2.11 and 2.112 biotech.ppt

1. If a gray cat is crossed with a black cat, what

is the chance of having a gray cat?

2. Explain how, looking at a pedigree, you can

determine whether a trait is dominant or

recessive?

3. Compare and contrast prokaryotes and

eukaryotes

TOPIC 27

reminder

⚫

Genes are pieces of our DNA

⚫

Transcription converts the information

in genes to mRNA

Biotechnology

Biotechnology is any

Biotechnology

A karyotype is an image of an

individuals chromosomes.

The Human Genome Project

The Human Genome Project was the international project to determine the exact sequence of nucleotides and genes of a person

In 1990, scientists decided it would be good to figure out all of DNA and

therefore, all of our genes

This was a huge, unprecedented effort

Your DNA is about 2 meters long….think of how hard that would be

Importance and Application

So what could we do if we knew our DNA?

◦ See what we are made of – what makes us

◦ Detect Diseases

◦ Ways to treat diseases

● Drugs

● Fix genetic problems ◦ Discover Predisposition

◦ Learn more about Evolution

Importance and Application

The ability to TRANSFORM science and medicine

Scientists are still analyzing the genome

HGP

When they first sequenced all of our DNA, it took 13 years and billions of dollars

The process spurred technological advances

Now, we can sequence your DNA for about $10,000

There have been MANY technological

advances as a result of the HGP

We now the genomes of several other

organisms…and the list is growing!

Genetic Engineering is the transfer of genes from one organism to

another. This new DNA is referred to as recombinant DNA

Stanley Cohen and Herbert Boyer in 1973 were the first scientists to

successfully do genetic engineering.

Only possible because all living organisms use the same genetic cods – universal code!

What is genetic engineering?

Genetic engineering involves building recombinant DNA.

Recombinant DNA is DNA that is made from two different species. Recombinant DNA is formed

when fragments of DNA from two or more different organisms are spliced (joined) together in the

laboratory.

Genetically Modified Organisms or

GMOs

Genetically modified organisms

refer to organisms that have been

modified via genetic engineering.

Engineers isolate a specific gene

from one organism and insert it into

another organism.

Benefits

Genetically modified plants can be

created that are salt tolerant, herbicide

and pest resistant.

Sheep can be genetically modified to

produce Factor IX in sheep milk.

GMOs can help reduce starvation and

Liabilities

There is no way to predict with complete

certainty what effects these genetically

engineered plants may have on the

environment.

Other genetic engineering projects include helping plants become

resistant to weather, fungus, and insects.

Genetic engineering techniques can also be used to produce

bigger, more productive

livestock. Injecting growth hormone into dairy cows will increase milk production.

The addition of growth

hormone potentially will also create new, leaner, faster

growing cattle.

Both fish are the same age, the bigger one has been genetically

engineered.

Human growth hormone is now being tested for dwarfism, a

disorder in which the pituitary gland fails to make enough

growth hormone.

A harmless version of a is

called a vaccine. A vaccine is injected into people so that

their immune systems will develop defenses against the disease.

The body will make defensive proteins called antibodies. If a vaccinated person is exposed to the same

disease-causing microbe, it will immediately begin

large-scale production of the antibodies, which will stop the growth of the microbe before the disease can develop.

Recombinant DNA Technology

How do we “do” genetic

Restriction enzymes

A restriction enzyme

cuts DNA at a specific

nucleotide sequence

Examples

EcoR1

(

E. coli,

1

strain to be discovered)

G * A A T T C

C T T A A * G

HinDII

(Haemophilis influenza, 2

strain)

Steps in Recombinant DNA

Technology

1. Identify the gene to be cloned.

(Most difficult stage)

2. Cleave gene with a restriction

enzyme.

Steps continued

4. Cleave plasmid with same

restriction enzyme (so that the sticky

ends match).

5. Anneal DNA fragments with

plasmid using DNA ligase.

Polymerase Chain Reations are used to create copies of specific segments of DNA

Small samples of blood, semen or hair found at crime scenes often provides an insufficient

amount of DNA to carry out forensic tests without PCR amplification.

Polymerase Chain Reaction

DNA is denatured (destroyed) by high

temperature.

Primers for desired DNA fragment are

attached to each strand.

A new DNA strand is synthesized behind

primers on each template strand.

Continued rounds of amplification swiftly

produce large numbers of identical

Gel electrophoresis

Gel Electrophoresis

separates DNA

fragments created by

restriction enzymes

based on size

The smaller the

fragment, the farther it

travels

Gene Therapy

Gene therapy: A defective

gene is replaced by a

functional gene

the body can make the

correct enzyme or protein

and cure the disease.

First Gene Therapy

1990 at the NIH a 4 year old girl was the

first to undergo gene therapy.

She was born with Severe Combined

Immune Deficiency (SCIDs) and had no

effective immune system.

White blood cells were removed and normal

copies of the defective gene were inserted

Cloning: creating and

identical organism

using the DNA of

another organism

Cloning

Twins are naturally occurring clones.

Cloning to replicate human beings is

considered unethical by the majority of

the scientific community and President

Bush called for a ban on this form of

research.

Stem cells are cells that can

differentiate to a variety of types

of cells.

There are 2 types of stem cells:

Adult stem cells: come from

adults and can produce many

types of cells

Embryonic: come from an

embryo and can produce all

types of cells.

Stem Cells

Stem cells can, theoretically, be

stimulated to grow into any type of

cell.

Stem cells could eventually be used as

treatments or cures for Alzheimer’s,

Parkinson’s disease, MS, rheumatoid

arthritis, or to “grow” new organs

Stem cells used to be harvested from

frozen embryos that were left over from

IVF – currently banned.

Advantage to using own cells is that the

recipient would not have to take

immune-suppressant drugs.

Most controversial of cloning

technologies.

Most arguments related to stem cell research come