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BT11.03: Evaluate therapeutic vs. reproductive cloning. Tuesday. What is an example of pharming? A. Using transgenic animals to produce substances used in medicine B. Using viruses to transfer genetic information C. Improving livestock with transgenic research
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Tuesday • What is an example of pharming? • A. Using transgenic animals to produce substances used in medicine • B. Using viruses to transfer genetic information • C. Improving livestock with transgenic research • D. Using transgenic mice to study cancer, MS and muscular dystrophy
History of cloning • Dolly the sheep – first cloned mammal in 1997*** • Very few scientists believe human cloning (reproductive cloning) should be permitted • Most scientists in favor of therapeutic cloning ***– the procedure used to produce embryonic stem cells that theoretically can be used to treat diseases
What is a clone? • Clone = precise genetic copy • Reproductive cloning is really somatic cell nuclear transfer (SCNT) • In therapeutic cloning, the embryo is not placed in a surrogate, but rather, undergoes cell division in the lab until it reaches blastocyst stage • There is currently no evidence of successful human cloning in the world***
Obstacles to reproductive cloning using animals • Success rate very low • Vast majority of problems occur during fetal development • Additional problems show up after birth and years later • “Large offspring syndrome” = cloned newborns 20-30% larger than usual, making it hard to deliver unborn babies
Embryonic and adult stem cells • Adult stem cells • Embryonic stem cells • Stem cells are important to medical researchers because they may be used to create perfectly matched tissue to treat an individual disease or disorder*** • Scientists may create a new human stem cell line if private funding resources are used***
Why would a person need an adult stem cell transfusion? • When a radiation treatment for cancer has destroyed the person’s stem cells***
Differences between reproductive cloning, therapeutic cloning, and stem cell research • Goal of reproductive cloning is to create a new organism, human or animal • Goal of therapeutic cloning is to produce embryonic stem cells • The purpose of performing embryonic stem cell research is to develop new and better ways to treat disease
Human stem cell research • 2001 legislation allowed federal funding of research using 64 existing human embryonic stem cells • Same legislation declared no federal funds for additional research.
Therapeutic potential of stem cells • Researchers must use existing human stem cell lines for research or find private funding sources • Creation of embryonic stem cells does not use fertilized egg • On the other hand, it does have the potential to become a living thing if transplanted into the uterus
Therapeutic potential of stem cells (continued) • Real advantage of stem cells – permits the production of perfect-match tissue • Scientists have found that embryonic stem cells pick up cues from neighboring cells and differentiate into that cell type • Scientists hope stem cells will be used to treat heart disease, Parkinson’s disease, other disorders of the nervous system