Specification of sensory primordia by the synergistic action of SOX2 and its partner factor

感觉组织，如嗅觉上皮，内耳和晶状体，从头外胚层经过渐进的规范步骤发育。由于阶段/基板特异性增强子的顺序激活，无论发育阶段如何，转录因子基因Sox2都在感觉原基中一致表达。NOP1增强子在鼻腔和耳部基板中特别活跃。NOP1增强子的一个重要激活元件被证明受Sox2和Sall4以及Sox9和Sall4的协同作用调节（但不受Sox11和Sall4的影响）。头后外胚层Sox活性的抑制使NOP1增强子失活。这些数据表明，Sox-Sall4协同作用对于鼻腔和耳部基板中的sox2调控至关重要。

Sensory tissues, e.g. olfactory epithelium, inner ear and lens, develop from cephalic ectoderm through progressive specification steps. The transcription factor gene Sox2 is consistently expressed in the sensory primordia regardless of developmental stages, owing to the sequential activation of stage-/placode-specific enhancers. The NOP1 enhancer is specifically active in the nasal and otic placodes. An essential activating element of NOP1 enhancer was shown to be regulated by the synergistic action of Sox2 and Sall4, as well as Sox9 and Sall4 (but not Sox11 and Sall4). Inhibition of Sox activity in the posterior cephalic ectoderm inactivated the NOP1 enhancer. These data indicate that Sox-Sall4 synergism is essential for Sox2regulation in the nasal and otic placodes.