Team:Toulouse/Project/Spreading

From 2014.igem.org

(Difference between revisions)
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<p class="texte">These two first characteristics of SubtiTree show that it is an annual bacterium, which can only grow in sap tree. By combinind them, they prevent any long term colonization of an ecological niche by SubtiTree against wild type bacteria. These prevent a long term effect.</p>
<p class="texte">These two first characteristics of SubtiTree show that it is an annual bacterium, which can only grow in sap tree. By combinind them, they prevent any long term colonization of an ecological niche by SubtiTree against wild type bacteria. These prevent a long term effect.</p>
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<p class="title1">Gene transfer</p>
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<p class="texte"> While we were trying to respond to bacterial spreading problem, at the same time we wondered about horizontal gene transfer. The transmission of genes from our synthetic bacterium to wild type bacteria could be blocked with two modifications. 
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First, as used in genetic engineering, plasmids are a tremendous way to transfer some genic information. In this way, it is not the best way to restrict the collecting transgenic DNA. That is why we inserted our genes in the bacterium chromosome.
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</p>
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<p class="texte">Secondly, some bacteria are able to accept chromosomal DNA, like <I>Bacillus subtilis</I>. Thus, the previous strategy is  not efficient enough to prevent transfer. We could include the toxin/anti-toxin system. The toxin gene is near our synthetic gene, contrary to the anti-toxin gene. So if there is a transfer of our synthetic gene, the toxin gene will be included in the transfer. Receiver bacteria will die by the production of the toxic protein. </p>
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<p class="texte">Our synthetic genes are not the only problem in the design of SubtiTree. One of the side effects of our cloning method is the persistence of antibiotic resistance genes. This is incompatible with the introduction of SubtiTree in the environment. It is possible to delete this resistance in chromosome. To conclude, the spreading limitation shown previously makes the use of SubtiTree acceptable in the environment.
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</p>
<p class="title1">Using a toxin-antitoxin system</p>
<p class="title1">Using a toxin-antitoxin system</p>
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All our constructions are carried by integrative plasmids. Consequently, our different genetic modules would be integrated into the bacterium genome. The integration in the genome is more stable as the constructions are less likely to be transferred to other microorganisms. In addition to that, the expression of our genetic modules would not be dependant on a selective pressure based on an antibiotic resistance (as we can not inject antibiotics in the tree), allowing a high level of transcription in planta.  
All our constructions are carried by integrative plasmids. Consequently, our different genetic modules would be integrated into the bacterium genome. The integration in the genome is more stable as the constructions are less likely to be transferred to other microorganisms. In addition to that, the expression of our genetic modules would not be dependant on a selective pressure based on an antibiotic resistance (as we can not inject antibiotics in the tree), allowing a high level of transcription in planta.  
</p>
</p>
-
 
-
 
-
<p class="title1">Gene transfer</p>
 
-
 
-
<p class="texte"> While we were trying to respond to bacterial spreading problem, at the same time we wondered about horizontal gene transfer. The transmission of genes from our synthetic bacterium to wild type bacteria could be blocked with two modifications. 
 
-
First, as used in genetic engineering, plasmids are a tremendous way to transfer some genic information. In this way, it is not the best way to restrict the collecting transgenic DNA. That is why we inserted our genes in the bacterium chromosome.
 
-
</p>
 
-
 
-
<p class="texte">Secondly, some bacteria are able to accept chromosomal DNA, like <I>Bacillus subtilis</I>. Thus, the previous strategy is  not efficient enough to prevent transfer. We could include the toxin/anti-toxin system. The toxin gene is near our synthetic gene, contrary to the anti-toxin gene. So if there is a transfer of our synthetic gene, the toxin gene will be included in the transfer. Receiver bacteria will die by the production of the toxic protein. </p>
 
-
 
-
<p class="texte">Our synthetic genes are not the only problem in the design of SubtiTree. One of the side effects of our cloning method is the persistence of antibiotic resistance genes. This is incompatible with the introduction of SubtiTree in the environment. It is possible to delete this resistance in chromosome. To conclude, the spreading limitation shown previously makes the use of SubtiTree acceptable in the environment.
 
-
</p>
 
-
 

Revision as of 10:19, 13 October 2014