Download Gene Technology

Gene Expression
0 Genome
0 Our complete genetic information
0 Gene expression
0 Turning parts of a chromosome “on” and “off”
Gene Expression
0 Uncoiled chromosomes are
called euchromatin
0 We have two parts to our
genes
0 1. Introns
0 Transcribed but not
translated
0 Cut out of mRNA before
leaving nucleus
0 2. Exons
0 Transcribed and translated
0 Codes for a protein
http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120080/bio31.swf
Transcription
0 DNA  mRNA
0 After mRNA has been made in the nucleus
0 Introns are spliced out of the mRNA
0 Exons bind together
0 Addition of 5’ cap and poly A tail
Gene Regulation
0 Similar to bacteria except out genome is much larger
and more complex
0 98% of our DNA does not code for a protein
0 Each person has a specific number of non-coding
regions between exons
0 Called VNTR (Variable Number Tandem Repeats)
0 Nonsense repeats in tandem
DNA Identification
0 Used to identify criminals
in a crime scene or to see
family relation
0 Four steps to use DNA
identification
0 1. Isolate DNA (make
copies if small sample)
0 2. Cut DNA in fragments
that are known VNTR
areas
0 3. Sort DNA by size (using
technology)
0 4. Compare size fragments
to known samples
http://www.youtube.com/watch?v=ZxWXCT9wVoI
How to Make DNA Copies
0 Process called PCR
0 Technology where a small DNA sample can be amplified
to many copies for analysis
PCR Steps
0 1. Add sample of DNA, DNA polymerase enzyme, free
nucleotides (to make new strands with) and heat
sample
0 The heat will act like helicase and separate the strands
of DNA
PCR Steps
0 2. Cool sample down so primers can be added to DNA
template strands
PCR Steps
0 3. DNA polymerase attaches to primers and adds
nucleotides to rest of DNA template strands
PCR Steps
0 4. Two new strands are made  repeat process until
enough DNA sample
http://www.youtube.com/watch?v=2KoLnIwoZKU
http://www.youtube.com/watch?v=eEcy9k_KsDI
Cutting DNA
0 Technology that cuts long
strands of DNA
0 Biologists use restriction
enzymes in order to cut the
DNA
0 Biological scissors
0 Restriction enzymes can
recognize specific sequences
and only cut in certain areas of
DNA
Cutting DNA
0 Sometimes when restriction enzymes cut DNA they
leave an overhang
0 Creates “sticky” ends where you can then add
recombinant DNA
0 Used to input DNA from other organisms into a genome
http://highered.mcgrawhill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120078/bio37.swf
Gel Electrophoresis
0 Technology that separates DNA fragments by size in a
gel to compare to known samples
Gel Electrophoresis
0 How to run a gel:
0 1. DNA sample goes through restriction enzymes to
break into fragments of known VNTRs
0 2. Each DNA sample (now cut up) gets added into its
own chamber well
Gel Electrophoresis
0 3. Electric current is run through the gel for a specific
amount of time
0 DNA is negatively charged
0 End of gel is positively charged
0 When current runs, the DNA fragments move towards
the end of the gel
Gel Electrophoresis
0 4. DNA is transferred to a nylon membrane where
probes are added
0 Probes bind to complementary DNA
Gel Electrophoresis
0 5. X-ray film exposes membrane
0 This creates a band pattern that is unique to each
individual
0 Called a “bio fingerprint”
0 You can create a permanent copy of results if needed to
file
Gel Electrophoresis
0 How to read results:
http://learn.genetics.utah.edu/content/labs/gel/
Recombinant DNA
0 Genetic engineering:
modifying a genome of
living cell
0 When you combine two
DNA strands from different
organisms it is then called
recombinant DNA
Cloning
0 Clone
0 Exact copy of DNA, a cell or an organism
0 Clones can be created by inserting DNA
into vectors
0 Vectors are organisms that can replicate
itself
0 Ex: bacteria, yeasts
Cloning
0 1. Egg cells are extracted from one organism and the
nucleus is removed
0 Nucleus removed because the DNA of the organism we
want needs to fuse into the egg
0 Cells from organism we wish to clone are removed
Cloning
0 2. Desired organisms cell is placed next to egg cell and
electric shock fuses the two cells into one
0 This triggers the new embryo to begin to divide and
develop
Cloning
0 3. Developing embryo is implanted in a surrogate
mother and after incubation period is over, a new
baby organism is born with the exact same genetic
information as original organism
http://www.youtube.com/watch?v=-Qry1gYYDCA
http://www.youtube.com/watch?v=tELZEPcgKkE
Vaccines
0 Substance containing all or part of a harmless strain
of a pathogen
0 This gets introduced to our body and we build an
immunity for it creating a defense system against the
pathogen called antibodies
0 DNA vaccine: vaccine containing genes from pathogen
but will not cause infection
http://www.youtube.com/watch?v=SduMbjW2V9A
http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120078/bio39.swf
Agricultural Applications
0 Made plants more tolerable to our environment
0 Resistance to weeds
0 Added genes that would be harmful to insects and pests
0 Increase nutritional value to some plants
0 Ex: adding vitamin A to rice in Asia
http://www.youtube.com/watch?v=FTfuAbzAeB8 – food http://www.youtube.com/watch?v=JVIznPgdQSM – animals