BIOL 1010 Lecture Notes - Lecture 7: Calcium Chloride, Huntingtin, Globin
20 Aug 2018
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lecture 7
DNA technology: the genetic revolution
Overview
- The technology
- The applications
- the implications
Technological revolutions
Genetic revolution is during our era
Technology and applications (techniques that involve DNA that are used)
1. Gene cloning
Dolly was the first mammal cloned
2. Production of pharmaceuticals
Some proteins are used to make pharmaceutical (gene cloning for the protein…)
3. Vaccines
Making vaccines with genes that help fight disease
4. DNA fingerprinting for forensics, animal and plant breeding, wildlife conservation and
management, etc.
forensic shows CSI: DNA finger printing
also useful for animal & plant breeding and wildlife conservation (extinction)
5. Transgenic organisms
Organisms that have genes that belong to another organism
6. Diagnosis of genetic disease and gene therapy
Illness that can be fixed by putting a protein in a body of a person that doesn’t produce it
The implications
Technology comes with a cost, controversial questions about these subjects:
1.Privacy of genetic information
Some people don’t want others to know their genetic information in their body
2.Pre-natal diagnosis of genetic disease & gene therapy
Recognizing disease of embryo in the mother’s body = cancelling the pregnancy
3.Safety of genetically engineered products and organisms; their impact on the environment &
consumers
GMO – specifically the ones that are genetically engineered – impacts on the environment and
consumers
lecture 7
Sticky ends
Bases that are left unpaired after the
cutting the restriction enzyme
“sticky”: can form hydrogen
bonded base pairs with
complementary sticky ends on
another DNA molecule
Fragment size
the resulting fragments after a
restriction enzyme is cut are the 3’
and the 5’ end from each side…
To count its size, you count the
number of base pairs
If there are sticky ends, 2 sticky
ends count as one base pair
Restriction enzymes
Found by Nathan and smith
Crucial to developing genetic engineering (in the tool box that a geneticist uses)
Function
Cut a specific sequence in the double stranded DNA molecule
Found in bacteria as an immune function
- use it to cut viral DNA inside their cell, their way of protecting themselves from invasive
virus = if they spot a viral DNA, they release their restriction enzymes to go cut up the
viral DNA so it can’t do its job of infecting the bacterial cell
- Don’t cut their own DNA because its protected by a methyl group
Can be used to cut up a specific double strand of DNA
Different types of restriction enzymes found in bacteria (over 6000 available for labs) –
Each is very specific where it cuts in the sequence
= specificity is what is useful to genetic engineer
Restriction site
The specific sequence (usually 4-8 nucleotide base pairs) in the nucleotide bases that the
restriction enzyme recognizes
Restriction fragments
The fragments left after the restriction enzyme has cut (see size below)
The tool box of a genetic engineer
What genetic engineers use
First item: restriction enzyme
Example 1 - restriction enzyme EcoRI
Finds a sequence in the unmethylated DNA and chops it off at a spot (same spot every time)
This specific enzyme cuts between the GA on the top and on the bottom when it recognizes
GAAT on the top DNA base
Left with the sticky ends: bases that are not paired
In this example, AATT from both fragments are sticky ends (only GC are based paired)
Example 2 – restriction enzyme BamHI
Cuts at a different specific place in the DNA sequence:
lecture 7
Example 2 – restriction enzyme BamHI and PstI
BamHI will cut at between the GC on the top and
the bottom
Ends up with over hanging sticky ends on the 5-
prime end
Another enzyme: PstI will cut at a different spot
This one cuts between AG on the top and bottom
Ends up with sticky ends on the 3-prime end
These sticky ends are complimentary base pairs
Detour: Nomenclature of restriction enzymes
They are named after the bacteria which they are isolated from
EcoRI
Found in the bacteria E. Coli
Found in the strain R…
Found in the 1endonuclease I
3,000 different restriction enzymes found so far
600 used commercially in the lab by genetic enginneers
DIFFERENT RESTRICTION ENZYMES CUT AT
DIFFERENT DNA SEQUENCES
Document Summary
Technology and applications (techniques that involve dna that are used: gene cloning. Dolly was the first mammal cloned: production of pharmaceuticals. Some proteins are used to make pharmaceutical (gene cloning for the protein : vaccines. Organisms that have genes that belong to another organism: diagnosis of genetic disease and gene therapy. Illness that can be fixed by putting a protein in a body of a person that doesn"t produce it. Technology comes with a cost, controversial questions about these subjects: Some people don"t want others to know their genetic information in their body. 2. pre-natal diagnosis of genetic disease & gene therapy. Recognizing disease of embryo in the mother"s body = cancelling the pregnancy. 3. safety of genetically engineered products and organisms; their impact on the environment & consumers. Gmo specifically the ones that are genetically engineered impacts on the environment and consumers lecture 7. Crucial to developing genetic engineering (in the tool box that a geneticist uses)
