Subcellular Single Cell Sequencing: mRNA Diversity of Individual Glutamatergic and GABAergic Hippocampal Neurons and their Dendrites.

Neurons transport a variety of mRNAs to their dendritic and axonal compartments where they are locally translated. These processes are essential for the functional specialization of these cellular structures. To explore both the intercellular variability and intracellular dynamics of neuronal compartments we characterized the somatic and dendritic transcriptome of single neurons. We used Laser Capture Microdissection to isolate the dendrites and soma of individual neurons from primary hippocampal cultures, followed by scRNA-seq to profile the mRNA content of these compartments. In total, we sequence 276 dendrites and their respective somata, 227 somata without the dendrites, and 16 negative controls (LCM cuts of areas without cellular content). We observed less cell-type specific differences in the dendritic transcriptome than in the somatic transcriptome. However, the dendritic localization of a subset of mRNAs does vary in a cell-type specific manner. Furthermore, we observed that the relation between somatic and dendritic abundance varies according to gene and is strongly influenced by cellular function. This study provides a framework for the regulation of the dendritic transcriptome within and across individual neurons.神经元可将多种mRNA转运至树突与轴突区室，并在该区域完成局部翻译。这一过程对这些细胞结构的功能特化具有关键意义。为探究神经元区室的细胞间异质性与细胞内动态变化，我们对单个神经元的胞体与树突转录组开展了表征分析。我们采用激光捕获显微切割（Laser Capture Microdissection, LCM）技术，从原代海马神经元培养物中分离出单个神经元的树突与胞体，随后通过单细胞RNA测序（scRNA-seq）对上述区室的mRNA含量进行解析。本研究共完成276组树突及其对应胞体、227组无树突的胞体，以及16份阴性对照（无细胞区域的激光捕获显微切割样本）的测序。我们观察到，树突转录组的细胞类型特异性差异弱于胞体转录组。然而，部分mRNA的树突定位仍呈现细胞类型特异性的变化。此外，我们发现胞体与树突的mRNA丰度相关性因基因而异，且显著受细胞功能的影响。本研究为单个神经元内部以及不同神经元之间的树突转录组调控提供了研究框架。