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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>The RNA message is sometimes edited :: DNA from the Beginning</title> <meta name="description" content="RNA splicing removes non-coding introns and splices together exons." /> <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 24</span> The RNA message is sometimes edited.</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/24/concept24.jpg" class="concept-image" alt="The RNA message is sometimes edited." /> <p>Dogma and logic dictated that the mRNA code is a faithful representation of the DNA from which it is transcribed. This exact correspondence between mRNA sequence and DNA sequence was generally upheld in experiments with bacterial cells (prokaryotes).However, inconsistencies surfaced as recombinant-DNA techniques allowed researchers to explore the genes of higher cells (eukaryotes). Then, it was found that mRNA transcripts appeared to be shorter than their corresponding genes. This difference became obvious in electron micrographs of mRNA bound to its complementary DNA template — where regions of DNA without corresponding mRNA form loops. </p> <p>In fact, the protein coding information in genes is interrupted by non-coding sequences called introns, which results in "split genes." The entire DNA code is faithfully transcribed into a temporary form of RNA (pre-mRNA), but this is edited in the nucleus to yield a mature mRNA. The process of RNA splicing involves removing non-coding regions, introns, and splicing together adjacent coding regions, exons. </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" style="margin-bottom: 3px;"><a href="/1/index.html" title="Classical Genetics"><span class="displace">CLASSICAL GENETICS</span></a></li> </ul> <ul class="sections-side sections-side2a" style="padding-top: 56px;"> <li ><a href="/15/"><img src="/images/thumbnails/15-thumb-sm.png" alt="15." />DNA and proteins are key molecules of the cell nucleus.</a></li> <li ><a href="/16/"><img src="/images/thumbnails/16-thumb-sm.png" alt="16." />One gene makes one protein.</a></li> <li ><a href="/17/"><img src="/images/thumbnails/17-thumb-sm.png" alt="17." />A gene is made of DNA.</a></li> <li ><a href="/18/"><img src="/images/thumbnails/18-thumb-sm.png" alt="18." />Bacteria and viruses have DNA too.</a></li> <li ><a href="/19/"><img src="/images/thumbnails/19-thumb-sm.png" alt="19." />The DNA molecule is shaped like a twisted ladder.</a></li> <li ><a href="/20/"><img src="/images/thumbnails/20-thumb-sm.png" alt="20." />A half DNA ladder is a template for copying the whole.</a></li> <li ><a href="/21/"><img src="/images/thumbnails/21-thumb-sm.png" alt="21." />RNA is an intermediary between DNA and protein.</a></li> <li ><a href="/22/"><img src="/images/thumbnails/22-thumb-sm.png" alt="22." />DNA words are three letters long.</a></li> <li ><a href="/23/"><img src="/images/thumbnails/23-thumb-sm.png" alt="23." />A gene is a discrete sequence of DNA nucleotides.</a></li> <li ><a class="concept-highlight" href="/24/"><img src="/images/thumbnails/24-thumb-sm.png" alt="24." />The RNA message is sometimes edited.</a></li> <li ><a href="/25/"><img src="/images/thumbnails/25-thumb-sm.png" alt="25." />Some viruses store genetic information in RNA.</a></li> <li ><a href="/26/"><img src="/images/thumbnails/26-thumb-sm.png" alt="26." />RNA was the first genetic molecule.</a></li> <li ><a href="/27/"><img src="/images/thumbnails/27-thumb-sm.png" alt="27." />Mutations are changes in genetic information.</a></li> <li style="border-bottom: 1px solid #669;"><a href="/28/"><img src="/images/thumbnails/28-thumb-sm.png" alt="28." />Some types of mutations are automatically repaired.</a></li> </ul> <ul class="menu-side"> <li class="section3"><a href="/29/index.html" title="Genetic Organization and Control"><span class="displace">GENETIC ORGANIZATION AND CONTROL</span></a></li> </ul> </div> </div>  <br class="clearfloat" /> </div>  <script type="text/javascript"> Event.observe(window, 'load', function() { var uri = '/24/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>