Transcript Cloning - Somers Public Schools

Cloning
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Growing a population of genetically identical
cells from a single cell.
1997 - Ian Wilmut with Dolly, the cloned sheep
1. Remove nucleus from egg cell
2. Fuse de-nucleated cell with a body cell from
another adult
3. Cells fuse to become 2N and then divides
4. Implant embryo in reproductive system of foster
mother
DNA Fingerprinting
• Using cut DNA at specific sites to determine
the source of the DNA.
• Analyzes sections of DNA that have little to
no function but vary greatly from one person
to the next (called repeats)
• RFLP analysis –
Hello Dolly!
How is it done?
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RFLP analysis – Restriction fragment length polymorphism. We
each have non-coding segments on our DNA. (Junk???)
Extract DNA sample from blood or tissues
Cut DNA using restriction enzymes. Fragment lengths varies with
each person
Separate fragments by gel electrophoresis – separates DNA
fragments by the # of base pairs (length of the fragment)
Place DNA sample into wells in the agarose gel – molecular sieve
Run a current through the gel. The DNA (negatively charged) will
migrate from (-) to (+)
The larger fragments will not migrate that far. The small
fragments will go the furthest.
Stain gel and bands in a dye or use a radioactive probe to analyze
the banding
• Electrophoresis “electro” = electricity “phoros” = to
carry across
• (Nucleic acids or proteins) on the basis of size, electric
charge and other physical properties
Who did it? Suspect #1 or #2
• #1’s fingerprint matches the
evidence left.
• Neither Suspect #2 nor the Victim
matches #1.
• Therefore, #1 did it!!
• Your VNTRs (variable # tandem repeats) are inherited from your
parents
Shown below are the VNTR patterns for Mrs. Nguyen [blue], &
Mr. Nguyen [yellow]
• Their four children:
– D1 (the Nguyens' biological daughter)
– D2 (Mr. Nguyen's step-daughter, child of Mrs. Nguyen and her
former husband [red])
– S1 (the Nguyens' biological son)
– S2 (the Nguyens' adopted son, not biologically related [his
parents are light and dark green]).
Gene Therapy
• Treatment of a genetic disorder by correcting
a defective gene that causes the production
of a defective protein.
• Researchers tried to engineer a virus that
carries a copy of the normal gene to infect
the affected cells
• Has not been proven to be successful yet
How gene therapy works:
Stem Cell Research
• Stem cells are unspecialized cells that
can be induced to specialize into
different tissues
• Embryonic stem cells
–Come from discared embryos no
longer needed for in vitro fertilization
–Can give rise to any other tissue
Stem cell research
• Adult stem cells
– Give rise to only a few types of tissues
– Do not divide long out of the body
• Induced pluripotent stem cells (2007)
– Change adult somatic cells into stem cells
by forced expression of embryonic genes
Legislation on stem cell research lifted
by Obama
• Prior to Obama, the government would not
support stem cell research on embryonic stem
cells, only on adult stem cell and established
embryonic stem cell lines
• 2009 Obama lifted ban and made money
available to scientists for embryonic stem cell
research
Goals of stem cell research
• What are the intended uses of stem cells?
1. Repair damaged tissues in the body
Spinal cord injury, stroke, burns, heart
disease, dabetes, osteoarthritis,
rheumatiod arthritis
2. Possible organ/tissue transplants
3. Treat certain diseases
4. Test new medicaitons