LINE-1 retrotransposons are sequences capable of copying themselves to new genomic loci via an RNA intermediate. New studies implicate LINE-1 in a range of diseases, especially in the context of aging, but without an accurate understanding of where and when LINE-1 is expressed, a full accounting of its role in health and disease is not possible. We therefore developed a method – 5’ scL1seq – that makes use of a widely available library preparation method (10x Genomics 5’ single cell RNA-seq) to measure LINE-1 expression in tens of thousands of single cells. We recapitulated the known pattern of LINE-1 expression in tumors – present in cancer cells, absent from immune cells – and identified hitherto undescribed LINE-1 expression in human epithelial cells and mouse hippocampal neurons. In both cases, we saw a modest increase with age, supporting recent research connecting LINE-1 to age related diseases.

中文翻译：

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5' 单细胞 RNA-Seq 揭示的 LINE-1 逆转录转座子在癌细胞、上皮细胞和神经元细胞中的表达

LINE-1 反转录转座子是能够通过 RNA 中间体将自身复制到新基因组位点的序列。新的研究将 LINE-1 与一系列疾病联系起来，尤其是在衰老的背景下，但如果不能准确了解 LINE-1 的表达地点和时间，就不可能全面了解其在健康和疾病中的作用。因此，我们开发了一种方法 - 5' scL1seq - 利用广泛可用的文库制备方法（10x Genomics 5' 单细胞 RNA-seq）来测量数万个单细胞中的 LINE-1 表达。我们概括了肿瘤中已知的 LINE-1 表达模式——存在于癌细胞中，免疫细胞中不存在——并确定了迄今为止在人类上皮细胞和小鼠海马神经元中未描述的 LINE-1 表达。在这两种情况下，我们都看到随着年龄的增长而适度增加，