<p>This conserved pathway involves feedback regulation of transcription by CLE dodecapeptides. The organizing center (OC) in SAM stem cell niche and the quiescent center (QC) in RAM stem cell niche are indicated in red in the diagram (Adapted from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0089241#pone.0089241-Murphy1" target="_blank">[3]</a>).</p