Evolutionary descent of a human chromosome 6 neocentromere: A jump back to 17 million years ago
Evolutionary descent of a human chromosome 6 neocentromere: A jump back to 17 million years ago
复制标题
DOI：
10.1101/gr.085688.108
复制
发表时间：
2009-05-01
期刊：
影响因子：
7
通讯作者：
Rocchi, Mariano
中科院分区：
文献类型：
--
作者：
Capozzi, Oronzo;Purgato, Stefania;Rocchi, Mariano
分子细胞遗传学提供了生命树的视觉、图画记录，在这方面，人类 2 号染色体的融合起源是一个众所周知的范例。在这里，我们报告了 6 号染色体的变异，其中着丝粒跳跃到 6p22.1。使用针对着丝粒蛋白 CENP-A 和 CENPC 的抗体进行 ChIP 芯片实验，准确地将新着丝粒定义为位于 chr6:26,407-26,491 kb。我们详细研究了灵长类动物6号染色体的进化史，发现灵长类祖先有一条同源染色体，标记顺序相同，但着丝粒位于6p22.1。 17 至 2300 万年前的某个时间 (Mya)，在人类和猿类的共同祖先中，6 号染色体的着丝粒从 6p22.1 移动到当前位置。因此，我们发现的新着丝粒已经跳回到祖先位置，在那里潜在的着丝粒形成潜力持续了至少 17 Myr。正如达尔文首先设想的那样，所有生物体都形成生命之树，因此进化观点可以为当代基因组现象提供令人信服的潜在解释基础。
Molecular cytogenetics provides a visual, pictorial record of the tree of life, and in this respect the fusion origin of human chromosome 2 is a well-known paradigmatic example. Here we report on a variant chromosome 6 in which the centromere jumped to 6p22.1. ChIP-chip experiments with antibodies against the centromeric proteins CENP-A and CENPC exactly defined the neocentromere as lying at chr6:26,407-26,491 kb. We investigated in detail the evolutionary history of chromosome 6 in primates and found that the primate ancestor had a homologous chromosome with the same marker order, but with the centromere located at 6p22.1. Sometime between 17 and 23 million years ago (Mya), in the common ancestor of humans and apes, the centromere of chromosome 6 moved from 6p22.1 to its current location. The neocentromere we discovered, consequently, has jumped back to the ancestral position, where a latent centromere-forming potentiality persisted for at least 17 Myr. Because all living organisms form a tree of life, as first conceived by Darwin, evolutionary perspectives can provide compelling underlying explicative grounds for contemporary genomic phenomena.