Gene Technology

1
Gene Technology

• Chapters 11 13

2
Gene Expression

• Genome
• Our complete genetic information
• Gene expression
• Turning parts of a chromosome on and off

3
Gene Expression

• Uncoiled chromosomes are called euchromatin
• We have two parts to our genes
• 1. Introns
• Transcribed but not translated
• Cut out of mRNA before leaving nucleus
• 2. Exons
• Transcribed and translated
• Codes for a protein

http//highered.mcgraw-hill.com/olcweb/cgi/pluginp
op.cgi?itswf535535/sites/dl/free/0072437316
/120080/bio31.swf
4
Transcription

• DNA ? mRNA
• After mRNA has been made in the nucleus
• Introns are spliced out of the mRNA
• Exons bind together
• Addition of 5 cap and poly A tail

5
Gene Regulation

• Similar to bacteria except out genome is much
  larger and more complex
• 98 of our DNA does not code for a protein
• Each person has a specific number of non-coding
  regions between exons
• Called VNTR (Variable Number Tandem Repeats)
• Nonsense repeats in tandem

6
DNA Identification

• Used to identify criminals in a crime scene or to
  see family relation
• Four steps to use DNA identification
• 1. Isolate DNA (make copies if small sample)
• 2. Cut DNA in fragments that are known VNTR areas
• 3. Sort DNA by size (using technology)
• 4. Compare size fragments to known samples

http//www.youtube.com/watch?vZxWXCT9wVoI
7
How to Make DNA Copies

• Process called PCR
• Technology where a small DNA sample can be
  amplified to many copies for analysis

8
PCR Steps

• 1. Add sample of DNA, DNA polymerase enzyme, free
  nucleotides (to make new strands with) and heat
  sample
• The heat will act like helicase and separate the
  strands of DNA

9
PCR Steps

• 2. Cool sample down so primers can be added to
  DNA template strands

10
PCR Steps

• 3. DNA polymerase attaches to primers and adds
  nucleotides to rest of DNA template strands

11
PCR Steps

• 4. Two new strands are made ? repeat process
  until enough DNA sample

http//www.youtube.com/watch?v2KoLnIwoZKU
http//www.youtube.com/watch?veEcy9k_KsDI
12
Cutting DNA

• Technology that cuts long strands of DNA
• Biologists use restriction enzymes in order to
  cut the DNA
• Biological scissors
• Restriction enzymes can recognize specific
  sequences and only cut in certain areas of DNA

13
Cutting DNA

• Sometimes when restriction enzymes cut DNA they
  leave an overhang
• Creates sticky ends where you can then add
  recombinant DNA
• Used to input DNA from other organisms into a
  genome

http//highered.mcgraw-hill.com/olcweb/cgi/pluginp
op.cgi?itswf535535/sites/dl/free/0072437316
/120078/bio37.swf
14
Gel Electrophoresis

• Technology that separates DNA fragments by size
  in a gel to compare to known samples

15
Gel Electrophoresis

• How to run a gel
• 1. DNA sample goes through restriction enzymes to
  break into fragments of known VNTRs
• 2. Each DNA sample (now cut up) gets added into
  its own chamber well

16
Gel Electrophoresis

• 3. Electric current is run through the gel for a
  specific amount of time
• DNA is negatively charged
• End of gel is positively charged
• When current runs, the DNA fragments move towards
  the end of the gel

17
Gel Electrophoresis

• 4. DNA is transferred to a nylon membrane where
  probes are added
• Probes bind to complementary DNA

18
Gel Electrophoresis

• 5. X-ray film exposes membrane
• This creates a band pattern that is unique to
  each individual
• Called a bio fingerprint
• You can create a permanent copy of results if
  needed to file

19
Gel Electrophoresis

• How to read results

http//learn.genetics.utah.edu/content/labs/gel/
20
Recombinant DNA

• Genetic engineering modifying a genome of living
  cell
• When you combine two DNA strands from different
  organisms it is then called recombinant DNA

21
Cloning

• Clone
• Exact copy of DNA, a cell or an organism
• Clones can be created by inserting DNA into
  vectors
• Vectors are organisms that can replicate itself
• Ex bacteria, yeasts

22
Cloning

• 1. Egg cells are extracted from one organism and
  the nucleus is removed
• Nucleus removed because the DNA of the organism
  we want needs to fuse into the egg
• Cells from organism we wish to clone are removed

23
Cloning

• 2. Desired organisms cell is placed next to egg
  cell and electric shock fuses the two cells into
  one
• This triggers the new embryo to begin to divide
  and develop

24
Cloning

• 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?vtELZEPcgKkE
25
Vaccines

• Substance containing all or part of a harmless
  strain of a pathogen
• This gets introduced to our body and we build an
  immunity for it creating a defense system against
  the pathogen called antibodies
• DNA vaccine vaccine containing genes from
  pathogen but will not cause infection

http//www.youtube.com/watch?vSduMbjW2V9A
http//highered.mcgraw-hill.com/olcweb/cgi/pluginp
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/120078/bio39.swf
26
Agricultural Applications

• Made plants more tolerable to our environment
• Resistance to weeds
• Added genes that would be harmful to insects and
  pests
• Increase nutritional value to some plants
• Ex adding vitamin A to rice in Asia

http//www.youtube.com/watch?vFTfuAbzAeB8
food http//www.youtube.com/watch?vJVIznPgdQSM
animals