Regulation of hemimetaboly and holometaboly. KonopovaBarbora SmykalVlastimil JindraMarek 2011 <p><i>Pyrrhocoris</i> (left) and <i>Tribolium</i> (right) cartoons signify the main innovations – postponement of wing development and the resting pupal stage in holometabolans. The absence of JH-dependent <i>Kr-h1</i> expression in pupae and final instar hemimetabolous larvae (gray shaded areas) is prerequisite to adult development in both types of metamorphosis, supporting the view that these final juvenile stages of both insects types may be homologous <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0028728#pone.0028728-Sehnal1" target="_blank">[1]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0028728#pone.0028728-Hinton1" target="_blank">[35]</a>. The orange shaded area marks a period of low <i>Kr-h1</i> activity in the absence of JH, which is necessary to permit partial metamorphosis during the pupal molt, specified by the newly acquired function of <i>BR-C</i> in holometabolans. Gene expression profiles for <i>Pyrrhocoris</i> and <i>Tribolium</i> are from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0028728#pone-0028728-g001" target="_blank">Figure 1B</a> and from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0028728#pone.0028728-Minakuchi2" target="_blank">[17]</a>, respectively. JH and ecdysteroid titers are from <i>Blattella germanica </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0028728#pone.0028728-Belles1" target="_blank">[34]</a> (left) and <i>Manduca sexta </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0028728#pone.0028728-Riddiford1" target="_blank">[5]</a> (right).</p>