REPRODUCTIVE CLONING Definition = making an exact genetic copy of an organism. Occurs naturally with identical twins Lab methods artificial twinning Somatic Cell Nuclear Transfer
Artificial Twinning Similar to how identical twins form Early stage embryo (blastocyst) is pulled apart artificial twinning process
Somatic Cell Nuclear Transfer Somatic cell = any body cell (not sex cells) Oocyte = egg Enucleated = nucleus is removed; click link and select “Enucleation Video” on right-hand side
Somatic Cell Nuclear Transfer cont. In SCNT, any somatic cell is fused with an enucleated donor oocyte. “Fertilized egg” is given a shock and transferred into a surrogate female. Result is genetically identical to the somatic cell donor. (Animation)
Why Clone? Preserving endangered or recreating extinct animals. Restoring the life of a lost pet.
Why Clone? Making exact copies of livestock or crops that have prized traits.
What animals have been cloned? ANIMALS THAT HAVE CLONED BY SCNT Tadpole Carp Sheep Pig (xenotransplantation = using animal organs in humans) Gaur Cattle Cat Mule Deer Horse (Champion the Wonder Clone) Rat Fruit Flies Dog ANIMALS THAT HAVE BEEN CLONED BY ARTIFICIAL TWINNING Rhesus Monkey
What animals have been cloned? ANIMALS THAT HAVE BEEN CLONED BY ARTIFICIAL TWINNING Rhesus Monkey
Any Problems With Cloning? Video 1. High Failure Rate - Success rate ranges from 0.1 – 3% - Dolly was result of 277 attempts!
Any Problems With Cloning? 2. Large Organ Syndrome Kidney, brain, immune system malformation
Any Problems With Cloning? 3. Abnormal gene expression Same genes, but body isn’t using them the same as the original.
Any Problems With Cloning? 4. Telomere is too short Shorten as we age Dolly started with shorter than normal telomeres Developed arthritis at an early age
Cloning Misconceptions Myth #1 – Instant Clone
Cloning Misconceptions Myth #2 – Carbon Copies Nature vs Nurture In females, X-inactivation - each cell can’t have multiple copies of the X chromosome - each cell randomly chooses which X chromosome to inactivate - female clones are not phenotypic clones
Should we clone humans?