tailieunhanh - Báo cáo y học: "Genomewide characterization of non-polyadenylated RNA"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Genomewide characterization of non-polyadenylated RNAs. | Yang et al. Genome Biology 2011 12 R16 http 2011 12 2 R16 Genome Biology RESEARCH Open Access Genomewide characterization of non-polyadenylated RNAs 1 1 1 Li Yang1 Michael O Duff1 Brenton R Graveley1 Gordon G Carmichael1 Ling-Ling Chen1 2 Abstract Background RNAs can be physically classified into poly A or poly A - transcripts according to the presence or absence of a poly A tail at their 3 ends. Current deep sequencing approaches largely depend on the enrichment of transcripts with a poly A tail and therefore offer little insight into the nature and expression of transcripts that lack poly A tails. Results We have used deep sequencing to explore the repertoire of both poly A and poly A - RNAs from HeLa cells and H9 human embryonic stem cells hESCs . Using stringent criteria we found that while the majority of transcripts are poly A a significant portion of transcripts are either poly A - or bimorphic being found in both the poly A and poly A - populations. Further analyses revealed that many mRNAs may not contain classical long poly A tails and such messages are overrepresented in specific functional categories. In addition we surprisingly found that a few excised introns accumulate in cells and thus constitute a new class of non-polyadenylated long non-coding RNAs. Finally we have identified a specific subset of poly A - histone mRNAs including two histone H1 variants that are expressed in undifferentiated hESCs and are rapidly diminished upon differentiation further these same histone genes are induced upon reprogramming of fibroblasts to induced pluripotent stem cells. Conclusions We offer a rich source of data that allows a deeper exploration of the poly A - landscape of the eukaryotic transcriptome. The approach we present here also applies to the analysis of the poly A - transcriptomes of other organisms. Background Nascent pre-mRNA transcripts undergo multiple co-transcriptional post-transcriptional processing and modification .