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23 Cards in this Set
- Front
- Back
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selection of crops, animals over millenia |
ugh whatever there's not actually words |
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gmos |
transgenic plants, plants that are artificially engineered to contain genes from other plants or other species. applications: medical purposes, increased crop yield, pesticide resistance, improved product` |
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cholera? |
the bacteria produce enterotoxins that interact with the cell that line the intestines, the toxins activates an enzyme in the cell that leads to high levels of cAMP elevated cAMP levels cause water and salts to be pumped from cells into intestines, the toxin has one A1 subunit, one A2 subunit, and five B subunits: A/A2/B5, the A1 subunit is the part that raises cAMP levels, similar structure/activity for E coli labile-toxin
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labile toxin |
DNA for LT gene can be isolted and sepperated by size |
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strategy for cloning DNA |
PICTURE go look at it. Host cell chromosome, plasmid vector is removed from bacterial cell and cut with restriction anenzyme, LT gene, DNA to be cloned is cut with the same restriction enzyme, introduction into host cell, slection with antibiotic |
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two ways to get DNA into cells |
electroporation-plants given electric current to open up cell wall for intake of foerign DNA Biolistics- specific DA fragments attached to gold/tungsten particles are fired into cells at high speed with gene gun |
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inserting a new gene into plants |
gene idetified and isolated A: gene inserted into ti plasmid, bacterium mixed with plant cells, ti plasmid moves into plant clel and inserts DNA into plant chromosom, (a is for agrobacterium,) C screening for cells with transgee, cells screened for transgene transformed cells selected with selectable marker, transgenic plant regenerates from single transformed clell. B path- gene gun. gene replication, gold particles coated with DNA, cells shot with gene gun and DNA incroporated into plant cell chromosome, then c |
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Vaccine |
LT antigens in potatoes. studies done on rats and some showed increase in IgG: successful 1998, 14 human volunteers given varying amounts of potato tubers containing expression for LT antigen ~91% of volunteers had B-cells for LT after experiment decrease in 50% of antigen with boiling of potato |
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edible vaccines |
one way of generating edible vaccine relis on the bacterium agrobacterium tumefaciens to deliver into plant cells the genetic blueprint for viral or bacterial antigens, proteins that elicit a targeted immune response in the recipeient.
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edible vaccines diagram |
bacterial cell (antigen gene, plasmid, antibiotic esistance gene) put into thing with piece of leaf. (1. cut leaf) 2. expose leaf to bacteria carrying an antigen gene and an antibiotic-resistance gene. Allow bacteria to deliver the genes into leaf cells. (plant cell, (DNA, gene transfer bacterial cell,). 3. (antibiotic medium, dead cells, callus) 3.expose leaf to an antibiotic to kill cells that lack the new genes. wait for surviving (gene-altered) cells to multiply and form a clump (callus) 4. allow callus to sprout shoots and roots. 5. put in soil. Within three months, the plantles will grow into plants bearing antigen-laden vaccine potatoes. |
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alternative method to introduce DNA into plants |
agrobacterium tumefaciens is a bacterium commonly found in soil This bacteria can infect plant cells with a piece of its own DNA called T-DNA. This DNA causes tumors |
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mechanism of agrobacterium tumefaciens |
T-DNA integrates into the plant chromosomes tumor-causing genes on the T-DNA have been rmoved DNA sequence to be transferred to plant cell is fused to T-DNA |
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hericide resitant crops |
+CP4EPSPS gene=roundup ready. |
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what is roundup |
glyphosate. Glyphosate inhibits synthesis of essential amino acids: tryptophann, phenylalanine, tyrosine. Glyphosate binds to and inhibits the enzyme EPSPS. Animals do not usethis reaction to make these amino acids, so herbicide is specific for plants |
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Incorporation of Roundup Resistance into plants |
Mechanisms to provide glyphosate resistance 1. introdue EPSPS molecules that do not bind glyphosate 2. herbicide deactivation. Found bacterial gene-CP4-that produces a version of EPSPS that does not ind to lyphosate, but does bind to natural substrate. Introducing this gene into plants to give them roundup resistance |
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herbicide resistance |
current weed species with glyphsate resistance in the world -rigid ryegrass and italian rye grass, goosegrass, horsegrass. Solution: another herbicide will be applied or mixed with glyphosate Consequences: added cost, and perhpas added application, potential injury, which erode the benfits of the technology |
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BT corn v corn borer |
European corn borer is the most most damaging pest of corn throughout the united states and canada. Losses reulting from european corn borer damage and control costs exceed $1 bil ach year |
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european corn borer |
larval damage is hidden, heavy infestation are unpredictable, scouting multiple times each summer takes time and requires skill, insecticides are expensive and raise health or enviornmental concerns, benefits of european corn borer management are uncertain |
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bt toxin |
BT- naturally occuring soil bacterium, bt makes a toxin called cy proteins tht are insect stomach poison. They cause the cells in the stomach to burst. BT toxins are protoxins, the must be activated in insect sotmach to be toxic, thus only insects able to activate toxin will be sensitive to insecticide |
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mechanism of cry toxin |
1. ingestion of protoxin (a protein) 2. cut up protoxin to activate 3. interact with cell surface receptor 4. toxin undergoes conformational change 5. insertion of toxin into membranes forms a pore |
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creating transgenic BT crops picture 1 |
picture!! bacillius thuringiensis-> bt gene is inserted into crop->pest dies when feeding on any plant |
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creating bt crops picture 2 |
bt gene with enzymes around it->bt gene insertion into corn expression assette->lil green parts on either end, promoter and terminator->plasmid, vector with transgene multiplied in bacteria->??->foreign genes inserted into the corn cell genome->GM corn |
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potential problems with Bt crops? |
-harm to other organisms-pollen from Bt corn was shown to cuse high mortality rates in monarch butterfly larvae. BUT ffollow-up studies have shown that the exposure levels in the fields are negligible -transgenic genes may escape to related corn species: artificial DNA from transgenic corn has been detected in traditional corn varieties in remote areas of Mexico -Resistance: the EC and other pests may become resistant to Cry proteins
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