Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720, USA.
Neuroscience. 2023 Jan 1;508:153-173. doi: 10.1016/j.neuroscience.2022.07.013. Epub 2022 Jul 21.
The development and connectivity of retinal ganglion cells (RGCs), the retina's sole output neurons, are patterned by activity-independent transcriptional programs and activity-dependent remodeling. To inventory the molecular correlates of these influences, we applied high-throughput single-cell RNA sequencing (scRNA-seq) to mouse RGCs at six embryonic and postnatal ages. We identified temporally regulated modules of genes that correlate with, and likely regulate, multiple phases of RGC development, ranging from differentiation and axon guidance to synaptic recognition and refinement. Some of these genes are expressed broadly while others, including key transcription factors and recognition molecules, are selectively expressed by one or a few of the 45 transcriptomically distinct types defined previously in adult mice. Next, we used these results as a foundation to analyze the transcriptomes of RGCs in mice lacking visual experience due to dark rearing from birth or to mutations that ablate either bipolar or photoreceptor cells. 98.5% of visually deprived (VD) RGCs could be unequivocally assigned to a single RGC type based on their transcriptional profiles, demonstrating that visual activity is dispensable for acquisition and maintenance of RGC type identity. However, visual deprivation significantly reduced the transcriptomic distinctions among RGC types, implying that activity is required for complete RGC maturation or maintenance. Consistent with this notion, transcriptomic alternations in VD RGCs significantly overlapped with gene modules found in developing RGCs. Our results provide a resource for mechanistic analyses of RGC differentiation and maturation, and for investigating the role of activity in these processes.
视网膜神经节细胞（RGC）的发育和连接，是视网膜唯一的输出神经元，受到活动无关的转录程序和活动依赖的重塑的影响。为了确定这些影响的分子相关性，我们应用高通量单细胞 RNA 测序（scRNA-seq）对六个胚胎和新生期的小鼠 RGC 进行了研究。我们确定了与 RGC 发育的多个阶段相关的、可能具有调节作用的基因模块，这些阶段包括分化、轴突导向、突触识别和细化。其中一些基因广泛表达，而另一些基因，包括关键的转录因子和识别分子，仅由成年小鼠中先前定义的 45 种转录不同类型中的一种或几种表达。接下来，我们利用这些结果作为基础，分析了由于出生后即进行暗室饲养而缺乏视觉经验的小鼠或由于缺失双极细胞或光感受器细胞而导致视觉缺失的 RGC 的转录组。98.5%的视觉剥夺（VD）RGC 可以根据其转录谱明确地分配到单个 RGC 类型，这表明视觉活动对于获得和维持 RGC 类型身份是可有可无的。然而，视觉剥夺显著降低了 RGC 类型之间的转录组差异，这意味着活动对于 RGC 的完全成熟或维持是必需的。与这一观点一致，VD RGC 中的转录组变化与在发育中的 RGC 中发现的基因模块显著重叠。我们的研究结果为 RGC 分化和成熟的机制分析提供了资源，并为研究活动在这些过程中的作用提供了线索。
