BT 11 03 Evaluate therapeutic vs reproductive cloning

BT 11. 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 – D. Using transgenic mice to study cancer, MS and muscular dystrophy

History of cloning Ø Dolly the sheep – first cloned mammal in 1997*** Ø Very few scientists believe human cloning (reproductive cloning) should be permitted Ø 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? Ø Clone = precise genetic copy Ø Reproductive cloning is really somatic cell nuclear transfer (SCNT) Ø In therapeutic cloning, the embryo is not placed in a surrogate, but rather, undergoes cell division in the lab until it reaches blastocyst stage Ø There is currently no evidence of successful human cloning in the world***

Obstacles to reproductive cloning using animals Ø Success rate very low Ø Vast majority of problems occur during fetal development Ø Additional problems show up after birth and years later Ø “Large offspring syndrome” = cloned newborns 20 -30% larger than usual, making it hard to deliver unborn babies

Embryonic and adult stem cells Ø Ø Ø 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*** Ø 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? Ø When a radiation treatment for cancer has destroyed the person’s stem cells***

Differences between reproductive cloning, therapeutic cloning, and stem cell research Ø Goal of reproductive cloning is to create a new organism, human or animal Ø Goal of therapeutic cloning is to produce embryonic stem cells Ø The purpose of performing embryonic stem cell research is to develop new and better ways to treat disease

Human stem cell research Ø 2001 legislation allowed federal funding of research using 64 existing human embryonic stem cells Ø Same legislation declared no federal funds for additional research.

Therapeutic potential of stem cells Ø Researchers must use existing human stem cell lines for research or find private funding sources Ø Creation of embryonic stem cells does not use fertilized egg Ø 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) Ø Real advantage of stem cells – permits the production of perfect-match tissue Ø Scientists have found that embryonic stem cells pick up cues from neighboring cells and differentiate into that cell type Ø Scientists hope stem cells will be used to treat heart disease, Parkinson’s disease, other disorders of the nervous system