Download Manipulating DNA

Manipulating DNA
Selective Breeding
• Man has selectively
bred plants and
animals for desired
traits
Mutations of Pointsettias induced
by radiation
New DNA Technology
• Now DNA can be
manipulated to
produce new
combinations not
found in nature
• How far should we
go?
– We need to set
bioethical limits
Restriction Fragment Length Polymorphism
(RFLP) Analysis
• DNA is cut into small
pieces using restriction
enzymes
• Many copies are made
using PCR
• Radioactive probes
attached to mark ends
• An electric current is used
to separate pieces by
size in a gel
– Larger pieces are slower
and don’t move as far
down the gel
http://www.sumanasinc.com/webcontent/anima
tions/content/gelelectrophoresis.html
DNA Fingerprinting
• DNA is unique for every
individual
• Comparing the
sequences of small
pieces of DNA can be
used:
– Find relationships
– Narrow crime suspects
– Identify organisms
Tools needed in Gene Cloning
• Restriction enzymes
– Cuts the desired DNA strands
• Bacterial plasmid
– cloning vector used to move
DNA to another organism
• Host DNA
– Donor gene(s)
Produces a transgenic
organism with recombinant
DNA
Clones
• Copies of one organism
Clones
• Produced by taking cuttings from one plant
– Grafting
– Budding
– Rooted cuttings
Clones
• Produced for many years by dividing an embryo
to form identical quadruplets
– Cows
– Pigs
A New Type of Clone
• The nucleus of a donor cell
• The ova (egg) of another organism
• A surrogate mother
How it’s done…
FDA says cloned animals safe to eat
• Food producers, including
Tyson Foods Inc. and Dean
Foods Co., said they won't
use cloned foods anytime
soon.
• Bloomberg News / January
16, 2008
• WASHINGTON - Cloned
cows, pigs, goats, and their
offspring are safe to enter
the US food supply,
regulators said over protests
from lawmakers, consumer
groups, and worried eaters.
Maryann Mott
for National Geographic News
Champion Horse Cloned by Texas Breeder
April 4, 2006
Meet Royal Blue Boon Too, the first commercially cloned horse in
the United States.
The cost of the frisky foal: U.S. $150,000.
That may be a bargain, considering that the original Royal Blue
Boon, a 26-year-old American Quarter Horse now past
breeding age, has earned more than $380,000 as a competition
and show horse.
.
Controversial topics…
• Scientists hope to use cloned embryos to harvest precious "stem
cells" — cells that, in theory, can ultimately grow into any kind of cell
in the body.
• These cells could be used to generate new organs or cell clusters to
treat patients with failing organs or degenerative diseases
•
In the case of transplant patients, organs made from exact copies of
an individual's own cells and would not be rejected.
• This research is still in its earliest phase of development. All of the
embryos generated actually died — none grew beyond the six-cell
stage
• Controversial: The thinking is that by allowing any kind of cloning of
human embryos, it is then not such an enormous leap to apply the
same techniques to making copies of people.
Some problems to Overcome:
• Many casualties
– Birth defects
– Failures
– Premature aging
• Improve technique