Chromosome Dynamics Laboratory, RIKEN Advanced Science Institute, Saitama, Japan.
Genes Dev. 2011 Jul 15;25(14):1464-9. doi: 10.1101/gad.2060311. Epub 2011 Jun 29.
To understand how chromosome shapes are determined by actions of condensins and cohesin, we devised a series of protocols in which their levels are precisely changed in Xenopus egg extracts. When the relative ratio of condensin I to II is forced to be smaller, embryonic chromosomes become shorter and thicker, being reminiscent of somatic chromosomes. Further depletion of condensin II unveils its contribution to axial shortening of chromosomes. Cohesin helps juxtapose sister chromatid arms by collaborating with condensin I and counteracting condensin II. Thus, chromosome shaping is achieved by an exquisite balance among condensin I and II and cohesin.
为了了解凝聚素和黏合蛋白如何决定染色体的形状，我们设计了一系列实验方案，在爪蟾卵提取物中精确改变它们的水平。当凝聚素 I 与 II 的相对比例被迫变小时，胚胎染色体变短变厚，类似于体细胞染色体。进一步耗尽凝聚素 II 揭示了它对染色体轴向缩短的贡献。黏合蛋白通过与凝聚素 I 合作并拮抗凝聚素 II 来帮助姊妹染色单体臂并置。因此，通过凝聚素 I 和 II 以及黏合蛋白之间的微妙平衡来实现染色体的塑形。
