Wilmen A, Hegemann J H
Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität, Frankfurter Strasse 107, D-35392 Giessen, Germany.
Chromosoma. 1996 Apr;104(7):489-503. doi: 10.1007/BF00352113.
We have analysed the centromeric chromatin from chromosome XIV of Saccharomyces cerevisiae at different stages of mitosis with the help of mutants of the cell division cycle. The pattern of centromeric chromatin in cells arrested using cdc20-1, tub2-401 and cdc15-1 alleles was indistinguishable from that of vegetatively growing cells, indicating that the centromeric complex is constitutively present during mitosis and possibly throughout the entire cell cycle. In contrast chromatin isolated from G0 cells and spores exhibited distinct differences in centromeric chromatin probably due to structural rearrangements of the centromeric complex. In particular the alterations found in spores are indicative of an inactive centromeric complex. The differences in centromeric chromatin in spores do not reflect a general reorganisation of the chromatin in this cell type, as the chromatin structure of the PHO3/PHO5 locus in spores was found to be identical to that in vegetative cells under repressed conditions. Thus the structural analysis of the centromere in different cell types provides evidence about the requirement of CEN DNA/protein complexes in different cell types and in different stages of the cell cycle.
我们借助细胞分裂周期的突变体，分析了酿酒酵母第十四号染色体在有丝分裂不同阶段的着丝粒染色质。使用cdc20 - 1、tub2 - 401和cdc15 - 1等位基因使细胞停滞时，着丝粒染色质的模式与营养生长细胞的模式无法区分，这表明着丝粒复合体在有丝分裂期间以及可能在整个细胞周期中持续存在。相比之下，从G0期细胞和孢子中分离出的染色质在着丝粒染色质方面表现出明显差异，这可能是由于着丝粒复合体的结构重排所致。特别是在孢子中发现的变化表明着丝粒复合体处于无活性状态。孢子中着丝粒染色质的差异并不反映这种细胞类型中染色质的一般重组，因为在抑制条件下，发现孢子中PHO3/PHO5基因座的染色质结构与营养细胞中的相同。因此，对不同细胞类型中着丝粒的结构分析提供了关于不同细胞类型以及细胞周期不同阶段中CEN DNA/蛋白质复合体需求的证据。
