A GENETIC, GENOMIC, AND COMPUTATIONAL RESOURCE FOR EXPLORING NEURAL CIRCUIT FUNCTION

The anatomy of many neural circuits is being characterized with increasing resolution, but their molecular properties remain mostly unknown. Here, we characterize gene expression patterns in distinct neural cell types of the Drosophila visual system using genetic lines to access individual cell types, the TAPIN-seq method to measure their transcriptomes, and a probabilistic method to interpret these measurements. We used these tools to build a resource of high-resolution transcriptomes for 100 driver lines covering 67 cell types. Combining these transcriptomes with recently reported connectomes helps characterize how information is transmitted and processed across a range of scales, from individual synapses to circuit pathways. We describe examples that include identifying neurotransmitters, including cases of co-release, generating functional hypotheses based on receptor expression, as well as identifying strong commonalities between different cell types. Overall design: 266 RNA-seq samples including 242 nuclear RNA-seq libraries prepared from specific cell types using INTACT/TAPIN, 8 samples dissected from the optic lobe, and 16 control libraries to characterize the INTACT/TAPIN protocols.

当前，诸多神经环路的解剖结构正以持续提升的分辨率被解析，但其分子特性仍大多未知。本研究借助可靶向单个神经元类型的遗传品系、用于检测转录组（transcriptome）的TAPIN-seq技术，以及用于解读此类数据的概率分析方法，对果蝇视觉系统中不同神经细胞类型的基因表达模式进行了系统表征。我们利用上述工具构建了一套高分辨率转录组资源库，包含覆盖67种细胞类型的100个驱动遗传品系。将该转录组资源与近期发表的连接组（connectome）相结合，有助于解析信息在从单个突触到环路通路的多尺度上的传递与处理机制。本研究展示了多个应用案例，包括识别神经递质（涵盖共同释放的情况）、基于受体表达构建功能假说，以及鉴定不同细胞类型间的显著共性。整体实验设计：本研究共包含266个RNA测序（RNA-seq）样本，其中242个为利用INTACT/TAPIN技术从特定细胞类型中制备的细胞核RNA-seq文库，8个为从视神经叶解剖获取的样本，另有16个对照文库用于表征INTACT/TAPIN实验流程。