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，通过循序渐进的指定步骤从头外胚层发育而来。转录因子基因Sox2在不同发育阶段的感觉原基中持续表达，这是由于阶段/胎盘特异性增强子的顺序激活。NOP1增强子在鼻部和耳部安慰剂中特别有效。NOP1增强子的一个重要激活元件受Sox2和Sall4以及Sox9和Sall4(而不是Sox11和Sall4)的协同作用的调节。抑制头后外胚层的SOX活性使NOP1增强子失活。这些数据表明，Sox-Sall4的协同作用对于鼻安慰剂和耳安慰剂中的Sox2调节是必不可少的。

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.