Popsuj Sydney, Stolfi Alberto
School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States.
Front Neurosci. 2021 Dec 17;15:784649. doi: 10.3389/fnins.2021.784649. eCollection 2021.
Conserved transcription factors termed "terminal selectors" regulate neuronal sub-type specification and differentiation through combinatorial transcriptional regulation of terminal differentiation genes. The unique combinations of terminal differentiation gene products in turn contribute to the functional identities of each neuron. One well-characterized terminal selector is COE (Collier/Olf/Ebf), which has been shown to activate cholinergic gene batteries in motor neurons. However, its functions in other metazoans, particularly chordates, is less clear. Here we show that the sole COE ortholog in the non-vertebrate chordate , Ebf, controls the expression of the cholinergic locus in a single dorsal interneuron of the larval Motor Ganglion, which is presumed to be homologous to the vertebrate spinal cord. We propose that, while the function of Ebf as a regulator of cholinergic neuron identity conserved across bilaterians, its exact role may have diverged in different cholinergic neuron subtypes (e.g., interneurons vs. motor neurons) in chordate-specific motor circuits.
被称为“终末选择因子”的保守转录因子通过对终末分化基因的组合转录调控来调节神经元亚型的特化和分化。终末分化基因产物的独特组合反过来又有助于每个神经元的功能特性。一个得到充分表征的终末选择因子是COE（Collier/Olf/Ebf），它已被证明能激活运动神经元中的胆碱能基因组合。然而，它在其他后生动物，特别是脊索动物中的功能尚不清楚。在这里，我们表明，非脊椎动物脊索动物中的唯一COE直系同源物Ebf，控制着幼虫运动神经节单个背侧中间神经元中胆碱能基因座的表达，该神经节被认为与脊椎动物脊髓同源。我们提出，虽然Ebf作为胆碱能神经元身份调节因子的功能在两侧对称动物中是保守的，但其在脊索动物特异性运动回路中不同胆碱能神经元亚型（如中间神经元与运动神经元）中的具体作用可能已经发生了分化。
