Team:Penn/Project

From 2013.igem.org

(Difference between revisions)
Line 55: Line 55:
     <div class="section1"><!--page wrapper-->
     <div class="section1"><!--page wrapper-->
         <div class="text"><!--white text box-->
         <div class="text"><!--white text box-->
-
                <h2>ABSTRACT</h2> <!--title-->
+
              <p><strong>Background</strong><br />
-
                <p>The code of life is much more than a sequence of A's, G's, C's and T's;
+
  DNA methylation impacts many cellular processes including cell  differentiation, genomic imprinting, DNA replication, X chromosome  inactivation, and suppression of unneeded transcription from oncogenes. <br />
-
        a suite of epigenetic mechanisms, ranging from chromatin remodeling to non-coding RNAs,
+
  <img src="../AppData/Roaming/Adobe/Dreamweaver CS5.5/en_US/OfficeImageTemp/clip_image002.jpg" alt="" width="181" height="88" hspace="12" align="left" /><br />
-
        affect gene expression and cellular function. <div class="figure-wrap" style="margin-left: 200px;"><img class="figure" src="https://googledrive.com/host/0B4ZBZOYYKBzEeG5XLTdURjc0aTA" "/>
+
  <img src="../AppData/Roaming/Adobe/Dreamweaver CS5.5/en_US/OfficeImageTemp/clip_image004.jpg" alt="" width="174" height="48" hspace="12" align="left" /></p>
-
        <img class="figure" src="https://googledrive.com/host/0B4ZBZOYYKBzEeG05enR0ZFFXeEE" />
+
<p>&nbsp;</p>
-
        <img class="figure" src="https://googledrive.com/host/0B4ZBZOYYKBzEXzVMY3EtX284cTA" /></div>
+
<p>&nbsp;</p>
-
        <p> In particular, DNA methylation has been
+
<p>For example, this is CopyCat: <br />
-
        shown to alter transcriptional activity in a powerful, heritable mannerAbnormal methylation
+
<img src="../AppData/Roaming/Adobe/Dreamweaver CS5.5/en_US/OfficeImageTemp/clip_image006.png" alt="" width="169" height="255" hspace="12" align="left" /></p>
-
        patterns are associated with diseases including immunodeficiency syndromes, neurodevelopmental
+
<p>&nbsp;</p>
-
        disorders, and many types of cancer. Comprehensive understanding and control of DNA methylation
+
<p>&nbsp;</p>
-
        could be invaluable to researchers studying these diseases.</p>
+
<p>&nbsp;</p>
-
     
