<i>Hes7</i> is required for regular sacral segmentation in <i>Lfng<sup>−/−</sup></i> embryos, but need not oscillate. StauberMichael SachidanandanChetana MorgensternChristina Ish-HorowiczDavid 2009 <p>(A, B) Segmentation in <i>Hes7<sup>−/−</sup></i> mice is irregular all along the axis (including the sacrum) as visualised by <i>Uncx4.1</i> staining of embryos (A) and foetal skeleton preparation (B; top, lateral view; bottom, ventral view; scale bars are 5 mm). For annotation, see legend to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0007996#pone-0007996-g003" target="_blank">Figures 3</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0007996#pone-0007996-g002" target="_blank">2</a>. (C) <i>In situ</i> hybridisation with a <i>Hes7</i> intron probe to visualise active transcription (left) shows a clearly dynamic pattern in <i>Lfng<sup>+/−</sup></i> PSMs (top) but a strong background throughout <i>Lfng<sup>−/−</sup></i> PSMs (bottom). A <i>Hes7</i> cDNA probe (C right) visualises dynamic transcript distribution in <i>Lfng<sup>+/−</sup></i> PSMs (top) but mainly ubiquitous staining in <i>Lfng<sup>−/−</sup></i> PSMs (bottom; embryos showing dynamic expression domain most clearly were selected).</p>