Terminal selectors are transcription factors that control the morphological, physiological, and molecular features that characterize distinct cell types. Here, we show that, in the sea anemone Nematostella vectensis, NvPOU4 is expressed in post-mitotic cells that give rise to a diverse set of neural cell types, including cnidocytes and NvElav1-expressing neurons. Morphological analyses of NvPOU4 mutants crossed to transgenic reporter lines show that the loss of NvPOU4 does not affect the initial specification of neural cells. Transcriptomes derived from the mutants and from different neural cell populations reveal that NvPOU4 is required for the execution of the terminal differentiation program of these neural cells. These findings suggest that POU4 genes have ancient functions as terminal selectors for morphologically and functionally disparate types of neurons and they provide experimental support for the relevance of terminal selectors for understanding the evolution of cell types.

末端选择子是转录因子，可控制表征不同细胞类型的形态，生理和分子特征。在这里，我们表明，在海葵线虫Nematostella vectensis中，NvPOU4在有丝分裂后的细胞中表达，产生了多种神经细胞类型，包括小细胞和表达NvElav1的神经元。对与转基因报告基因系杂交的NvPOU4突变体的形态学分析表明，NvPOU4的丢失不影响神经细胞的初始规格。来自突变体和来自不同神经细胞群体的转录组揭示了NvPOU4这些神经细胞的终末分化程序的执行是必需的。这些发现表明，POU4基因具有古老的功能，可以作为形态和功能上不同的神经元的末端选择器，并且它们为末端选择器对于了解细胞类型进化的相关性提供了实验支持。