The Caenorhabditis elegans model has greatly contributed to the understanding of the role of G-quadruplexes in genomic instability. The GGCTTA repeats of the C. elegans telomeres resemble the GGGTTA repeats of the human telomeres. However, the comparison of telomeric sequences (Homo sapiens, Tetrahymena, Oxytricha, Bombyx mori and Giardia) revealed that small changes in these repeats can drastically change the topology of the folded G-quadruplex. In the present work we determined the structure adopted by the C. elegans telomeric sequence d[GG(CTTAGG)3]. The investigated C. elegans telomeric sequence is shown to fold into an intramolecular two G-tetrads basket type G-quadruplex structure that includes a C–T base pair in the diagonal loop. This work sheds light on the telomeric structure of the widely used C. elegans animal model.

中文翻译：

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线虫端粒重复的 G-四联体结构：由非规范 C-T 碱基对稳定的两个四分体篮式构象


秀丽隐杆线虫模型极大地促进了对 G-四链体在基因组不稳定性中的作用的理解。线虫端粒的 GGCTTA 重复序列类似于人类端粒的 GGGTTA 重复序列。然而，端粒序列（智人、四膜虫、尖毛虫、家蚕和贾第鞭毛虫）的比较表明，这些重复序列的微小变化可以极大地改变折叠的 G-四链体的拓扑结构。在目前的工作中，我们确定了线虫端粒序列 d[GG(CTTAGG)3] 采用的结构。研究表明，线虫端粒序列折叠成分子内两个 G-四分体篮型 G-四联体结构，其中对角环中包含一个 C-T 碱基对。这项工作揭示了广泛使用的线虫动物模型的端粒结构。