英語文檔：(邵鵬柱教授

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,1952 Northern leopard frogs cloned. 1953 Structure of DNA discovered.,History of cloning,1978 Louise, the first child conceived

2、 through in vitro fertilization, was born. 1993 Human embryos were first cloned (artificial embryo twinning) July 5, 1996Dolly was born.,Photo from: ,Dolly the first mammal cloned using mature cell,Dolly the Lamb in 1996 Method: Nuclear transfer Organization: Roslin Institute at UK and PPL Therapeut

3、ics,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,

4、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, 20

5、03 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- /newshour/bb/science/july-dec07/stemcells_11-15.html,Two methods of cloni

6、ng,Embryo cloning 胚胎複製 - remove a cell from an embryo for developing into a separate embryo. Adult cell cloning 成長細(xì)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(xì)胞複製 characteristics

7、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 another sheep. The nucleus

8、 was removed, leaving an empty egg.,Photo from . , ,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 6 days, the resulting em

9、bryo was implanted into another sheep (surrogate mother 代母).,Photo from , ,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 ,Advantages of animal cloning,Can produce animal with

10、 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 (),Cloning of endangered animal,Cloning of woolly Mammoth (長毛

11、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 Ov

12、erweighing of calves at birth Breeders may want to keep their animal unique Breeders 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 Mingpao,Dolly gave birth to a female lamb in 19

13、98, 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 wa

14、s 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 techniq

15、ues Pressure from the society,Cloning Human,Cloning two kinds,Reproductive cloning an embryo is created and implanted into a womans 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 vi

16、tro 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 mar

17、riage,Why clone human?,Cloned embryos provide : Brain cells for disorders like Parkinson (柏金遜) and Alzheimers disease (老年癡呆癥) Pancreatic islet cells for diabetes (糖尿),Positive points of therapeutic cloning,Cloned embryos provide : Nerve cells for spinal cord damage (脊椎受損) Blood and bone marrow cells

18、 for blood cell disorder (血液疾病),Positive points of therapeutic cloning,/bls/stemcells/types-of-stem-cells.shtml,Embryonic stem cells,Adult stem cells,The use of stem cells to generate clones,/article.php?id=257,Creating an embryo through in vitro fer

19、tilization, culturing ES cells derived from it to provide a sufficient population for the tricky task of inserting genes extracting the nucleus of a successfully altered cell to construct a cloned embryo The resulting offspring would have developed from a cell derived from an embryo created with an

20、egg and a sperm, and improved in the laboratory.,Why not perform reproductive cloning?,Eugenic (優(yōu)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

21、 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

22、 allow the followings: Replace nucleus of an embryo with nucleus of another cell Clone an embryo Trading of embryo,Human cloning in China,人類輔助生殖技術(shù)與人類精子庫相關(guān)技術(shù)規(guī)范、基本標(biāo)準(zhǔn)和倫理原則 (Oct. 1, 2003) by Ministry of Health Prohibits surrogate mother Prohibits reproductive human cloning Prohibits donation of embryos

23、Prohibits trading of eggs,CLONAID was founded in February 1997, by Ral, the leader of the Raelian Movement, an international religious organization, which claims that a human extraterrestrial race, called the Elohim, used DNA and genetic engineering, to scientifically create all life on Earth.,Adapt

24、ed from C,雷爾教派倡導(dǎo)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 Januar

25、y,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 De