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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>Master genes control basic body plans :: DNA from the Beginning</title> <meta name="description" content="Fruit fly mutaitons provided keys to understanding the molecular basis of large-scale developmental plans." /> <link rel="preload" as="style" src="/css/main.css"> <link rel="preload" as="script" src="/js/swfobject.js"> <link rel="preload" as="script" src="/js/prototype-1.6.1.js"> <link href="/css/main.css" rel="stylesheet" type="text/css" /> <link href='https://fonts.googleapis.com/css?family=Droid+Serif' rel='stylesheet' type='text/css'/> <link href='https://fonts.googleapis.com/css?family=Droid+Sans' rel='stylesheet' type='text/css'/> <script type="text/javascript" src="/js/swfobject.js"></script> <script type="text/javascript" src="/js/prototype-1.6.1.js"></script> </head> <body> <div id="container"> <div id="content"> <div id="header"> <div class="rollover-home"> <a href="/" class="rollover-home" title="DNA from the Beginning Home"><span class="displace">Home</span></a> </div> </div>  <div id="content-container"> <h1><span> Concept 37</span> Master genes control basic body plans.</h1> <div id="nav"> <ul> <li class="menu1"><a href="index.html" title="CONCEPT" ><span class="displace">CONCEPT</span></a></li> <li class="menu2"><a href="animation.html" title="ANIMATION"><span class="displace">ANIMATION</span></a></li> <li class="menu3"><a href="gallery.html" title="GALLERY"><span class="displace">GALLERY</span></a></li> <li class="menu4"><a href="av.html" title="VIDEO"><span class="displace">VIDEO</span></a></li> <li class="menu5"><a href="bio.html" title="BIO"><span class="displace">BIO</span></a></li> <li class="menu6"><a href="problem.html" title="PROBLEM"><span class="displace">PROBLEM</span></a></li> <li class="menu7"><a href="links.html" title="LINKS" ><span class="displace">LINKS</span></a></li> </ul> <br class="clearfloat" /> </div> <div id="concept"> <img src="/images/37/concept37.jpg" class="concept-image" alt="Master genes control basic body plans." /> <p>The development of an organism — from a fertilized egg, through embryonic and juvenile stages, to adulthood — requires the coordinated expression of sets of genes at the proper times and in the proper places. Studies of several bizarre mutations in the fruitfly, <em>Drosophila</em>, provided keys to understanding the molecular basis of large-scale developmental plans. Early embryonic genes express proteins that set up the orientation and define the body segments of the fly embryo. Then "homeotic" genes act on the segments to make the body parts distinct to each segment. </p> <p>Sequence analysis showed that homeotic genes from <em>Drosophila</em> and vertebrate animals share a 180-nucleotide region, called the homeobox. These homeobox proteins have structures highly similar to the regions of regulatory proteins that bind to DNA promoters and enhancers. Thus, a homeotic protein elicits coordinated expression when the protein binds to a specific promoter or enhancer sequence shared by a number of genes involved in the development of body region or segment.</p> </div> </div> <br class="clearfloat" /> <div id="footer"> <ul> <li><a href="/">Home</a></li> <li><a href="/sitemap.html">Site Map</a></li> <li><a href="/scientists.html">Scientists</a></li> <li><a href="/glossary.html">Glossary</a></li> <li><a href="/feedback.html">Feedback</a></li> <li><a href="/awards.html">Awards</a></li> <li><a href="/credits.html">Credits</a></li> <li><a href="http://blogs.dnalc.org/dnaftb/" style="background-image:none;">Blog</a></li> </ul> <p> Funded by <a href="http://macyfoundation.org">The Josiah Macy, Jr. Foundation</a><br /> © 2002 - 2011, <a href="http://www.dnalc.org/"> DNA Learning Center</a>, <a href="https://www.cshl.edu/">Cold Spring Harbor Laboratory</a>. All rights reserved. </p> </div>  </div> <div id="sidebar"> <div id="search" > <form method="get" action="/search"> <div class="fieldHolder1"> <input type="search" id="q" name="q" placeholder="Search" onclick="this.value=''" value="" /> <img style="background-color:#9C0;" src="/images/general/search_icon.jpg" alt="Search" onclick="document.forms[0].submit()" /> </div> </form> </div>  <div id="sidebar"> <ul class="menu-side" > <li class="section1"><a href="/1/index.html" title="Classical Genetics"><span class="displace">CLASSICAL GENETICS</span></a></li> <li class="section2" style="margin-bottom: 3px;"><a href="/15/index.html" title="Molecules of Genetics"><span class="displace">MOLECULES OF GENETICS</span></a></li>  </ul> <ul class="sections-side sections-side3a" style="padding-top: 56px;" > <li ><a href="/29/"><img src="/images/thumbnails/29-thumb-sm.png" alt="29." />DNA is packaged in a chromosome.</a></li> <li ><a href="/30/"><img src="/images/thumbnails/30-thumb-sm.png" alt="30." />Higher cells incorporate an ancient chromosome.</a></li> <li ><a href="/31/"><img src="/images/thumbnails/31-thumb-sm.png" alt="31." />Some DNA does not encode protein.</a></li> <li ><a href="/32/"><img src="/images/thumbnails/32-thumb-sm.png" alt="32." />Some DNA can jump.</a></li> <li ><a href="/33/"><img src="/images/thumbnails/33-thumb-sm.png" alt="33." />Genes can be turned on and off.</a></li> <li ><a href="/34/"><img src="/images/thumbnails/34-thumb-sm.png" alt="34." />Genes can be moved between species.</a></li> <li ><a href="/35/"><img src="/images/thumbnails/35-thumb-sm.png" alt="35." />DNA responds to signals from outside the cell.</a></li> <li ><a href="/36/"><img src="/images/thumbnails/36-thumb-sm.png" alt="36." />Different genes are active in different kinds of cells.</a></li> <li ><a class="concept-highlight" href="/37/"><img src="/images/thumbnails/37-thumb-sm.png" alt="37." />Master genes control basic body plans.</a></li> <li ><a href="/38/"><img src="/images/thumbnails/38-thumb-sm.png" alt="38." />Development balances cell growth and death.</a></li> <li ><a href="/39/"><img src="/images/thumbnails/39-thumb-sm.png" alt="39." />A genome is an entire set of genes.</a></li> <li ><a href="/40/"><img src="/images/thumbnails/40-thumb-sm.png" alt="40." />Living things share common genes.</a></li> <li style="border-bottom: 1px solid #669;"><a href="/41/"><img src="/images/thumbnails/41-thumb-sm.png" alt="41." />DNA is only the beginning for understanding the human genome.</a></li> </ul> </div>  </div>  <br class="clearfloat" /> </div>  <script type="text/javascript"> Event.observe(window, 'load', function() { var uri = '/37/index.html'; uri = uri.replace(/-\d/,''); $('nav').down().descendants().each(function(s) { if (s.nodeName == 'A') { if (s.href.match(uri)) { s.addClassName('current'); throw $break; } } }); }); </script> <script type="text/javascript"> var _gaq = _gaq || []; _gaq.push(['_setAccount', 'UA-1818773-10']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = 'https://www.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); </script>  <script async src="https://www.googletagmanager.com/gtag/js?id=G-K6EHFCRJBP"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'G-K6EHFCRJBP'); </script> </body> </html>