Transcript Advances in Genetic Traits

See if you can answer this question…
What do you think all of these things
have in common?
 Land mines
 Bacteria on your teeth
 Burping sheep
Advances in Genetics
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What are some advances in genetic
traits due to manmade influences?
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Vocabulary:
selective breeding
clone
genetic engineering
gene therapy
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‘Dolly’
Summer of 1996 in Scotland
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Ordinary lamb
‘except’ produced in
a laboratory by
geneticists using
experimental
techniques
techniques new
trying to get specific
traits is not new
1000 years desirable
traits
Three methods that people have used to
develop organisms with desirable traits:
1- selective breeding
2- cloning
3- genetic engineering
1-Selective Breeding
-process of selecting a few organisms
with desired traits to serve as parents of
the next generation.
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5,000 y.a. Central Mexico
used wild grass as food
saved seeds from plants that produced the most food.
grew new plants
same process over and over
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Today?
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Selective breeding is used on many
different plants and animals to ‘increase
their value’ for people.
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Cows
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Fruits & Veggies
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Milk
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No diseases/pests
Types of Selective Breeding
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A. Inbreeding
- crossing two individuals that have identical or similar
alleles.
-causes offspring to have similar alleles to parents
Horse with speed
X
Horse with speed
= Faaaaast Horse!!!!
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B. Hybridization
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breeders cross two genetically different
individuals
best traits from both parents
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Selective_Breeding.mp4
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ex:
many kernal corn + disease resistant corn
=many kernal, disease resistant corn
hybrid.
2- Cloning
-organism genetically identical to the organism
from which it was produced.
Plants
-’cuttings’ ex. Ivy
 Animals
-more difficult than plants ex. Dolly
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How Dolly was cloned...
Sheep #1
6 yrs. Old
take nucleus out
of an egg cell
‘clone’ (Identical)
to 6 yr. Old sheep
Sheep #2
Take egg cell out
Sheep #3
Put in egg cell
with nucleus
3- Genetic Engineering
-genes from one organism are transferred into
DNA of another organism
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-’gene splicing’
DNA molecule unzipped and new gene put
into it
ex: medicines, improve food crops, cure
human disorders like diabetes.
a. in bacteria
b. other organisms
c. Gene Therapy
- use genetic engineering to correct
genetic disorders.
Some problems biotechnologists are
working on:
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• No more brushing
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• Stopping sheep burping
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• Detecting land mines
No more brushing
Problem:
Problem: Certain bacteria on our teeth produce lactic acid.
The build up of the lactic acid leads to the decaying of our
teeth.
How do we stop this?
Solution: Alter the bacteria so it does not produce lactic
acid.
Of course dentists might say you will still need to
visit them even if you do have genetically modified
bacteria on your teeth…
Stop that burping
Problem: Livestock are responsible for about 90 percent of
Australia's methane emissions in the agriculture sector. Sheep
produce about 25 litres of methane each day.
How do we reduce these methane emissions?
Stop that burping
Solution: Develop vaccines which inhibit the
growth of the bacteria which produce methane.
Plants detecting landmines
Problem: Landmines represent a significant problem in the third
world, where approximately 26,000 people are killed or injured
every year.
Another problem is that large areas of land used for agriculture
(eg Cambodia 40% and Angola 90%) are unused which can lead
to severe consequences for the countries.
Plants detecting landmines
The thale cress turns red when its roots encounter the byproducts of land mines.
(Image: Aresa)
Solution: Genetically modify plants to enable easy
detection of land mines.
There are many other
applications…
Current examples of this
include:
Canola – herbicide resistant
 Cotton – Bt insecticide
 Carnation – blue & long life
 Soybeans – herbicide
 resistant
 Papaya – disease resistant
 Photo courtesy of: CSIRO
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Public concerns
Some people are worried about various applications of
gene technology and raise questions about the safety of
GM foods, the risk of developing herbicide resistant
weeds and other possible environmental
damage.