Administrative Equipment Supplement for GM135470

总结 大多数物种的端粒是由端粒重复序列维持的简单重复序列 添加的核糖核蛋白端粒酶。由完美的端粒重复序列组成的小RNA已经被发现， 在几种生物中观察到，但它们的功能还不清楚。我们发现了一个内源性的C。 线虫的小RNA途径，促进端粒的稳定性，在端粒酶的情况下。C.小丽鱼 与端粒DNA完全互补的RNA非常罕见，每1000万个小RNA中只有1个读段 RNA。然而，两个相关的小杆线虫种，C. briggsae和C. remanei，具有端粒小RNA 会增加几个数量级。端粒小RNA在所有三个小杆线虫 物种的5'鸟嘌呤核苷酸被强烈耗尽，这是主要C的特征。线虫小RNA种类 比如26G和22G RNA总之，这些结果表明端粒小RNA具有独特的生物起源， 在最近的研究中，端粒的作用可能发生了戏剧性的变化。 小杆线虫进化我们建议研究小RNA和端粒生物学之间的关系， 这些小杆线虫物种，在努力了解是什么调节端粒小RNA丰度，如何 端粒小RNA的产生，以及它们的功能。可能类似的端粒小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.