DNA Cloning: •DNA segment--> plasmid--> bacteria •plasmid replicates •bacteria replicates •Lots of that DNA!
Why artificial clone? Agriculture (apples) Domestic animals Drug production Organ source Race horses!
Totipotent Stem Cell (Zygote)
Pluripotent Stem Cell
Adult Stem cell
Adult Differentiated Cell
Cell Differentiation:
Dolly the sheep cloned (1997) Somatic-Cell Nuclear Transfer
Adult cell nucleus --> becomes totipotent
1998 Mice cloned1998 Cows cloned1998 Last Enderby Cow cloned2000 Pigs cloned2002 CC the cat cloned2003 Horses cloned2003 Rat cloned2005 Dog cloned
Zygote -- Totipotent Cell
Early embryo -- Pluripotent
Cells become specialized Multipotent Oligopotent Unipotent
Stem Cell Types
How to obtain STEM CELLS?
Early embryos (totipotent) ESCLater embryos (Pluripotent) ESCCloning
Adult Stem Cells = ASC
Use Zygote Totipotent
Scientific: Best source of SCMedical: Nonself!Ethical: Taking a human life Origin of the zygotes
Harvest Embryonic Stem Cells
Pluripotent
Scientific: Best source of SCMedical: Nonself!Ethical: Taking a human life Origin of embryos
Sometimes Totipotent (2-5%)Cloning via Somatic-Cell Nuclear Transfer
Scientific: Programming?Medical: Nonself! Or self! ProgrammingEthical: Taking a human life Need eggs - whose?
Adult Stem Cells: DO THEY EXIST?
Neural stem cells: neurons + glial 1:300 in brain Can get 80% pure SC Works in mice Origin for human use?? Non-self!
Induced Pluripotent Stem Cells iPSC
Shinya Yamanaka
Only 4 (later 3) factors neededPut into cell with virusLater use other methods
Induced Pluripotent Stem Cells iPSC
Scientific: Wonderful (are they?)Medical: Self!! Yippie! (or????)Ethical: Are they totipotent??
Induced Pluripotent Stem Cells iPSC
Scientific: Programming!Medical: Programming!Ethical: Are they totipotent??
Induced Pluripotent Stem Cells iPSC
The Benjamin Button Cell
“There were no troublesome memories in his childish sleep.”
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