Abstract：
Previous work showed that the simple eukaryote Saccharomyces cerevisiae contains a group of RNAs with the general structural properties predicted for small nuclear RNAs (snRNAs), including possession of the characteristic trimethylguanosine 5\'-terminal cap. It was also demonstrated that, unlike their metazoan counterparts, the yeast snRNAs are present in low abundance (200-500 molecules per haploid cell). We have now used antibody directed against the 5\' cap to investigate the total set size of snRNAs in this organism. We present evidence that the number of distinct yeast snRNAs is on the order of several dozen, that the length of the capped RNAs can exceed 1000 nucleotides, and that the relative abundance of a subset of these RNAs is 1/5th to 1/20th that of the class of snRNAs described previously. These findings suggest that the six highly abundant species of snRNAs (U1-U6) typically reported in metazoans may represent a serious underestimation of the total diversity of snRNAs in eukaryotes.
摘要：
先前的工作表明，简单的真核酿酒酵母包含一组具有小核RNA（snRNA）预测的一般结构特性的RNA，包括拥有特征性的三甲基鸟苷5'端帽。还表明，与后生动物不同，酵母snRNA以低丰度(每个单倍体细胞200-500个分子)存在。我们现在已经使用针对5'帽的抗体来研究该生物体中snRNA的总集合大小。我们提供的证据表明，不同的酵母snRNAs的数量大约是几十个，加帽的RNA的长度可以超过1000个核苷酸，并且这些RNA的子集的相对丰度是先前描述的snRNA类别的1/5至1/20。这些发现表明，通常在后生动物中报告的六种高度丰富的snRNA（U1-U6）可能严重低估了真核生物中snRNA的总多样性。
