Changes

From Opengenome.net

Genetic engineering

25 bytes removed, 10:19, 4 November 2010
no edit summary
<p><strong>Genetic engineering</strong>, <strong>recombinant DNA technology</strong>, <strong>genetic modification/manipulation</strong> (<strong>GM</strong>) and <strong>gene splicing</strong> are terms that are applied to the manipulation of genes, generally implying that the process is outside the organism's natural reproductive process. It involves the isolation, manipulation and reintroduction of DNA into cells or model organisms, usually to express a protein to reach desired effects. The aim is to introduce new characteristics or attributes physiologically or physically, such as making a crop resistant to a herbicide, introducing a novel trait, enhancing existing ones, or producing a new protein or enzyme. Successful endeavours include the manufacture of human insulin through the use of modified bacteria, the manufacture of erythropoietin in Chinese hamster ovary cells, and the production of new types of experimental mice such as the OncoMouse (cancer mouse) for research.</p>
<p><strong>DEFINITION</strong>: <em>Genetic Engineering</em> is the scientific alteration of genes or genetic material to produce desirable new traits in organisms or to eliminate undesirable ones.</p>
<p>Since a protein sequence is specified by a segment of DNA called a gene, novel versions of that protein can be produced by changing the DNA sequence of the gene. There are a number of ways through which this could be achieved. After isolating a section of DNA that includes the gene, the gene or required portion of the gene is cut out. After modification of the sequence if necessary, it may be introduced (spliced) into a different DNA segment or into a vector for transformation into living cells. Daniel Nathans and Hamilton Smith received the 1978 Nobel Prize in Physiology or Medicine for their isolation of restriction endonucleases, which are able to cut DNA at specific sites. Together with ligase, which can join fragments of DNA together, restriction enzymes formed the initial basis of recombinant DNA technology. Some groups have argued<sup class="noprint Template-Fact"><span style="white-space: nowrap" title="This claim needs references to reliable sources since sources&nbsp;since March 2007" style="WHITE-SPACE: nowrap">[<em>citation needed</em>]</span></sup> that genetic engineering is wrong and is &quot;doing the work of God&quot;, but most scientists believe that genetic engineering is essential to help future medical discoveries<sup class="noprint Template-Fact"><span style="white-space: nowrap" title="This claim needs references to reliable sources since sources&nbsp;since May 2007" style="WHITE-SPACE: nowrap">[<em>citation needed</em>]</span></sup>. However, even with regard to this technology's great potential, scientists around the world have raised concerns about the introduction of genetically engineered plants and animals into the environment and the potential dangers of human consumption of GM foods. They say that these organisms have the potential to spread their modified genes into native populations thereby disrupting natural ecosystems. See also GM Food Controversies, and Genetically modified organism for more information on GM controversies. Professor Stephen Hawking defended the genetic enhancing of our species in order to compete with Artificial intelligence.<sup class="reference" id="_ref-0" class="reference"><font color="#800080">[1]</font><br />
</sup></p>
<p>&nbsp;</p>
<p>Now that the rapid sequencing of arbitrarily large genomes has become a simple, if not trivial affair, a much greater challenge will be elucidating function of the extraordinarily complex web of interacting proteins, dubbed the proteome, that constitutes and powers all living things. Genetic modification permits alteration of the primary structure of proteins and has therefore become a powerful tool in analyzing structure-function relationships in protein research. The use of the term &quot;genetic engineering&quot; to describe the experimental genetic modification of whole organisms, however, suggests a level of precision and an understanding of developmental biological principles beyond what has been achieved. Nonetheless, research progress has been made using a wide variety of techniques, including:</p>
<ul>
