Fig. 11
From: Ancestral role of Pax2/5/8 in molluscan brain and multimodal sensory system development
Pax2/5/8 has been independently recruited in brain regionalization in various bilaterian subgroups. Expression of Otx, Pax2/5/8, and anterior Hox genes during brain formation in a lophotrochozoan (cephalopod), an ecdysozoan (Drosophila melanogaster), and a deuterostome (Mus musculus). Anterior-most brain regions face up and posterior-most brain regions face down. The cephalopod vertical lobe does not express Otx, Pax2/5/8, or Hox genes. The superior frontal, subpedunculate, and median basal lobes express Otx in Sepia officinalis [31] and the anterior basal and interbasal lobes express Pax2/5/8 in Idiosepius notoides (present study). The posterior subesophageal mass and the posterior perikaryal layer of the middle subesophageal mass express Pax2/5/8 in I. notoides (present study). Anterior Hox genes are expressed in the palliovisceral and pedal ganglia/ subesophageal mass of other cephalopods [32]. Sketch modified after [14]