Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Universidad Autónoma de Madrid, Nicolás Cabrera 1, 28049 Madrid, Spain.
Genome Biol Evol. 2013;5(6):1142-50. doi: 10.1093/gbe/evt079.
The transition of an ancestral circular genome to multiple linear chromosomes was crucial for eukaryogenesis because it allowed rapid adaptive evolution through aneuploidy. Here, we propose that the ends of nascent linear chromosomes should have had a dual function in chromosome end protection (capping) and chromosome segregation to give rise to the "proto-telomeres." Later on, proper centromeres evolved at subtelomeric regions. We also propose that both noncanonical structures based on guanine-guanine interactions and the end-protection proteins recruited by the emergent telomeric heterochromatin have been required for telomere maintenance through evolution. We further suggest that the origin of Drosophila telomeres may be reminiscent of how the first telomeres arose.
原核生物祖先环状基因组向多个线性染色体的转变对于真核生物的起源至关重要，因为它允许通过非整倍体快速适应进化。在这里，我们提出新生线性染色体的末端应该具有双重功能，即染色体末端保护（端粒加帽）和染色体分离，从而产生“原端粒”。后来，适当的着丝粒在端粒区域进化而来。我们还提出，基于鸟嘌呤-鸟嘌呤相互作用的非典型结构和新兴端粒异染色质募集的端粒保护蛋白都需要通过进化来维持端粒。我们进一步提出，果蝇端粒的起源可能类似于第一个端粒的出现方式。