<li>Loss of function, such as in a knockout experiment, in which an organism is engineered to lack the activity of one or more genes. This allows the experimenter to analyze the defects caused by this mutation, and can be considerably useful in unearthing the function of a gene. It is used especially frequently in developmental biology. A knockout experiment involves the creation and manipulation of a DNA construct in vitro, which, in a simple knockout, consists of a copy of the desired gene which has been slightly altered such as to cripple its function. The construct is then taken up by embryonic stem cells, where the engineered copy of the gene replaces the organism's own gene. These stem cells are injected into blastocysts, which are implanted into surrogate mothers. Another method, useful in organisms such as Drosophila (fruit fly), is to induce mutations in a large population and then screen the progeny for the desired mutation. A similar process can be used in both plants and prokaryotes. </li> <li>Gain of function experiments, the logical counterpart of knockouts. These are sometimes performed in conjunction with knockout experiments to more finely establish the function of the desired gene. The process is much the same as that in knockout engineering, except that the construct is designed to increase the function of the gene, usually by providing extra copies of the gene or inducing synthesis of the protein more frequently. </li> <li>'Tracking' experiments, which seek to gain information about the localization and interaction of the desired protein. One way to do this is to replace the wild-type gene with a 'fusion' gene, which is a juxtaposition of the wild-type gene with a reporting element such as Green Fluorescent Protein (GFP) that will allow easy visualization of the products of the genetic modification. While this is a useful technique, the manipulation can destroy the function of the gene, creating secondary effects and possibly calling into question the results of the experiment. More sophisticated techniques are now in development that can track protein products without mitigating their function, such as the addition of small sequences which will serve as binding motifs to monoclonal antibodies. </li> <li>Expression studies aim to discover where and when specific proteins are produced. In these experiments the DNA sequence before the DNA that codes for a protein, known as a gene's promoter is reintroduced into an organism with the protein coding region replaced by a reporter gene such as GFP or an enzyme that catalyzes the production of a dye. Thus the time and place where a particular protein is produced can be observed. Expression studies can be taken a step further by altering the promoter to find which pieces are crucial for the proper expression of the gene and are actually bound by transcription factor proteins; this process is known as promoter bashing. </li>
</ul>
<p>&nbsp;</p>
<h2><span class="mw-headline">Reading list</span></h2>
<ul>
<li><cite class="book" style="FONTfont-STYLEstyle: normal" class="book">British Medical Association (1999). <em>The Impact of Genetic Modification on Agriculture, Food and Health</em>. BMJ Books. ISBN 0-7279-1431-6.</cite><span class="Z3988" title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=book&amp;rft.btitle=The+Impact+of+Genetic+Modification+on+Agriculture%2C+Food+and+Health&amp;rft.au=British+Medical+Association&amp;rft.date=1999&amp;rft.pub=BMJ+Books">&nbsp;</span> </li> <li><cite class="book" style="FONTfont-STYLEstyle: normal" class="book">Donnellan, Craig (2004). <em>Genetic Modification (Issues)</em>. Independence Educational Publishers. ISBN 1-86168-288-3.</cite><span class="Z3988" title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=book&amp;rft.btitle=Genetic+Modification+%28Issues%29&amp;rft.au=Donnellan%2C+Craig&amp;rft.date=2004&amp;rft.pub=Independence+Educational+Publishers">&nbsp;</span> </li> <li><cite class="book" style="FONTfont-STYLEstyle: normal" class="book">Morgan, Sally (2003). <em>Superfoods: Genetic Modification of Foods (Science at the Edge)</em>. Heinemann. ISBN 1-4034-4123-5.</cite><span class="Z3988" title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=book&amp;rft.btitle=Superfoods%3A+Genetic+Modification+of+Foods+%28Science+at+the+Edge%29&amp;rft.au=Morgan%2C+Sally&amp;rft.date=2003&amp;rft.pub=Heinemann">&nbsp;</span> </li> <li><cite class="book" style="FONTfont-STYLEstyle: normal" class="book">Smiley, Sophie (2005). <em>Genetic Modification: Study Guide (Exploring the Issues)</em>. Independence Educational Publishers. ISBN 1-86168-307-3.</cite><span class="Z3988" title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=book&amp;rft.btitle=Genetic+Modification%3A+Study+Guide+%28Exploring+the+Issues%29&amp;rft.au=Smiley%2C+Sophie&amp;rft.date=2005&amp;rft.pub=Independence+Educational+Publishers">&nbsp;</span> </li> <li><cite classstyle="bookfont-style: normal" id="Reference-Zaid-2001" styleclass="FONT-STYLE: normalbook">Zaid, A; H.G. Hughes, E. Porceddu, F. Nicholas (2001). <em>Glossary of Biotechnology for Food and Agriculture - A Revised and Augmented Edition of the Glossary of Biotechnology and Genetic Engineering. Available in English, French, Spanish and Arabic</em>. Rome, Italy: FAO. ISBN 92-5-104683-2.