Genetics Programme, Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland, UK.
Nucleic Acids Res. 2010 May;38(9):3054-67. doi: 10.1093/nar/gkp1241. Epub 2010 Jan 16.
Small nucleolar RNAs (snoRNAs) and small Cajal body-specific RNAs (scaRNAs) are non-coding RNAs whose main function in eukaryotes is to guide the modification of nucleotides in ribosomal and spliceosomal small nuclear RNAs, respectively. Full-length sequences of Arabidopsis snoRNAs and scaRNAs have been obtained from cDNA libraries of capped and uncapped small RNAs using RNA from isolated nucleoli from Arabidopsis cell cultures. We have identified 31 novel snoRNA genes (9 box C/D and 22 box H/ACA) and 15 new variants of previously described snoRNAs. Three related capped snoRNAs with a distinct gene organization and structure were identified as orthologues of animal U13snoRNAs. In addition, eight of the novel genes had no complementarity to rRNAs or snRNAs and are therefore putative orphan snoRNAs potentially reflecting wider functions for these RNAs. The nucleolar localization of a number of the snoRNAs and the localization to nuclear bodies of two putative scaRNAs was confirmed by in situ hybridization. The majority of the novel snoRNA genes were found in new gene clusters or as part of previously described clusters. These results expand the repertoire of Arabidopsis snoRNAs to 188 snoRNA genes with 294 gene variants.
小核仁 RNA（snoRNA）和小 Cajal 体特异性 RNA（scaRNA）是非编码 RNA，其在真核生物中的主要功能分别是指导核糖体和剪接体小核 RNA 中核苷酸的修饰。从小核仁细胞培养物分离的核仁 RNA 构建的加帽和未加帽的小 RNA cDNA 文库中，已获得拟南芥 snoRNA 和 scaRNA 的全长序列。我们已鉴定出 31 个新 snoRNA 基因（9 个 box C/D 和 22 个 box H/ACA）和 15 个先前描述 snoRNA 的新变体。三个具有独特基因组织和结构的相关加帽 snoRNA 被鉴定为动物 U13 snoRNA 的同源物。此外，8 个新基因与 rRNA 或 snRNA 没有互补性，因此是潜在的孤儿 snoRNA，可能反映了这些 RNA 的更广泛功能。通过原位杂交证实了一些 snoRNA 的核仁定位和两个推定的 scaRNA 到核体的定位。大多数新 snoRNA 基因位于新的基因簇中或作为先前描述的簇的一部分。这些结果将拟南芥 snoRNA 的种类扩展到 188 个 snoRNA 基因和 294 个基因变体。
