【资讯】重编程piRNA通路可实现线虫中多基因和跨代的基因沉默-基因在线-Gene Online

沙特阿拉伯阿卜杜拉国王科技大学Christian Frøkjær-Jensen研究组发现，重编程piRNA通路可实现线虫中多基因和跨代的基因沉默。相关论文于2022年2月3日在线发表于国际学术期刊《自然—方法学》。

研究人员发现，由染色体外转基因表达的短的合成向导Piwi-interacting RNA（piRNA）（21个核苷酸的sg-piRNA）可以类似地重新编程内源性piRNA途径，在线虫雌雄同体的生殖系、精子和胚胎中进行基因特异性沉默。piRNA介导的干扰（'piRNAi'）比RNAi更有效，而且可以复用，生长素介导的piRNA特异性Argonaute PRG-1的降解能够实现有条件的基因沉默。靶标特异性沉默的结果是信使RNA水平下降，二级小干扰RNA的扩增以及抑制性的染色质修饰。短的（300个碱基对）piRNAi转基因从排列的寡核苷酸池中扩增出来，也能诱导沉默，有可能使piRNAi高度可扩展。

结果表明，piRNAi可以诱导两个内源性基因（him-5和him-8）的跨代表观遗传学沉默。在靶标特异性sg-piRNA消失后，沉默会遗传四到六代，而耗尽PRG-1则会导致基本永久性的表观遗传沉默。

据悉，单向导RNA可以将外源CRISPR-Cas蛋白靶向到独特的DNA位置，使遗传工具高效、特异且可扩展。

附：英文原文

Title: Reprogramming the piRNA pathway for multiplexed and transgenerational gene silencing in C. elegans

Author: Priyadarshini, Monika, Ni, Julie Zhouli, Vargas-Velazquez, Amhed M., Gu, Sam Guoping, Frkjr-Jensen, Christian

Issue&Volume: 2022-02-03

Abstract: Single-guide RNAs can target exogenous CRISPR–Cas proteins to unique DNA locations, enabling genetic tools that are efficient, specific and scalable. Here we show that short synthetic guide Piwi-interacting RNAs (piRNAs) (21-nucleotide sg-piRNAs) expressed from extrachromosomal transgenes can, analogously, reprogram the endogenous piRNA pathway for gene-specific silencing in the hermaphrodite germline, sperm and embryos of Caenorhabditis elegans. piRNA-mediated interference (‘piRNAi’) is more efficient than RNAi and can be multiplexed, and auxin-mediated degradation of the piRNA-specific Argonaute PRG-1 allows conditional gene silencing. Target-specific silencing results in decreased messenger RNA levels, amplification of secondary small interfering RNAs and repressive chromatin modifications. Short (300base pairs) piRNAi transgenes amplified from arrayed oligonucleotide pools also induce silencing, potentially making piRNAi highly scalable. We show that piRNAi can induce transgenerational epigenetic silencing of two endogenous genes (him-5 and him-8). Silencing is inherited for four to six generations after target-specific sg-piRNAs are lost, whereas depleting PRG-1 leads to essentially permanent epigenetic silencing.

DOI: 10.1038/s41592-021-01369-z

编辑：小柯机器人