+
<p>                         <br />
-
       
+
  </p>
-
        <p>Synthetic biologists and geneticists are accustomed to turning genes on and off at will,
+
<p>&nbsp;</p>
-
        but the tools don’t exist to easily manipulate epigenetic patternsWe are developing a novel
+
<p>&nbsp;</p>
-
        fusion protein that enables site-specific methylation, which can repress promoter activity with
+
<p>&nbsp;</p>
-
        high precision. <div class="figure-wrap" style="float: center;"><img src="https://googledrive.com/host/0B4ZBZOYYKBzEdmZMalozd0pkSjg" style="height: 75px; margin: 5px; float: left;"/>
+
<p>CopyCat is the first cloned pet,  born in December 2001 (Shin, Taeyoung, et al. (2002)), and this is Rainbow:<br />
-
        <img src="https://googledrive.com/host/0B4ZBZOYYKBzEdlExOEgtVlZYYUU" style="height: 75px; float: left; margin: 5px;"/></div><p>In coming years, this fusion protein could become a powerful tool for epigenetics
+
  <img src="../AppData/Roaming/Adobe/Dreamweaver CS5.5/en_US/OfficeImageTemp/clip_image008.png" alt="" width="173" height="156" /><br />
-
        researchers looking to perform on/off studies in the vein of classical genetics, as well as an
+
  Rainbow is CopyCat&rsquo;s genetic  donor; note that they have totally different fur patterns – this is due to  their epigenetic differences, particularly a phenomenon called X-Chromosome  inactivation. This is a dosage compensation mechanism for females wherein one X  chromosome in each cell is randomly selected for inactivation by DNA  methylation and other modifications.</p>
-
        orthogonal mode of repressing constitutive promoters for bacterial synthetic biologists.
+
<p><br />
-
        Eventually, it could even give clinical researchers the means to restore healthy methylation
+
  DNA methylation also has another important effect in  mammalian cells; methylation of CpG sites can function to repress gene  expression, as shown where methylation prevents binding of DNA polymerase  upstream of a promoter, which is then silenced. <br />
-
        levels in many insofar-untreatable epigenetic diseases.</p>
+
  <img width="369" height="237" src="../AppData/Roaming/Adobe/Dreamweaver CS5.5/en_US/OfficeImageTemp/clip_image010.jpg" align="left" hspace="12" alt="Description: Screen Shot 2013-08-26 at 2.20.24 PM.png" /></p>
-
        <img src="https://googledrive.com/host/0B4ZBZOYYKBzEMzM5dWpRQWNvb1k" style="height: 75px; display: inline; float: right; margin: 5px;"/>
+
<p>&nbsp;</p>
-
        <img src="https://googledrive.com/host/0B4ZBZOYYKBzEek95VVUyMkltSHc" style="height: 75px; float: right; margin: 5px; "/>
+
<p>&nbsp;</p>
 +
<p>&nbsp;</p>
 +
<p>&nbsp;</p>
 +
<p>&nbsp;</p>
 +
<p>&nbsp;</p>
 +
<p>Clearly, DNA methylation is one of nature&rsquo;s most powerful mechanisms for transcriptional regulation, yet synthetic biologists don&rsquo;t talk  about it. Penn iGEM is adding synthetic biology as a tool for epigenetics researchers; we are providing researchers with the tools they need to safely and precisely engineer the epigenome. </p>
 +
<p><br />
 +
  <strong>Targeted Methylation:  the Possibilities</strong><br />
 +
  If the tools existed to allow researchers to target specific  DNA sequences for selective methylation, they could be used to inactivate  strong promoters (permanent repression without gene knockout), repress  overactive oncogenes, inactivate excess chromosomes, correct hypomethylation in  imprinting disorders and even control differentiation in stem cells. <br />
 +
  Our team aimed to address this need by creating a target methylation toolkit which includes a modular plasmid that enables fast, cheapand simple screening of targeted methyltransferases. </p>
 +
<p><strong>MaGellin: A one plasmid system for screening targeted  methyltransferases</strong><br />
 +
  <img src="../AppData/Roaming/Adobe/Dreamweaver CS5.5/en_US/OfficeImageTemp/clip_image012.png" alt="" width="290" height="290" hspace="12" align="left" /></p>
 +
<p>&nbsp;</p>
 +
<br clear="all" />
 +
<p>&nbsp;</p>
 +
<p>MaGellin has several key features: </p>
 +
<ol>
 +
  <li>DNA  binding domain/methyltransferase can be swapped out</li>
 +
  <li>Easy  digest assays both components: methylation and targeting</li>
 +
  <li>Inducible  system for controlled expression of protein</li>
 +
  <li>Verified  working bisulfite sequencing primers</li>
 +
</ol>
 +
<p>Restriction digest of miniprep screens targeted  methyltransferase efficacy<br />
 +
  <img width="139" height="446" src="../AppData/Roaming/Adobe/Dreamweaver CS5.5/en_US/OfficeImageTemp/clip_image014.jpg" alt="Description: One Plasmid System.jpg" /></p>
 +
<p>This assay gives Results 3 hours after miniprep. Bisulfite  sequencing would take 5 days and much more money.</p>
 +
<br clear="all" />
 +
<p>The following table compares bisulfite sequencing (the  currently used standard for measuring DNA methylation) to Magellin.</p>
 +
<table border="1" cellspacing="0" cellpadding="0" width="602">
 +
  <tr>
 +
    <td width="200" valign="top"></td>
 +
    <td width="201" valign="top"><p><strong>Bisulfite Sequencing</strong></p></td>
 +
    <td width="201" valign="top"><p><strong>Modular Plasmid</strong></p></td>
 +
  </tr>
 +
  <tr>
 +
    <td width="200" valign="top"><p>Time after Sample Collection</p></td>
 +
    <td width="201" valign="top" bgcolor="#FF0000"><p>5 days</p></td>
 +
    <td width="201" valign="top" bgcolor="#00FF00"><p>2 hours</p></td>
 +
  </tr>
 +
  <tr>
 +
    <td width="200" valign="top"><p>Cost</p></td>
 +
    <td width="201" valign="top" bgcolor="#FF0000"><p>$$$</p></td>
 +
    <td width="201" valign="top" bgcolor="#00FF00"><p>$</p></td>
 +
  </tr>
 +
  <tr>
 +
    <td width="200" valign="top"><p>Reports On-Target and Off-Target Effects</p></td>
 +
    <td width="201" valign="top" bgcolor="#00FF00"><p>Requires separate assays</p></td>
 +
    <td width="201" valign="top" bgcolor="#00FF00"><p>Can be assayed simultaneously</p></td>
 +
  </tr>
 +
  <tr>
 +
    <td width="200" valign="top"><p>Quantitative Measurement of Methylation</p></td>
 +
    <td width="201" valign="top" bgcolor="#00FF00"><p>Yes</p></td>
 +
    <td width="201" valign="top" bgcolor="#00FF00"><p>No</p></td>
 +
  </tr>
 +
  <tr>
 +
    <td width="200" valign="top"><p>Ease of Designing Sequencing Primers</p></td>
 +
    <td width="201" valign="top" bgcolor="#FF0000"><p>Difficult</p></td>
 +
    <td width="201" valign="top" bgcolor="#00FF00"><p>Primers already designed</p></td>
 +
  </tr>
 +
  <tr>
 +
    <td width="200" valign="top"><p>Ease of Cloning</p></td>
 +
    <td width="201" valign="top" bgcolor="#FF0000"><p>Must either co-transform or design cloning plan for    single-plasmid system</p></td>
 +
    <td width="201" valign="top" bgcolor="#00FF00"><p>Backbone with target is ready for cloning</p></td>
 +
  </tr>
 +
</table>
 +
<p><strong>Our team used  MaGellin to Characterize Existing and Novel Targeted Methyltransferases:</strong></p>
         </div>
         </div>
          
