The Drosophila brain contains tens of thousands of distinct cell types. Thousands of different transgenic lines reproducibly target specific neuron subsets, yet most still express in several cell types. Furthermore, most lines were developed without a priori knowledge of where the transgenes would be expressed. To aid in the development of cell type–specific tools for neuronal identification and manipulation, we developed an iterative assay for transposase-accessible chromatin (ATAC) approach. Open chromatin regions (OCRs) enriched in neurons, compared to whole bodies, drove transgene expression preferentially in subsets of neurons. A second round of ATAC-seq from these specific neuron subsets revealed additional enriched OCR2s that further restricted transgene expression within the chosen neuron subset. This approach allows for continued refinement of transgene expression, and we used it to identify neurons relevant for sleep behavior. Furthermore, this approach is widely applicable to other cell types and to other organisms.

中文翻译：

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通过测序对转座酶可及的染色质进行迭代测定，以分离功能相关的神经元亚型

果蝇大脑包含数以万计的不同细胞类型。数以千计的不同转基因系可重复地靶向特定的神经元亚群，但大多数仍然在多种细胞类型中表达。此外，大多数品系是在事先不知道转基因将在何处表达的情况下开发的。为了帮助开发用于神经元识别和操作的细胞类型特异性工具，我们开发了一种转座酶可及染色质（ATAC）方法的迭代测定。与全身相比，开放染色质区域（OCR）在神经元中富集，优先在神经元亚群中驱动转基因表达。来自这些特定神经元子集的第二轮 ATAC-seq 揭示了额外富集的 OCR2，进一步限制了所选神经元子集中的转基因表达。这种方法允许持续细化转基因表达，我们用它来识别与睡眠行为相关的神经元。此外，这种方法广泛适用于其他细胞类型和其他生物体。