Download Reproductive Cloning Presentation

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?