2. Mutations
• Types of mutations
– Point Mutations or Substitutions: causes
the replacement of a single base nucleotide
with another nucleotide
• Missense- code for a different amino
acid
• Nonsense- code for a stop, which can
shorten the protein
• Silent- code for the same amino acid
(AA)
5. Mutations
• Types of mutations
– Frame Shift Mutations:
the number of nucleotides
inserted or deleted is not
a multiple of three, so
that every codon beyond
the point of insertion or
deletion is read
incorrectly during
translation.
• Ex.: Crohn’s disease
7. Mutations
• Types of mutations
– Chromosomal Inversions: an entire section of
DNA is reversed.
– Ex.: hemophilia,
a bleeding disorder
8.
9. Human Genome Project
• The Human Genome Project is a
collaborative effort of scientists around
the world to map the entire gene sequence
of organisms.
• This information will be useful in
detection, prevention, and treatment of
many genetic diseases.
11. DNA Technologies
• DNA technologies allow
scientists to identify,
study, and modify
genes.
• Forensic identification
is an example of the
application of DNA
technology.
12. Gene Therapy
• Gene therapy is a technique for
correcting defective genes responsible
for disease development.
• Possible cures for:
– diabetes
– cardiovascular disease
– cystic fibrosis
– Alzheimer's
– Parkinson’s
– and many other diseases is possible.
13. Genetic Engineering
• The human manipulation of the genetic
material of a cell.
• Recombinant DNA- Genetically
engineered DNA prepared by splicing
genes from one species into the cells
of a different species. Such DNA
becomes part of the host's genetic
makeup and is replicated.
14. A Brief History of Genetic
Engineering
• The name is new, the practice is not.
• Plants and animals have been bred for
thousands of years.
• Human breeding has also been done now and
then.
• All of this has worked by trying to enhance
desired characteristics, without knowing how
they are transmitted.
15. Prospects for
Genetic Engineering
• Designing plants & animals “from scratch”
– This is not going to happen anytime soon
• Transgenic Engineering
– Putting genetic information from one type of plant or
animal into another
• Cloning
– Making genetic copies of an existing plant or animal
• Let’s look at the latter two of these.
16. Transgenic Organisms
• An organism is called “transgenic” if it has
genetic information added to it from a
different type of organism.
• Viruses do something of this sort when
they infect plants, animals or humans.
• Humans have begun to do this with plants
and animals.
• We are not yet making flying pigs!
17. Advantages of Transgenic
Engineering
• Plants:
– More disease-resistant
– Larger yields
– More transportable
– More nutritious
• Animals:
– Make proteins for medicinal purposes
– Make organs for transplant to humans
18. Concerns about
Transgenic Engineering
• Plants:
– Are they safe to eat?
– Will they harm wildlife?
– Will some become super-pest weeds?
– Replace or contaminate natural plants?
• Animals:
– Will they be harmful?
– Replace or contaminate natural animals?
19. Cloning
• A “clone” is a copy of something.
• Computers that mimic IBMs are called “clones.”
• In genetics, a clone is a genetic copy of another
organism.
• Clones occur naturally:
– Asexual breeding in plants & lower animals
– Identical twins (triplets) in higher animals
20. A Brief History
of Cloning
• For centuries it has been known that simple
animals – worms & starfish – can be cloned by
cutting them in half.
• This doesn’t work for higher animals!
• Part of the problem is cell specialization:
– Nerve
– Bone
– Muscle, etc.
– We now realize that each specialized cell has all the
genetic information, but much of it is turned off.
21. Cloning in the
20th Century
• We now realize that each specialized cell
has all the genetic information, but much
of it is turned off.
22. Dolly - 1996
• Clone from an adult
sheep cell by Scots
researchers under Ian
Wilmut
• Had only one success in
300 tries.
• Dolly grew to maturity,
and successfully had a
lamb by natural means in
1998.
• But Dolly seems to be
prematurely old.
23. Genetic Engineering
• Genetic engineering techniques are used in
a variety of industries, in agriculture, in
basic research, and in medicine.
This genetically
engineered cow
resists infections of
the udders and can
help to increase
dairy production.
24. Genetic Engineering
• There is great potential for the
development of useful products through
genetic engineering
• EX., human growth hormone, insulin, and pest-
and disease-resistant fruits and vegetables
Seedless
watermelons
are genetically
engineered
25. Genetic Engineering
• We can now grow new body parts and soon
donating blood will be a thing of the past,
but will we go too far?
Photo of a mouse
growing a "human ear"
