Administrative Equipment Supplement for GM135470

摘要 大多数物种的端粒是简单的重复序列，由从头开始的端粒重复维持 由核糖核蛋白端粒酶加成。由完美端粒重复组成的小RNA已经被 在几种生物体中观察到，但其功能尚不清楚。我们发现了一种内源性C. 在没有端粒酶的情况下促进端粒稳定的线虫小RNA途径。线虫体型小 与端粒DNA完全互补的RNA非常罕见，每1000万个小分子中就有一个读数 RNA。然而，两个相关的线虫物种，布氏线虫和雷曼线虫，都有端粒小RNA。 增加了几个数量级的水平。三种炎组织中的端粒小RNA 线虫的主要小RNA物种严重缺乏5‘鸟嘌呤核苷酸 比如26G和22G的RNA。综上所述，这些结果表明，端粒小RNA具有明显的生物发生 它们在端粒上的作用可能在最近的几年中发生了戏剧性的变化 线虫进化。我们建议研究小RNA与端粒生物学之间的关系 这些线虫物种，为了努力了解是什么调节端粒小RNA的丰度，如何 端粒小RNA被创造出来，它们的功能是什么。潜在相似的端粒小RNA 已经在纤毛虫和哺乳动物中观察到，我们可能有助于阐明它们的生物学相关性。

Summary Telomeres of most species are simple repetitive sequences that are maintained by de novo telomere repeat addition by the ribonucleoprotein telomerase. Small RNAs composed of perfect telomere repeats have been observed in several organisms, but their functions are not well understood. We discovered an endogenous C. elegans small RNA pathway that promotes telomere stability in the absence of telomerase. C. elegans small RNAs that are perfectly complementary to telomeric DNA are very rare, measuring 1 read per 10 million small RNAs. However, two related Caenorhabditis species, C. briggsae and C. remanei, have telomeric small RNA levels that are increased by several orders of magnitude. Telomeric small RNAs in all three Caenorhabditis species are strongly depleted for 5' guanine nucleotides that characterize major C. elegans small RNA species like 26G and 22G RNAs. Together, these results suggest that telomeric small RNAs have a distinct biogenesis mechanism and that a dramatic change in their role at telomeres may have occurred during recent Caenorhabditis evolution. We propose to study the relationship between small RNAs and telomere biology in these Caenorhabditis species, in an effort to understand what regulates telomeric small RNA abundance, how telomeric small RNAs are created, and what their functions are. Potentially analogous telomeric small RNAs have been observed in ciliates and mammals, and we may help to elucidate their biological relevance.