jayanti tokas, ms, phd 1 ; rubina begum, ms. phd 1 ; shalini jain, ms, phd 2 and hariom yadav, ms,...
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Jayanti Tokas, MS, PhD1; Rubina Begum, MS. PhD1; Shalini Jain, MS, PhD2 and
Hariom Yadav, MS, PhD2
1Department of Biotechnology, JMIT, Radaur2NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
Corresponding: yadavhariom@gmail.com
Cloning means making an organism identical to another
In nature :- Identical Twins
Occurs naturally in single celled organisms
Cloning
Scientific technique to create genetically identical organisms
Production of one or more individual plants or animals(whole/in part) that are genetically identical
Types of Cloning
1.Embryo Cloning
2.Reproductive cloning
3.Therapeutic Cloning
a) Embryo cloning
Produce mono zygotic twins or triplets
Fertilized embryo remove
one/more cells
Encourage to develop into embryo
Twins /triplets have identical DNA
b) Reproductive cloning
Produce a duplicate of existing animal
Used to clone sheep & other mammals
Produce several genetic defects
Medical ethicists- Immoral procedure to be done on humans as it is unsafe & unethical
Newly formed embryo containing DNA from somatic cell
cell division
implant
(Diploid )
(Amy Coxon.,2001)
c) Therapeutic Cloning
Somatic Cell Nuclear Transfer(SCNT)
Biomedical Cloning
Research Cloning
Regenerative Medicine
Nuclear Transplantation Therapy(NTT)
Therapeutic cloning (research cloning) is when stem cells are extracted to grow into a piece of human tissue which is encouraged to grow into a human organ for transplant
Therapeutic Cloning
DNA is extracted from a human’s cell
inserted into a woman’s ovum
develop and produce stem cells.
stem cells are removed from the pre-embryo
grown into specific organ
transplanted into the patient.
Culturing of pluripotent Stem Cell from fertilized embryo
(David Cameron, 2001)
Culturing of pluripotent Stem Cells from cloned embryo
(David Cameron, 2001)
Need for Therapeutic Cloning
o Implantation of human Embryonic stem (ES) cells is not safe unless they
contain patient’s own DNA
o Efforts to repair central nervous system (CNS) disorders
o Strictly Regulated
Technology behind Therapeutic Cloning
• Removing nucleus of egg cell
• Replace with nucleus of a somatic cell
• Stimulate cell division
Removal of nucleus from adult cell
(Irving Weissman,2002)
Transfer of nucleus to enucleated oocyte
(Irving Weissman,2002)
Selection of embryonic stem cells
Cloning Techniques
1. Roslin technique
2. Honolulu technique
Isolation of Donor Cell
(Ian Wilmut,1995)
Fusion of Donor nucleus to enucleated embryo
(Ian Wilmut,1995)
Honolulu technique
• Developed at University of Hawaii, Honolulu
• Does not use electric charge for cell fusion
• Fused cell- given a chemical bath
• Three donor cells- sertoli, neuronal & cumulus cells
Value of Therapeutic Cloning for patients
Potential application in commonly occurring diseases
• Heart disease
• Insulin dependent diabetes
• Parkinson disease
• Burns
Most attractive feature :-
Create perfectly matched transplant material
Mitochondrial Disease
Mitochondria are component of cells inherited from mother’s egg
They carry their own genes & are crucial to fundamental process in all the body cells
Create New ES cells
Cells currently available for research are insufficient because:-
* Not sufficiently racially or ethnically divers
* Scientist need more cell lines to fulfill the promise of stem cell research
Problems associated with Therapeutic Cloning
1. Developing cures
2. Is an embryo a human person ?
3. Stability of stem cells
4. Where would the eggs come from ?
Ethical concern about Therapeutic Cloning
1. Moral status of organisms created by cloning
2. Getting stem cells
3. Getting eggs
Getting Stem Cells
• Adult organs (morally OK ,not technically)
• Fetal tissue
Getting eggs
Health risk concerning the donors
Paying the donors- commercializing the human reproductive material
Ethical issue related to donors
Therapeutic Cloning is governed by-
Human Fertilization and Embryology Authority (1990)
• Authority is administered by- HFEA which can only license research on embryos up to
14 days old for designate purposes
Create cloned Human cells
Use to
* better understand human development
* provide resources for Stem cell research
* develop new treatment for disease
Application in genetic disease,serious injury
Opportunity to obtain perfectly matched transplant tissue for treating presently incurable condition
May lead to development of sophisticated alternatives that do not require eggs, embryonic cells
Practical clinical application not expected for at least 10 year
Public opinion
55% want to ban reproductive cloning but allow TC
30% want to ban both
12% want no ban to both
3% undecided
Hence,TC has come in Law
(CAMR,March2003)
“To allow cloning would be to move towards a society in which human beings are grown for spare body parts & children are engineered to custom specification – that is not acceptable”
I believe all human cloning is wrong …..
any thing other than a total ban on human cloning would be unethical
President Bush says on Stem cell policy
1. Treatment for:-
Diabetes, Heart diseases ,Parkinson's disease, Disease of Bone & cartilage, Immunodeficiency diseases
2. Infertility treatments or to assist couples who know that one parent carries gene for potentially lethal disease
3. Prevent mitochondrial disease
4. Help scientist to understand how stem cell develop
5) Understanding how nuclear reprogramming occurs during CNR would eventually help scientists develop alternative Stem cell therapy techniques that reprogram cells without the need to use eggs, embryos or cloning
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