Single-cell CAS-seq reveals a class of short PIWI-interacting RNAs in human oocytes

作者：Qiyuan Yang, Ronghong Li, Qifeng Lyu, Li Hou, Zhen Liu, Qiang Sun, Miao Liu, Huijuan Shi, Beiying Xu, Mingru Yin, Zhiguang Yan, Ying Huang, Mo‐Fang Liu, Yi‐Ping Li, Ligang Wu · 发表于：Nature Communications · 年份：2019 · DOI：10.1038/s41467-019-11312-8 · 被引用次数：112 · 研究领域：Chromosomal and Genetic Variations、MicroRNA in disease regulation、RNA modifications and cancer

Small RNAs have important functions. However, small RNAs in primate oocytes remain unexplored. Herein, we develop CAS-seq, a single-cell small RNA sequencing method, and profile the small RNAs in human oocytes and embryos. We discover a class of ~20-nt small RNAs that are predominantly expressed in human and monkey oocytes, but not in mouse oocytes. They are specifically associated with HIWI3 (PIWIL3), whereas significantly shorter than the commonly known PIWI-interacting RNAs (piRNAs), designated as oocyte short piRNAs (os-piRNAs). Notably, the os-piRNAs in human oocytes lack 2'-O-methylation at the 3' end, a hallmark of the classic piRNAs. In addition, the os-piRNAs have a strong 1U/10 A bias and are enriched on the antisense strands of recently evolved transposable elements (TEs), indicating the potential function of silencing TEs by cleavage. Therefore, our study has identified an oocyte-specific piRNA family with distinct features and provides valuable resources for studying small RNAs in primate oocytes.