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| − |
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| − |
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| − |
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| − | <div class="group center">
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| − | <br>
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| − | <img src="https://static.igem.org/mediawiki/2015/0/04/TLSE_Attract_fig1.png" />
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| − | </div>
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| − | <div id="part1"></div><!-- ANCHOR 1 -->
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| − | <div class="group center">
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| − | <br>
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| − | <p>Figure 1 : <i>Varroa destructor</i> life cycle,
| |
| − | adapted from B. Alexander</p>
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| − | </div>
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| − |
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| − | <div>
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| − |
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| − | <div class="subtitle" >
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| − | <h3>How to attract varroa</h3>
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| − | </div>
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| | | | |
| − |
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| − | <div class="group center">
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| − | <p align="justify" style="font-size:15px;">
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| − |
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| − | Just before capping, bee larvaes produce a wide range of molecules,
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| − | those molecules warn the mite about the upcoming capping and motivate
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| − | it to enter the cell [2].
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| − | Of all these molecule, scientific studies have shown that one can
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| − | significantly attract varroa:
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| − | <i>butyrate</i> [3].
| |
| − | </p>
| |
| − | </div>
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| − |
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| − |
| |
| − |
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| − | <div class="group center">
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| − | <div class="one_half first">
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| − | <p align="justify" style="font-size:15px;">
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| − | <br>
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| − | Butyrate is a volatile acid which is non-toxic for honeybees
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| − | nor the human being, because it is already present at physiologic
| |
| − | concentrations in the digestive tract. Moreover this molecule
| |
| − | is naturally
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| − | produced by some bacterial strains like <i>Clostridium</i>,
| |
| − | which is an asset
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| − | for this synthetic biology project [4].</p><div id="part2"></div> <!-- ANCHOR 2 --><p align="justify" style="font-size:15px;"> Therefore we decided to
| |
| − | modify Apicoli
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| − | so it will synthesize
| |
| − | butyrate in order to attract varroa.
| |
| − | </p>
| |
| − | </div>
| |
| − |
| |
| − | <div class="one_half">
| |
| − |
| |
| − | <img src="https://static.igem.org/mediawiki/2015/e/e6/TLSE_Attract_fig2.png">
| |
| − | <p>Figure 2: Results of butyrate attraction
| |
| − | test with quadrants method
| |
| − | </p>
| |
| − |
| |
| − | </div>
| |
| − | </div>
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| − |
| |
| − | <div class="subtitle" >
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| − | <h3>Butyrate attraction test</h3>
| |
| − | </div>
| |
| − |
| |
| − |
| |
| − | <div class="group center"> <!-- FIRST PARAGRAPH -->
| |
| − |
| |
| − | <div class="one_half first">
| |
| − |
| |
| − | <img src="https://static.igem.org/mediawiki/2015/b/b8/TLSE_Attract_fig3.png">
| |
| − | <p>Figure 3: Butyrate attraction test using
| |
| − | T tube, with varroa mite in the middle
| |
| − |
| |
| − | </p>
| |
| − | </div>
| |
| − |
| |
| − | <div class="one_half">
| |
| − | <p align="justify" style="font-size:15px;">
| |
| − | To check adequacy and relevance of this study (Figure 2),
| |
| − | an experiment using a T-tube has been developed (Figure 3).
| |
| − | In the first branch, there is a cotton soaked with 50 µL of water,
| |
| − | in the second a cotton with 50 µL of butyrate at 4%, and finally the
| |
| − | last one contains the varroa.</p> <div id="part3"> <!-- ANCHOR 3 --> </div> <p align="justify" style="font-size:15px;">The butyrate being very volatile, our
| |
| − | system
| |
| − | used a pump to renew air, producing a concentration gradient.
| |
| − | </p>
| |
| − | </div>
| |
| − |
| |
| − | </div>
| |
| − |
| |
| − | <div class="subtitle" >
| |
| − | <h3>How to produce butyrate with <i>E.coli</i>?</h3>
| |
| − | </div>
| |
| − |
| |
| − | <div class="group center">
| |
| − |
| |
| − | <p align="justify" style="font-size:15px;">
| |
| − | In this project, an <i>Escherichia coli</i> strain is used for its known
| |
| − | simplicity of genetic manipulation and its adequacy with butyrate
| |
| − | synthesis. Indeed, among the five enzymes of the butyrate pathway,
| |
| − | two enzymes are naturally produced by the bacteria. The following
| |
| − | engineered butyrate pathway has been designed:
| |
| − | </p> <br>
| |
| − | </div>
| |
| − |
| |
| − |
| |
| − | <div class="group center"> <!-- CENTERED FIGURE -->
| |
| − | <img src="https://static.igem.org/mediawiki/2015/0/02/TLSE_Attract_fig4.png" />
| |
| − | </div>
| |
| − | <div class="group center">
| |
| − | <figcaption>Figure 4: Engineered butyrate pathway</figcaption>
| |
| − |
| |
| − | </div>
| |
| − |
| |
| − | <div class="group center">
| |
| − |
| |
| − | <p align="justify" style="font-size:15px;">
| |
| − | <br>
| |
| − | The initial substrate is glucose which is decomposed into
| |
| − | acetyl-CoA during glycolysis. Finally, butyrate pathway
| |
| − | begin with acetyl-CoA: five genes are required with two
| |
| − | homologous and three heterologous genes.
