美国宾夕法尼亚大学Wu, Hao课题组利用联合单细胞谱分析了5-甲基胞嘧啶(5mC)和5-羟甲基胞嘧啶(5hmC)，揭示了它们不同的基因调控作用。2023年8月28日出版的《自然—生物技术》杂志发表了

他们提出了联合单核(羟基)甲基胞嘧啶测序(Joint-snhmC-seq)，这是一种可扩展的定量方法，通过利用APOBEC3A对5mC和化学保护的5hmC的差异脱氨酶活性，同时分析单细胞中的5hmC和真5mC。小鼠大脑单核的联合Joint-snhmC-seq分析揭示了5hmC和真5mC在单细胞分辨率上前所未有的表观遗传异质性。

他们发现5hmC或真5mC的细胞类型特异性谱改善了多模态单细胞数据整合，能够准确识别神经元亚型，并揭示ten-eleven易位(TET)酶对细胞类型特异性基因的环境特异性调节作用。

研究人员表示，TETDNA双加氧酶对5mC进行氧化修饰，生成5hmC，这是氧化5mC最丰富的形式。现有的单细胞亚硫酸盐测序方法无法分辨5mC和5hmC，使得TET和5hmC的细胞类型特异性调控机制在很大程度上未知。

附：英文原文

Title: Joint single-cell profiling resolves 5mC and 5hmC and reveals their distinct gene regulatory effects

Author: Fabyanic, Emily B., Hu, Peng, Qiu, Qi, Berros, Kiara N., Connolly, Daniel R., Wang, Tong, Flournoy, Jennifer, Zhou, Zhaolan, Kohli, Rahul M., Wu, Hao

Issue&Volume: 2023-08-28

Abstract: Oxidative modification of 5-methylcytosine (5mC) by ten-eleven translocation (TET) DNA dioxygenases generates 5-hydroxymethylcytosine (5hmC), the most abundant form of oxidized 5mC. Existing single-cell bisulfite sequencing methods cannot resolve 5mC and 5hmC, leaving the cell-type-specific regulatory mechanisms of TET and 5hmC largely unknown. Here, we present joint single-nucleus (hydroxy)methylcytosine sequencing (Joint-snhmC-seq), a scalable and quantitative approach that simultaneously profiles 5hmC and true 5mC in single cells by harnessing differential deaminase activity of APOBEC3A toward 5mC and chemically protected 5hmC. Joint-snhmC-seq profiling of single nuclei from mouse brains reveals an unprecedented level of epigenetic heterogeneity of both 5hmC and true 5mC at single-cell resolution. We show that cell-type-specific profiles of 5hmC or true 5mC improve multimodal single-cell data integration, enable accurate identification of neuronal subtypes and uncover context-specific regulatory effects on cell-type-specific genes by TET enzymes.

DOI: 10.1038/s41587-023-01909-2

Source: https://www.nature.com/articles/s41587-023-01909-2