</cite><span class="Z3988" title="ctx_ver=Z39.88-2004&amp;rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&amp;rft.genre=book&amp;rft.btitle=Glossary+of+Biotechnology+for+Food+and+Agriculture+-+A+Revised+and+Augmented+Edition+of+the+Glossary+of+Biotechnology+and+Genetic+Engineering.+Available+in+English%2C+French%2C+Spanish+and+Arabic&amp;rft.aulast=Zaid&amp;rft.aufirst=A&amp;rft.date=2001&amp;rft.pub=%5B%5BFAO%5D%5D&amp;rft.place=%5B%5BRome%2C+Italy%5D%5D&amp;rft_id=http%3A%2F%2Fwww.fao.org%2Fbiotech%2Findex_glossary.asp">&nbsp;</span> </li>
</ul>
<p>&nbsp;</p>
<h2><span class="mw-headline">References</span></h2>
<ol class="references">
<li id="_note-0"><strong><font color="#800080">^</font></strong> apud Computerworld.com.au interview with Vernor Vinge - <em>AI will surpass human intelligence after 2020</em> </li>
</ol>
<p>&nbsp;</p>
<h2><span class="mw-headline">See also</span></h2>
<ul>
<li>Bioethics </li> <li>Cloning </li> <li>Ethics of technology </li> <li>Eugenics </li> <li><em>Genetic Roulette</em> (book) </li> <li>Genetically modified food </li> <li>Genetically modified organisms </li> <li>Human genetic engineering </li> <li>Ice-minus bacteria </li> <li>Monsanto </li> <li>Recombinant DNA </li> <li>Research ethics </li> <li><em>Seeds of Deception</em> (book) </li> <li>Stem cell </li> <li>Synthetic biology </li> <li>Transgenic Bacteria </li> <li>Paratransgenesis </li> <li>Gene pool </li> <li>Genetic Pollution </li> <li>Genetic Erosion </li>
<li>[[Biomatics]]</li>
</ul>
<h3><span class="mw-headline">General</span></h3>
<ul>
<li><a class="external text" title="http://www.drze.de/themen/blickpunkt/GHLhttp://www.drze.de/themen/blickpunkt/GHL-en?la=en-" rel="nofollow" href="http://www.drze.de/themen/blickpunkt/GHLhttp://www.drze.de/themen/blickpunkt/GHL-en?la=en-">In Focus &quot;Genetically modified foods:Technical and scientific aspects, ethical aspects and legal aspects&quot; (German Reference Centre for Ethics in the Life Sciences)</a> </li> <li><a class="external text" title="http://www.bbsrc.ac.uk/life/ingeneious/3_1/3_1_1.html" rel="nofollow" href="http://www.bbsrc.ac.uk/life/ingeneious/3_1/3_1_1.html">BBSRC - The science behind genetic modification</a> </li> <li><a class="external text" title="http://www.mfe.govt.nz/publications/organisms/royal-commission-gm/" rel="nofollow" href="http://www.mfe.govt.nz/publications/organisms/royal-commission-gm/">Ministry for the Environment NZ - Report of the Royal Commission on Genetic Modification</a> </li> <li><a class="external text" title="http://www.gmo-safety.eu/en/" rel="nofollow" href="http://www.gmo-safety.eu/en/">GMO Safety - Information about research projects on the biological safety of genetically modified plants.</a> </li> <li><a class="external text" title="http://www.rsrevision.com/Alevel/ethics/genetic_engineering/index.htm" rel="nofollow" href="http://www.rsrevision.com/Alevel/ethics/genetic_engineering/index.htm">Genetic Engineering</a> A UK site for students, with case studies and ethical responses </li> <li><a class="external text" title="http://www.bootstrike.com/Genetics/" rel="nofollow" href="http://www.bootstrike.com/Genetics/">Introduction to Genetic Engineering</a> Covers general information on Genetic Engineering including cloning, stem cells and DNA. </li>
<li>[http://biomatics.org Biomatics.org]</li>
</ul>
<h3><span class="mw-headline">News</span></h3>
<ul>
<li><a class="external text" title="http://www.defra.gov.uk/environment/gm/index.htm" rel="nofollow" href="http://www.defra.gov.uk/environment/gm/index.htm">DEFRA - Genetic Modification (GM)</a> </li> <li><a class="external text" title="http://news.bbc.co.uk/1/hi/sci/tech/6197768.stm" rel="nofollow" href="http://news.bbc.co.uk/1/hi/sci/tech/6197768.stm">BBC News - GM potato trials given go-ahead</a> - 01/12/06 </li> <li><a class="external text" title="http://www.brightsurf.com/news/headlines/31015/New_study_finds_genetically_engineered_crops_could_play_a_role_in_sustainable_agriculture.html" rel="nofollow" href="http://www.brightsurf.com/news/headlines/31015/New_study_finds_genetically_engineered_crops_could_play_a_role_in_sustainable_agriculture.html">Brightsurf Science News - New study finds genetically engineered crops could play a role in sustainable agriculture</a> - 06/08/07 </li>
</ul>
<!--
Maximum: 2048000 bytes
--><!-- Saved in parser cache with key enwiki:pcache:idhash:12383-0!1!0!default!!en!2 and timestamp 20070831220621 -->
<div class="printfooter">&nbsp;</div>
<p>&nbsp;</p>
0
edits

Navigation menu