          

Revision as of 01:22, 25 September 2013

Project

team

Background
DNA methylation impacts many cellular processes including cell differentiation, genomic imprinting, DNA replication, X chromosome inactivation, and suppression of unneeded transcription from oncogenes.

 

 

For example, this is CopyCat:

 

 

 

                        

 

 

 

CopyCat is the first cloned pet, born in December 2001 (Shin, Taeyoung, et al. (2002)), and this is Rainbow:

Rainbow is CopyCat’s genetic donor; note that they have totally different fur patterns – this is due to their epigenetic differences, particularly a phenomenon called X-Chromosome inactivation. This is a dosage compensation mechanism for females wherein one X chromosome in each cell is randomly selected for inactivation by DNA methylation and other modifications.


DNA methylation also has another important effect in mammalian cells; methylation of CpG sites can function to repress gene expression, as shown where methylation prevents binding of DNA polymerase upstream of a promoter, which is then silenced.
Description: Screen Shot 2013-08-26 at 2.20.24 PM.png

 

 

 

 

 

 

Clearly, DNA methylation is one of nature’s most powerful mechanisms for transcriptional regulation, yet synthetic biologists don’t talk about it. Penn iGEM is adding synthetic biology as a tool for epigenetics researchers; we are providing researchers with the tools they need to safely and precisely engineer the epigenome.


Targeted Methylation: the Possibilities
If the tools existed to allow researchers to target specific DNA sequences for selective methylation, they could be used to inactivate strong promoters (permanent repression without gene knockout), repress overactive oncogenes, inactivate excess chromosomes, correct hypomethylation in imprinting disorders and even control differentiation in stem cells.
Our team aimed to address this need by creating a target methylation toolkit which includes a modular plasmid that enables fast, cheap, and simple screening of targeted methyltransferases.

MaGellin: A one plasmid system for screening targeted methyltransferases

 


 

MaGellin has several key features:

  1. DNA binding domain/methyltransferase can be swapped out
  2. Easy digest assays both components: methylation and targeting
  3. Inducible system for controlled expression of protein
  4. Verified working bisulfite sequencing primers

Restriction digest of miniprep screens targeted methyltransferase efficacy
Description: One Plasmid System.jpg

This assay gives Results 3 hours after miniprep. Bisulfite sequencing would take 5 days and much more money.


The following table compares bisulfite sequencing (the currently used standard for measuring DNA methylation) to Magellin.

Bisulfite Sequencing

Modular Plasmid

Time after Sample Collection

5 days

2 hours

Cost

$$$

$

Reports On-Target and Off-Target Effects

Requires separate assays

Can be assayed simultaneously

Quantitative Measurement of Methylation

Yes

No

Ease of Designing Sequencing Primers

Difficult

Primers already designed

Ease of Cloning

Must either co-transform or design cloning plan for single-plasmid system

Backbone with target is ready for cloning

Our team used MaGellin to Characterize Existing and Novel Targeted Methyltransferases: