delivered the first commercially cloned
cat, Little Nicky in 2004 for US$50,000 Company closed in 2006 A new company BioArts International was
established for cloning dogs
Commercial pet cloning may not be a good investment Demand not high Competition from developing countries
Disregard of the IP issues Relaxed treatment of animals
The IP holder does not want to defense the IP rights
Outcome is unpredicted – cloning is not a mature techniques
Pressure from the society
Cloning Human
Cloning – two kinds Reproductive cloning – an
embryo is created and implanted into a woman’s womb to bring it to term.
Therapeutic cloning – an embryo is created in order to obtain cells from it.
Why clone human? Just an ‘unconventional’ means of
reproduction In vitro fertilization Surrogate mother Adoption
Study human development
Produce spare parts Test for genetic defect Increase chance of
pregnancy Produce two children at
the same time
Why clone human?
Preserve traits and talents
Extension of life in unusual circumstances One spouse sterile Homosexual
marriage
Why clone human?
Cloned embryos provide : Brain cells for disorders like Par
kinson ( 柏金遜 ) and Alzheimer’s disease ( 老年痴呆症 )
Pancreatic islet cells for diabetes ( 糖尿 )
Positive points of therapeutic cloning
Cloned embryos provide : Nerve cells for spinal cord da
mage ( 脊椎受損 ) Blood and bone marrow cells
for blood cell disorder ( 血液疾病 )
Positive points of therapeutic cloning
http://dels.nas.edu/bls/stemcells/types-of-stem-cells.shtml
Embryonic stem cells Adult stem cells
The use of stem cells to generate clones
http://www.geneticsandsociety.org/article.php?id=257
1. Creating an embryo through in vitro fertilization,
2. culturing ES cells derived from it to provide a sufficient population for the tricky task of inserting genes
3. extracting the nucleus of a successfully altered cell to construct a cloned embryo
4. The resulting offspring would have developed from a cell derived from an embryo created with an egg and a sperm, and "improved" in the laboratory.
Why not perform reproductive cloning?
Eugenic ( 優生 ) – to maximize certain traits intentionally
Reduce genetic diversity Use as substitute for organ Clone may have reduced life expectancy Clone may be abnormal
Why not perform reproductive cloning?
Lack of self-identity Replaceable Dominated by the
‘father’ or ‘mother’
Why not perform reproductive cloning?
Upset traditional family relationship Twin of the cell
donor? Relationship with its
brother and sister Relationship with
spouse of the cell donor
Human Reproductive Technology Bill香港人類生殖科技條例 (2000)
Not allow the followings: Replace nucleus o
f an embryo with nucleus of another cell
Clone an embryo Trading of embryo
Human cloning in China 人类辅助生殖技术与人类精子库相关技
术规范、基本标准和伦理原则 (Oct. 1, 2003) – by Ministry of Health
Prohibits surrogate mother Prohibits reproductive human cloning Prohibits donation of embryos Prohibits trading of eggs
CLONAID™ was founded in February 1997, by
Raël, the leader of the Raelian MovementRaelian Movement, an international religious
organization, which claims that a human
extraterrestrial race, called the ElohimElohim, used
DNA and genetic engineering, to
scientifically create all life on Earth.
Adapted from Clonaid.com
雷爾教派倡導複製人研究。
Recent Development in Human Cloning
Clonaid claimed to give birth to ‘Eve’ on 26 December 2002
announced a second birth to a Dutch lesbian woman early in January 2003 and a third to a Japanese couple who "cloned their dead son killed in an accident", plus two others in late January
Recent Development in Human Cloning Korean Scientists led by Dr. Woo-suk Hwang
produced cloned human embryos (Science, Feb. 12, 2004) – later found to be fabricated
American scientist Panayiotis Zavos claimed to have cloned 14 human embryos and transferred 11 of them into the wombs of four women (April, 2009)
Recent Development in Human Cloning August 2004 - UK granted the first licence for
work toward therapeutic cloning. Nov. 2004 - Californians passed a $3 billion me
asure to create an Institute for Regenerative Medicine based on embryonic stem cell research.
Please consider ...... Would the views of animal and human
cloning differ among people with different religious believes?
Is embryo a living human? Since the use of stem cells for
therapeutic cloning is still in experimental stage, would the use of cells from embryo be acceptable?
How about using the embryos left over after in vitro fertilization?
Please consider ...... Is reproductive cloning a violation
of natural birth? How about the cloning of a
beloved one who dies accidentally? How about cloning for sterile
couples? Under what circumstances do you
want to make a copy of yourself?
End
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