RNomics in Drosophila melanogaster:: identification of 66 candidates for novel non-messenger RNAs
RNomics in Drosophila melanogaster:: identification of 66 candidates for novel non-messenger RNAs
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DOI：
10.1093/nar/gkg361
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发表时间：
2003-05-15
影响因子：
14.9
通讯作者：
Hüttenhofer, A
中科院分区：
文献类型：
--
作者：
Yuan, GZ;Klämbt, C;Hüttenhofer, A
通过从黑腹果蝇的四个不同发育阶段生成专门的 cDNA 文库，我们鉴定了 66 个小非信使 RNA (snmRNA) 候选者，并通过 Northern 印迹分析证实了它们的表达。其中 13 个仅在黑腹果蝇发育的某些阶段表达。 35 个物种属于小核仁 RNA (snoRNA) 类，分为 C/D 亚类 15 个成员和 H/ACA 亚类 20 个成员，主要分别指导 rRNA 和 snRNA 的 2'-O-甲基化和假尿苷化。其中还包括两个出色的 C/D snoRNA，U3 和 U14，两者均充当前 rRNA 伴侣。令人惊讶的是，果蝇 U14 snoRNA 的序列反映了双翅目中该 snoRNA 相对于酵母和脊椎动物的功能发生了重大变化。在缺乏已知序列和结构基序的22个snmRNA中，5个位于基因间区域，2个位于内含子，5个位于mRNA的非翻译区域，8个来自开放阅读框，2个与内含子相反转录。有趣的是，检测到该组中的两种 RNA 种类意味着某些 snmRNA 种类是由选择性剪接的前 mRNA 加工而成的。令人惊讶的是，在已发表的黑腹果蝇基因组中找不到一些 snmRNA 序列，这可能表明更多的 snmRNA 基因（以及 mRNA）隐藏在基因组的未测序区域中。
By generating a specialised cDNA library from four different developmental stages of Drosophila melanogaster, we have identified 66 candidates for small non-messenger RNAs (snmRNAs) and have confirmed their expression by northern blot analysis. Thirteen of them were expressed at certain stages of D.melanogaster development, only. Thirty-five species belong to the class of small nucleolar RNAs (snoRNAs), divided into 15 members from the C/D subclass and 20 members from the H/ACA subclass, which mostly guide 2'-O-methylation and pseudouridylation, respectively, of rRNA and snRNAs. These also include two outstanding C/D snoRNAs, U3 and U14, both functioning as pre-rRNA chaperones. Surprisingly, the sequence of the Drosophila U14 snoRNA reflects a major change of function of this snoRNA in Diptera relative to yeast and vertebrates. Among the 22 snmRNAs lacking known sequence and structure motifs, five were located in intergenic regions, two in introns, five in untranslated regions of mRNAs, eight were derived from open reading frames, and two were transcribed opposite to an intron. Interestingly, detection of two RNA species from this group implies that certain snmRNA species are processed from alternatively spliced pre-mRNAs. Surprisingly, a few snmRNA sequences could not be found on the published D.melanogaster genome, which might suggest that more snmRNA genes (as well as mRNAs) are hidden in unsequenced regions of the genome.