3.5. genetic modification and cloning
TRANSCRIPT
3.5. Genetic modification and biotechnology
http://media.boingboing.net/wp-content/uploads/2012/01/pear.jpg
Miltiadis-Spyridon Kitsos
Platon IB Diploma
Genetic modification
The transfer of genes from one species to another. This will allow the
transformation of the recipients, having now new properties.
https://openclipart.org/image/2400px/svg_to_png/952
03/genetic-code-RNA.png
Remember that the genetic code is universal
TASK: Explain briefly this concept and its implications
In this sense a eukaryotic gene may be
transferred and expressed in a bacterium
Applications in medicine - insulin
http://proteopedia.org/wiki/index.php/Molecular_Playgrou
nd/Insulin
Insulin is a peptide hormone produced by the
beta-cells of the pancreas that regulates the
metabolism of carbohydrates.
regulates absorption of glucose from
the blood
the muscles,
fat cells
The Role of Insulin in the Human Body
https://www.youtube.com/watch?v=OYH1deu7-4E
Applications in medicine - insulin
Deficiency of insulin leads to
diabetes a group of metabolic
diseases characterized by increased
high blood sugar levels.
Diabetes type 1 absence of insulin
producing cells
Diabetes type 2 decreased
sensitivity of insulin receptors to
insulin.
https://commons.wikimedia.org/wiki/File:Diabetes_mellitus_world_map_-_DALY_-_WHO2004.svg#/media/File:Diabetes_mellitus_world_map_-_DALY_-_WHO2004.svg
Many diabetes patients require daily
administration of insulin (e.g., 30 minutes
before every meal)
https://upload.wikimedia.org/wikipedia/commons/d/d6/Insulin_pen.JPG
Applications in medicine - insulinIsolating the required gene sequence
Do you remember that eukaryotic genes have introns? (revision).
Bacteria do not have the enzyme powerhouse to remove introns. How we may insert
eukaryotic gene sequences in bacteria without introns?
Building a cDNA (complementary DNA) molecule
http://bio1510.biology.gatech.edu/wp-content/uploads/2012/11/cDNA_cloning.jpg http://highered.mheducation.com/sites/9834092339/student_view0/chapter18/cdna.html
Applications in medicine - insulinIsolating the required gene sequence
Use of restriction endonucleases
Enzymes of bacterial origin that cut
DNA molecules at a limited number of
specific locations.
The particular DNA sequences identified
by restriction enzymes are called
restriction sites
https://www.youtube.com/watch?v=aA5fyWJh5S0
Reece Campbell Biology 9th edition p. 394
Reece Campbell Biology 9th edition p. 394
Applications in medicine - insulin
Can we produce cheap insulin using biotechnology and genetic engineering?
http://www.di.uq.edu.au/sparq/images/proj4afig7.jpg
insulin gene
Bacterial plasmid (cloning vector)
“sticky ends”
https://2.bp.blogspot.com/_1IYomRKn1QM/TDx0eBTDmyI/AAAAAAAAABc/sbJf664uKKU/s1600/100000000000052F000003E8CBEA8CE5.jpg
Reece Campbell Biology 9th edition p. 394
Applications in medicine - insulin
Moving to industrial production
http://www.abpischools.org.uk/page/modules/diabetes_16plus/diabetes8.cfm?coSiteNavigation_allTopic=1
http://3.imimg.com/data3/UU/MY/MY-2056557/fermentor-bioreactor-design-500x500.png
https://ucdbiotech.files.wordpress.com/2009/09/roche_032.jpg?w=450
Moving beyond the production of insulin
Tumor necrosis factor. Treatment for
certain tumor cells
Interleukin-2 (IL-2). Cancer treatment,
immune deficiency, and HIV
Prourokinase. Treatment for heart attacks
Other major biotechnology products related
to medicine
https://www.youtube.com/watch?v=wYsaosI26oQ
http://highered.mheducation.com/sites/0072556781/student_view0/chapter31/animation_quiz_2.html
Taxol. Treatment for ovarian cancer
Interferon. Treatment for cancer and viral
infections
Genetically modified organismsGenetically modified or transgenic
Organisms that have been altered genetically by
the insertion of genes of other species so as to
add desirable properties.
http://learn.genetics.utah.edu/content/sci
ence/pharming/
Allott, Andrew, and David Mindorff. Biology: Course Companion. Oxford:
Oxford UP, 2010. 125. Print.
http://cls.casa.colostate.edu/transgeniccrops/animation.html
http://highered.mheducation.com/olcweb/cgi/plug
inpop.cgi?it=swf::535::535::/sites/dl/free/0072437
316/120078/bio40.swf::The+Ti+Plasmid
Genetically modified organisms
http://www.washingtonpost.com/blogs/wonkblog/files/2013/05/gm-crops-online-D-1.jpg
Some statistics
http://www.washingtonpost.com/blogs/wonkblog/files/2013/05/gm-crops-online-C-2.jpg
http://fstjournal.org/sites/default/files/imagepicker/21/G
M1_Pie_chart_Top_six_countries.jpg
http://sitemaker.umich.edu/sec006group5/files/this_map.jpg
Assessment of benefits and risks
BenefitsBenefits
Environmental
• Bt crops: less pesticides used.
• Increased shelf-life of fruits – decreased use and wastage.
• Reduced need for plowing and spraying thus reducing fuel consumption
Health
• Increased nutritionalvalue.
• No naturally-occuringallergens or toxins.
• Edible vaccines
Agricultures
• Increased resistance to drought, cold and salinity may expand cultivation range and yield.
• Facilitate the use of herbicides.
• Crops resistent to viruses.
http://www.ted.com/talks/pamela_ronald_the_case_for_engineering_our_food?language=en
Assessment of benefits and risks
BenefitsRisks
Environmental
• Toxins may affect not targeted organisms.
• Development of super resistant weeds by transfer of herbicide resistance genes.
• Reduction in biodiversity as food chains may be affected.
Health
• Proteins produced by introduced genes might be toxic or allergic to humans or livestock
• Development of antibiotic resistance genes
• Mutations not previously assessed.
Agricultures
• Accidental development of higher crop density can not be easily controlled.
• Development of toxin-resistant pests (natural selection)
• No strains adapted to local conditions may be developed.
https://www.youtube.com/watch?t=21&v=RQkQXyiynYs
The counter argument
The effect of GMOs – the case of Bt corn on
monarch butterflies.
https://www.youtube.com/watch?v=7Mcjnx8sVh8
https://upload.wikimedia.org/wikipedia/commons
/6/63/Monarch_In_May.jpg
In 1999 a a published research on the journal
Nature concluded that monarch butterfly
caterpillars are killed by the toxins produced
by Bt corn. Apparently, the caterpillars would
die when consuming the pollen grains of the
Bt corn deposited on the leaves of the
common milkweed.
http://www.fcps.edu/islandcreekes/ecology/Plants/Co
mmon%20Milkweed/6-12-15.jpg
The effect of GMOs – is it a controversy ?
In the 2001 the National Academy of Sciences published a major risk assessment study in the Proceedings of the National Academy of Sciences, which ran a series of articles evaluating the effects of biotech corn on monarch butterflies in the wild.
The conclusion of this research was the impact off Bt-corn’s impact on monarch butterfly populations is “negligible.”
http://www.geneticliteracyproject.org/2013/03/25/monsanto-v-monarch-butterflies/
http://www.geneticliteracyproject.org/2014/01/17/ted-talks-and-videos-on-the-science-of-gmos/
See also
The effect of GMOs – is it a controversy ?
In the 2001 the National Academy of Sciences published a major risk assessment study in the Proceedings of the National Academy of Sciences, which ran a series of articles evaluating the effects of biotech corn on monarch butterflies in the wild.
The conclusion of this research was the impact off Bt-corn’s impact on monarch butterfly populations is “negligible.”
http://www.geneticliteracyproject.org/2013/03/25/monsanto-v-monarch-butterflies/
http://www.geneticliteracyproject.org/2014/01/17/ted-talks-and-videos-on-the-science-of-gmos/
See also
Cloning
Clones are groups of genetically identical organisms or genetically identical cells
deriving from a single original parent cell.
https://youtu.be/KIpcCyuypzg
https://youtu.be/sOBvRhXIJN4
Bacterial binary fusion leads to the creation of
clones
See how the cleavage of
the blastocyst in humans.
http://multiples.about.com/library/photoga
l/photos/blgal68.jpg
Human monozygotic twins
are also clones
Natural methods of cloning
Plants
Garlic bulbs are genetically identical and originate from
one original bulb that grows into a small plant.
Strawberries grow plantlets which develop
their own roots and leaves. They may
become independent plants.
http://topveg.com/wp-content/uploads/2009/08/strawberry-plantlets.jpg
http://www.gardenseeker.com/herbs/images/Garlic%20-%20iStock_000018454020XSmall.jpg
Hydra a freshwater cnidarian is also
creating clones through budding (asexual
reproduction)
https://www.youtube.com/watch?v=ztPAGISkO7E
Natural methods of cloning
Plants
Garlic bulbs are genetically identical and originate from
one original bulb that grows into a small plant.
Strawberries grow plantlets which develop
their own roots and leaves. They may
become independent plants.
http://topveg.com/wp-content/uploads/2009/08/strawberry-plantlets.jpg
http://www.gardenseeker.com/herbs/images/Garlic%20-%20iStock_000018454020XSmall.jpg
Hydra a freshwater cnidarian is also
creating clones through budding (asexual
reproduction)
https://www.youtube.com/watch?v=ztPAGISkO7E
Animals
Cloning embryos in animals
A. It is possible to break down
animal embryos artificially.
B. The resulting cells are pluripotent
and may develop into new
embryos
C. New embryos are implanted into
surrogate mothers.
D. The main drawback of the
method is that only few clones
may be produced since embryo
cells loose their pluripotency
early on.
E. In most cases artificial cleavage
is induced at the 8-cell stage.
Cloning in Xenopus – Sir Robert Gurdon
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2315664/bin/jcb1810178f01.jpg
Sir Robert Gurdon
Nobel Prize in Medicine 2012
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Nd9GcS6VlpbeCpPWSALqcbSP
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1. Isolate tadpole cells
3. Isolate nuclei
2. Isolate tadpole egg cells and remove nuclei
Enucleated egg cell+
Egg cells containing somatic cell nuclei
Development of Xenopus tissues
http://www.pollywogsworldoffrogs.com/pollys/xenopus-tadpoles.jpg
Cloning Dolly the sheep
Dolly was the first domesticated animal to be cloned. Dolly was born in 1996 at RoslinInstitute in Scotland and died 6 years later in 2003 from lung disease.
https://youtu.be/tELZEPcgKkE
http://scholarblogs.emory.edu/philosophy316/files/2014/01/Dolly-Process.jpg
https://youtu.be/4kBVjwyx5VA
Cloning resources
http://learn.genetics.utah.edu/content/cloning/clickandclone/
1. Watch the process of enucleating an egg cell
2. An interactive animation on cloning
http://www.hhmi.org/biointeractive/somatic-cell-nuclear-transfer-video
3. Read the following article: “Human stem cells created by cloning”
http://www.nature.com/news/human-stem-cells-created-by-cloning-1.12983
Slides taken fromStephen Taylor’s