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1、Ethical Issues on Animal and Human cloning Prof. P.C. Shaw (邵鵬柱教授) Department of Biochemistry, CUHK Hong Kong Bioethics Association November 2009 複 製 人 ? History of cloning n1952 Northern leopard frogs cloned. n1953 Structure of DNA discovered. History of cloning n1978 Louise, the first child concei
2、ved through in vitro fertilization, was born. n1993 Human embryos were first cloned (artificial embryo twinning) nJuly 5, 1996Dolly was born. Photo from: Dolly the first mammal cloned using mature cell nDolly the Lamb in 1996 nMethod: Nuclear transfer nOrganization: Roslin Institute at UK and PPL T
3、herapeutics Photo from Ming Pao 18th August 2002 Example of cloning nCumulina the Mouse in 1998 nOrganization: University of Hawaii Photo from Ming Pao 28th December 2002 Example of cloning nCattle in 1998 nOrganization: Kinki University at Japan Photo from Ming Pao 28th December 2002 Example of clo
4、ning nMille, Christa, Alexis, Carrel and Dotcom the Pigs in 2000 nOrganization: PPL Therapeutics of UK Photo from Ming Pao 28th December 2002 Example of cloning nCarbon Copy the Cat in 2002 nOrganization: Texas A & M University, USA Photo from Ming Pao 23th January 2003 Example of cloning nGeneratio
5、n of Prometea, 2003 nOrganization: A research laboratory in Italy Photo from Nature No.6949 Examples of cloning nCloning of donkey, 2004, USA nCloning of dog, 2005, Korea nCloning of rhesus monkey, 2007, Oregon, USA http:/jamaica- http:/www.pbs.org/newshour/bb/science/july-dec07/stemcells_11-15.html
6、 Two methods of cloning nEmbryo cloning 胚胎複製 - remove a cell from an embryo for developing into a separate embryo. nAdult cell cloning 成長細胞複製 - replace DNA/nucleus from a cell by another. Two methods of cloning nEmbryo cloning 胚胎複製 do not know the characteristics of the offspring. nAdult cell clonin
7、g 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 , How to generate Dolly? Step 2. Unfertilized egg cell was taken from a
8、nother sheep. The nucleus was removed, leaving an empty egg. Photo from www.pbs.org. , 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 . How to generate Dolly? Step 4. After
9、 6 days, the resulting embryo was implanted into another sheep (surrogate mother 代母). Photo from www.pbs.org, 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 cloni
10、ng nCan produce animal with a desired trait, for nProtein products, organs nProliferate endangered animals Cloning of endangered animal nNoah the Gaur (亞洲野牛, an endangered species) in 2000 nOrganization: Advanced Cell Technology, USA Photo from Advanced Cell Technology () Cloning of endangered anima
11、l nCloning of woolly Mammoth (長毛象) nExtinct 10,000 years ago nIs there any intact cell left? From Mingpao 8/8/2003 Cloning of transgenic animal nCloning of a cow containing mad cow disease resistant gene nIn Shangdong, China From Mingpao 28/4/2006 Concerns in animal cloning nTechnology complicated n
12、Survival rate of cloned embryos low nOverweighing of calves at birth nBreeders may want to keep their animal unique nBreeders may want to create better offspring Health of clones From Ming Pao 27-Mar-2001 Poor development of heart, lung and immune system Might have genetic disorder Photo from Mingpa
13、o Dolly gave birth to a female lamb in 1998, but Dolly later died of premature aging in 2003. Company for cloning pets nGenetic Savings & Clone established in 2000, produced the cloned cat, CC in 2001 nDelivered the first commercially cloned cat, Little Nicky in 2004 for US$50,000 nCompany closed in
14、 2006 nA new company BioArts International was established for cloning dogs Commercial pet cloning may not be a good investment nDemand not high nCompetition from developing countries nDisregard of the IP issues nRelaxed treatment of animals nThe IP holder does not want to defense the IP rights nOut
15、come is unpredicted cloning is not a mature techniques nPressure from the society Cloning Human Cloning two kinds nReproductive cloning an embryo is created and implanted into a womans womb to bring it to term. nTherapeutic cloning an embryo is created in order to obtain cells from it. Why clone hum
16、an? nJust an unconventional means of reproduction nIn vitro fertilization nSurrogate mother nAdoption nStudy human development nProduce spare parts nTest for genetic defect nIncrease chance of pregnancy nProduce two children at the same time Why clone human? nPreserve traits and talents nExtension o
17、f life in unusual circumstances nOne spouse sterile nHomosexual marriage Why clone human? nCloned embryos provide : nBrain cells for disorders like Parkinson (柏金遜) and Alzheimers disease (老年 痴呆症) nPancreatic islet cells for diabetes (糖尿) Positive points of therapeutic cloning nCloned embryos provide
18、 : nNerve cells for spinal cord damage ( 脊椎受損) nBlood 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 cellsAdult stem cells The use of stem cells to generate clones http:/www.genetic
19、sandsociety. 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
20、 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? nEugenic (優生) to maximize certain traits intentionally nReduce genetic diversity nUse as substitute for organ nClone may have re
21、duced life expectancy nClone may be abnormal Why not perform reproductive cloning? nLack of self-identity nReplaceable nDominated by the father or mother Why not perform reproductive cloning? nUpset traditional family relationship nTwin of the cell donor? nRelationship with its brother and sister nR
22、elationship with spouse of the cell donor Human Reproductive Technology Bill 香港人類生殖科技條例 (2000) nNot allow the followings: nReplace nucleus of an embryo with nucleus of another cell nClone an embryo nTrading of embryo Human cloning in China n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
23、of Health nProhibits surrogate mother nProhibits reproductive human cloning nProhibits donation of embryos nProhibits trading of eggs CLONAID was founded in February 1997, by Ral, the leader of the Raelian Raelian MovementMovement, an international religious organization, which claims that a human e
24、xtraterrestrial race, called the ElohimElohim, used DNA and genetic engineering, to scientifically create all life on Earth. Adapted from C 雷爾教派倡導複製人研究。 Recent Development in Human Cloning nClonaid claimed to give birth to Eve on 26 December 2002 nannounced a second birth to a Dutch lesbian woman ea
25、rly 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 nKorean Scientists led by Dr. Woo-suk Hwang produced cloned human embryos (Science, Feb. 12, 2004) later found to be fabricated
26、nAmerican 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 nAugust 2004 - UK granted the first licence for work toward therapeutic cloning. nNov. 2004 - Californians passed a $
27、3 billion measure to create an Institute for Regenerative Medicine based on embryonic stem cell research. Please consider nWould the views of animal and human cloning differ among people with different religious believes? nIs embryo a living human? nSince the use of stem cells for therapeutic clonin
28、g is still in experimental stage, would the use of cells from embryo be acceptable? nHow about using the embryos left over after in vitro fertilization? Please consider nIs reproductive cloning a violation of natural birth? nHow about the cloning of a beloved one who dies accidentally? nHow about cloning for sterile couples? nUnder what circumstances do you want to make a copy of yourself? End