Erratum: The Chromosomal Constitution of Postmitotic Neurons, Assessed by Neuronal Nuclear Transfer into Oocytes and in ES Cell Lines Derived from Them

Spectral karyotyping (SKY) was used to assess the chromosomal constitution of embryos generated by nuclear transfer (NT) of neuronal nuclei (N-NT) or cumulus cell nuclei (C-NT) into oocytes and of their embryonic stem cell derivatives (ntES cells). We detected chromosomal changes during the first mitotic cleavage and in the condensed chromatids of NT embryos. We also found clonal translocations in the ntES cells that were derived from NT embryos cloned from neuronal nuclei. The differentiation potentials of the ntES cells showing chromosomal rearrangements were partly restricted. Our findings indicate that balanced or unbalanced chromosomal translocations can occur in early NT embryogenesis, suggesting that a DNA repair system is activated during both NT embryogenesis and ntES cell establishment. We observed a higher incidence of chromosomal changes in N-NT than in C-NT embryos, which may reflect a higher frequency of double-stranded (ds) DNA breaks in the neuronal genome.

本研究采用光谱核型分析（Spectral karyotyping, SKY）技术，评估了通过神经元细胞核核移植（N-NT）或卵丘细胞核核移植（C-NT）将细胞核注入卵母细胞所获得的胚胎，以及其核移植胚胎干细胞衍生物（ntES细胞）的染色体组成。我们检测了核移植胚胎在首次有丝分裂卵裂阶段及浓缩染色单体中的染色体变异。同时，我们在源自神经元细胞核核移植胚胎的ntES细胞中发现了克隆易位现象。携带染色体重排的ntES细胞，其分化潜能受到部分限制。本研究结果表明，平衡或非平衡染色体易位可发生于早期核移植胚胎发生过程中，这提示核移植胚胎发生与ntES细胞建系过程中均会激活DNA修复系统。我们还观察到，N-NT胚胎的染色体变异发生率高于C-NT胚胎，这一现象可能反映了神经元基因组中双链（ds）DNA断裂的发生频率更高。