Transcript What is Cloning?

What is Cloning?
An exact genetic copy of an
organism
(identical twins are natural clones)
Two Ways to Do It
Artificial embryo twinning
Somatic cell nuclear transfer
What????????
Artificial Embryo Twinning
Separate an early embryo into two cells
Allow each to divide and develop on its
own
Place in a surrogate mother
Allow to grow and develop
Somatic Cell Nuclear Transfer
Somatic cells are cells in the body except
the sperm and egg. Every somatic cell
has two sets of chromosomes in a
mammal.
Isolate a somatic cell
Transfer the nucleus to an egg cell that has had
its original nucleus removed
The egg cell will develop like a fertilized zygote
(method used to create Dolly the sheep)
Dolly
 Dolly, the first mammal to be cloned
from adult DNA, was put down by
lethal injection Feb. 14, 2003.
 Prior to her death, Dolly had been
suffering from lung cancer and
crippling arthritis.
 Although most Finn Dorset sheep
live to be 11 to 12 years of age,
postmortem examination of Dolly
seemed to indicate that, other than
her cancer and arthritis, she
appeared to be quite normal.
 The unnamed sheep from which
Dolly was cloned had died several
years prior to her creation.
 Dolly was a mother to six lambs,
bred the old-fashioned way.
Cloned Foods
Currently there are only a small number of
cloned farm animals in the United States.
According to a recent Washington Post, there
are 150 cloned cows out of 9 million dairy cows
in the United States, which each clone costing
about $20,000 to produce.
The expense alone should keep the
number down.
Draft Risk Assessment
 Something we could do
 Copies of the Draft Risk Assessment may be requested from the
Communications Staff (HFV-12), Center for Veterinary Medicine, Food and
Drug Administration, 7519 Standish Place, Rockville, MD 20855, and may
be viewed on the Internet at http://www.fda.gov/cvm/cloning.htm

 FDA is seeking comments from the public on the three documents for the
next 90 days. To submit electronic comments on the three documents, visit
http://www.accessdata.fda.gov/scripts/oc/dockets/comments/commentdocke
t.cfm?AGENCY=FDA. Written comments may be sent to: Division of
Dockets Management (HFA-305), Food and Drug Administration, 5630
Fishers Lane, Rm. 1061, Rockville, MD, 20852. Comments must be
received by Apr. 2, 2007 and should include the docket number 2003N0573.
Genetically Modified Foods and
Organisms
Genes from different organisms that
improve taste and nutritional value or
provide resistance to particular types of
disease can be used to genetically
engineer food crops.
Uses recombinant DNA technology
What????
1996 1st
biotech crops
on 7 million
acres
2006 = 252
million acres
This is 13%
more than in
2005
http://www.bio.org/ataglance/acreage.asp
GM Foods
 In 2003, about 167 million acres (67.7 million hectares)
grown by 7 million farmers in 18 countries were planted
with transgenic crops, the principal ones being herbicideand insecticide-resistant
soybeans, corn, cotton, and canola.
 Other crops grown commercially or field-tested are
 a sweet potato resistant to a virus that could decimate
most of the African harvest,
rice with increased iron and vitamins that may alleviate
chronic malnutrition in Asian countries, and
a variety of plants able to survive weather extremes.
US Department of Energy
U.S. Department of Energy Human Genome Program, http://www.ornl.gov/hgmis.
Cloning DNA in Plasmids
 By fragmenting DNA of any origin (human,
animal, or plant) and inserting it in the DNA of
rapidly reproducing foreign cells, billions of
copies of a single gene or DNA segment can be
produced in a very short time.
DNA to be cloned is inserted into a plasmid (a small,
self-replicating circular molecule of DNA) that is
separate from chromosomal DNA.
When the recombinant plasmid is introduced into
bacteria, the newly inserted segment will be replicated
along with the rest of the plasmid.
http://www.biology.arizona.edu/
Cut DNA with
restriction enzyme
Join vector and DNA
fragment using DNA
ligase
Recombinant
molecule
Introduce recombinant
into bacterium
image credit: U.S. Department of Energy Human Genome Program, http://www.ornl.gov/h
Inserting Bt toxin gene
into corn
 Isolate the genetic
material in Bt
 Insert gene into DNA
carrier
 Vector carrier into the
plasmid
 Plasmid inserts DNA into
the corn cell genome
 Grow your corn!
Art by Jiang Long and Jen Philpot
Bt Corn
A bacterium, Bacillus thuringiensis, and
the gene of interest produces a protein
that kills Lepidoptera larvae (European
corn borer).
This protein is called the Bt delta
endotoxin.
Growers use Bt corn as an alternative to
spraying insecticides for control of
European and southwestern corn borer.
 The Bt gene, from Bacillus thuringiensis, produces a toxin that protects
against caterpillars, reducing applications of insecticides and increasing
yields.
 The glyphosate resistance gene protects food plants against the broadspectrum herbicide Roundup, which efficiently kills invasive weeds in the
field.
 The major advantages of the "Roundup Ready®" system include better weed
control, reduction of crop injury, higher yield, and lower environmental impact
than traditional herbicide systems.
 In 2004, approximately 85% of soy and 45% of corn grown in the U.S. were
grown from Roundup Ready® seed.
 Most Americans would probably be surprised to learn that more than 60% of
fresh vegetables and processed foods sold in supermarkets today are
genetically modified by gene transfer.
http://www.dnalc.org/home.html
Taste Testing Soon
Wednesday Sam Ball (Guest Speaker)
about what we are doing on campus for
sustainability
Next exam questions soon too
http://vm.cfsan.fda.gov/~lrd/biotechm.html