Mus musculus strain:C57BL/6J Raw sequence reads. Mus musculus strain:C57BL/6J

How gene expression temporally unfolds and is regulated to shape post-differentiation development of neuronal identity is poorly understood. Here, RNA-sequencing of flow sorted serotonin (5-HT) neurons uncovers multiple discretegene expression trajectories during 5-HT neuron maturation. Integration of ChIP-seq and RNA-seq datasets shows that transcription factor, Pet-1/FEV, regulatestrajectories of diverse targets including a transcription factor network and pan-neuronal and neuron-type identity features. The profound disruption ofexpression patterns in Pet-1-/- 5-HT neurons permanently stalled maturation oftheir active and passive membrane characteristics. Collapse of specifictrajectories blocked acquisition of glutamatergic and G-protein coupled receptor-signaling pathways required for mature afferent responses of 5-HT neurons.Moreover, continuous transcriptional activity was required to shape trajectories ofkey identity features defining mature 5-HT neurons. Our findings identify atranscriptional program that promotes maturation of serotonergic efferent andafferent connectivity and provides a framework for understanding how immatureserotonergic activity may contribute to psychiatric disorders.人们对基因表达的时序动态调控机制，以及其如何塑造神经元身份的分化后发育过程，仍缺乏充分认知。本研究通过对流式分选的5-羟色胺（serotonin，5-HT）神经元开展RNA测序（RNA-seq），揭示了5-HT神经元成熟过程中存在多条离散的基因表达轨迹。整合染色质免疫共沉淀测序（ChIP-seq）与RNA-seq数据集的分析结果显示，转录因子Pet-1/FEV可调控多种靶标的表达轨迹，涵盖转录因子网络、泛神经元特征以及神经元类型特异性身份特征。Pet-1基因敲除（Pet-1-/-）的5-HT神经元中，基因表达模式出现严重紊乱，使其主动与被动膜特性的成熟过程永久停滞。特定基因表达轨迹的崩溃，会阻碍5-HT神经元获得成熟传入应答所需的谷氨酸能信号通路与G蛋白偶联受体信号通路。此外，维持持续的转录活性，对于塑造定义成熟5-HT神经元的关键身份特征的表达轨迹至关重要。本研究鉴定出一套可促进5-羟色胺能神经元传出与传入连接成熟的转录程序，并为解析未成熟5-羟色胺能活性如何参与精神疾病发病机制提供了理论框架。