轉(zhuǎn)錄（一個細胞的DNA模板的一個序列的互補性RNA版本的生成）正在成為一個比僅僅在幾年前所認為的要更為復雜的過程,。例如,，“RNA聚合酶暫停”是普遍存在的，從而為各種不同調(diào)控過程提供一個焦點,，而且很多轉(zhuǎn)錄副本注定要迅速退化,。為了研究這些現(xiàn)象，Stirling Churchman 和 Jonathan Weissman建立了一種被稱為“native elongating transcript sequencing (NET-seq)”的方法,，該方法能夠以單核苷酸分辨率對轉(zhuǎn)錄進行量化,。NET-seq基于對與從活細胞直接獲取的“RNA聚合酶-II”相關(guān)的新生副本進行測序。他們利用這一新方法對釀酒酵母的聚合酶暫停和回撤以及轉(zhuǎn)錄的方向性進行了研究,。（生物谷Bioon.com）
生物谷推薦原文出處：
Nature doi:10.1038/nature09652
Nascent transcript sequencing visualizes transcription at nucleotide resolution
L. Stirling Churchman& Jonathan S. Weissman
Recent studies of transcription have revealed a level of complexity not previously appreciated even a few years ago, both in the intricate use of post-initiation control and the mass production of rapidly degraded transcripts. Dissection of these pathways requires strategies for precisely following transcripts as they are being produced. Here we present an approach (native elongating transcript sequencing, NET-seq), based on deep sequencing of 3′ ends of nascent transcripts associated with RNA polymerase, to monitor transcription at nucleotide resolution. Application of NET-seq in Saccharomyces cerevisiae reveals that although promoters are generally capable of divergent transcription, the Rpd3S deacetylation complex enforces strong directionality to most promoters by suppressing antisense transcript initiation. Our studies also reveal pervasive polymerase pausing and backtracking throughout the body of transcripts. Average pause density shows prominent peaks at each of the first four nucleosomes, with the peak location occurring in good agreement with in vitro biophysical measurements. Thus, nucleosome-induced pausing represents a major barrier to transcriptional elongation in vivo.
