Telomeres and Cancer laboratory, 'Equipe Labellisée Ligue contre le Cancer', UMR3244, Institut Curie, 26 rue d'Ulm, 75248 Paris, France.
Nucleic Acids Res. 2013 May;41(9):4792-801. doi: 10.1093/nar/gkt169. Epub 2013 Mar 21.
In contrast with the limited sequence divergence accumulated after separation of higher primate lineages, marked cytogenetic variation has been associated with the genome evolution in these species. Studying the impact of such structural variations on defined molecular processes can provide valuable insights on how genome structural organization contributes to organismal evolution. Here, we show that telomeres on chromosome arms carrying subtelomeric heterochromatic caps in the chimpanzee, which are completely absent in humans, replicate later than telomeres on chromosome arms without caps. In gorilla, on the other hand, a proportion of the subtelomeric heterochromatic caps present in most chromosome arms are associated with large blocks of telomere-like sequences that follow a replication program different from that of bona fide telomeres. Strikingly, telomere-containing RNA accumulates extrachromosomally in gorilla mitotic cells, suggesting that at least some aspects of telomere-containing RNA biogenesis have diverged in gorilla, perhaps in concert with the evolution of heterochromatic caps in this species.
与高等灵长类动物谱系分离后积累的有限序列差异相比，明显的细胞遗传学变异与这些物种的基因组进化有关。研究这些结构变异对特定分子过程的影响，可以深入了解基因组结构组织如何促进生物进化。在这里，我们表明，在携带端粒上的端粒重复序列的染色体臂上，端粒在黑猩猩中复制得比在人类中更晚，而在人类中则完全不存在。另一方面，在大猩猩中，大多数染色体臂上存在的部分端粒异染色质帽与大片端粒样序列相关，这些序列遵循与真正的端粒不同的复制程序。引人注目的是，端粒包含的 RNA 在大猩猩有丝分裂细胞中积累在染色体外，这表明至少在大猩猩中，端粒包含的 RNA 生物发生的某些方面已经发生了分歧，这可能与该物种异染色质帽的进化有关。