| |
| − | </p>
| |
| − |
| |
| − | </div>
| |
| − | <br>
| |
| − |
| |
| − |
| |
| − | <div style="font-size:15px;">
| |
| − | <ul>
| |
| − | <li><b><i>atoB</i></b> present in <i>E.coli</i>, coding for acetyl-CoA
| |
| − | acetyltransferase, an acetyltransferase catalyzing the combination
| |
| − | of two acetyl-CoA.
| |
| − | <br>
| |
| − | <div class="group center">
| |
| − | <br>
| |
| − | <img src="https://static.igem.org/mediawiki/2015/c/c5/TLSE_Attract_fig5.png" />
| |
| − | </div>
| |
| − | <div class="group center">
| |
| − | <br>
| |
| − | <p class="legend">Figure 5: Reaction catalyzed by acetyl-CoA
| |
| − | acetyltransferase </p>
| |
| − | </div>
| |
| − |
| |
| − | </li>
| |
| − |
| |
| − | <li><b><i>hbd</i></b> present in <i>Clostridium acetobutylicum</i> coding for
| |
| − | 3-hydroxybutyryl-CoA dehydrogenase, an oxidoreductase catalyzing
| |
| − | the formation of an alcohol function.
| |
| − | <br>
| |
| − | <div class="group center">
| |
| − | <br>
| |
| − | <img src="https://static.igem.org/mediawiki/2015/d/d6/TLSE_Attract_fig6.png" />
| |
| − | </div>
| |
| − | <div class="group center">
| |
| − | <br>
| |
| − | <p class="legend">Figure 6: Reaction catalyzed by
| |
| − | 3-hydroxybutyryl-CoA dehydrogenase
| |
| − | </p>
| |
| − | </div>
| |
| − | </li>
| |
| − |
| |
| − | <li><b><i>crt</i></b> present in <i>C.acetobutylicum</i>
| |
| − | coding for 3-hydroxybutyryl-CoA dehydratase,
| |
| − | a lyase cleaving carbon-oxygen bond.
| |
| − | <br>
| |
| − | <div class="group center">
| |
| − | <br>
| |
| − | <img src="https://static.igem.org/mediawiki/2015/6/67/TLSE_Attract_fig7.png" />
| |
| − | </div>
| |
| − | <div class="group center">
| |
| − | <br>
| |
| − | <p class="legend">Figure 7:
| |
| − | Reaction catalyzed by 3-hydroxybutyryl-CoA deshydratase
| |
| − |
| |
| − | </p>
| |
| − | </div>
| |
| − | </li>
| |
| − |
| |
| − | <li><b><i>ccr</i></b> present in
| |
| − | <i>Streptomyces collinus</i> coding
| |
| − | for crotonyl-CoA reductase,
| |
| − | an oxidoreductase acting on
| |
| − | CH=CH double bond. This enzyme
| |
| − | is also in <i>C.acetobutylicum</i> with
| |
| − | <b>bcd</b> gene coding for butyryl-CoA dehydrogenase,
| |
| − | with the disadvantage
| |
| − | to run with Electron Transfer
| |
| − | Flavoprotein (ETF) which complicates the reaction [6].
| |
| − | <br>
| |
| − | <div class="group center">
| |
| − | <br>
| |
| − | <img src="https://static.igem.org/mediawiki/2015/5/57/TLSE_Attract_fig8.png" />
| |
| − | </div>
| |
| − | <br>
| |
| − | <div class="group center">
| |
| − | <br>
| |
| − | <p class="legend">Figure 8: Reaction
| |
| − | catalyzed by crotonyl-CoA reductase
| |
| − | </p>
| |
| − | </div>
| |
| − |
| |
| − | </li>
| |
| − |
| |
| − | <li><b><i>tesB</i></b> present in <i>E.coli</i>
| |
| − | coding for acyl-CoA transferase 2,
| |
| − | a thiolase which enables coenzyme A transfer.
| |
| − | <br>
| |
| − | <div class="group center">
| |
| − | <br>
| |
| − | <img src="https://static.igem.org/mediawiki/2015/3/34/TLSE_Attract_fig9.png" />
| |
| − | </div>
| |
| − | <div class="group center">
| |
| − | <br>
| |
| − | <p class="legend">Figure 9: Reaction
| |
| − | catalyzed by acyl-CoA transferase 2
| |
| − | </p>
| |
| − | </div>
| |
| − |
| |
| − | </li>
| |
| − |
| |
| − | </ul>
| |
| − |
| |
| − | </div>
| |
| − |
| |
| − | <!-- ################################################################################################ -->
| |
| − | <!-- / container body -->
| |
| − | <div class="clear"></div>
| |
| | </main> | | </main> |
| | </div> | | </div> |
