Uzawa S, Yanagida M
Department of Biophysics, Faculty of Science, Kyoto University, Japan.
J Cell Sci. 1992 Feb;101 ( Pt 2):267-75. doi: 10.1242/jcs.101.2.267.
The nucleolar and centromeric DNAs of the fission yeast Schizosaccharomyces pombe were visualized in the nucleus by fluorescence in situ hybridization using repetitive ribosomal and centromeric DNAs as the probes. The rDNAs were seen in the nuclear domain previously assigned as nucleolar, that is, the region into which the rod-like chromatin protrudes from the hemispherical chromosomal domain. Using mitotically-arrested cells containing condensed chromosomes, it was demonstrated that the rDNAs were present on the smallest chromosome III, consistent with genetic data. Using a centromeric repetitive element as the hybridization probe, the centromere of chromosome III, cen3, which contains the largest number of the repetitive elements, was visualized. The centromere in interphase cells is located near the periphery of the nucleus as a single dot. Early in mitosis, however, it divides into two and is situated in the middle of the short mitotic spindle. After spindle extension in anaphase, the centromeric DNA is present at both ends of the spindle, that is, near the spindle pole bodies. The movement of cen3 during mitosis (anaphase A and B) is discussed in relation to spindle dynamics and chromosome separation.
利用重复的核糖体DNA和着丝粒DNA作为探针，通过荧光原位杂交技术，在裂殖酵母粟酒裂殖酵母的细胞核中观察到了核仁DNA和着丝粒DNA。核糖体DNA出现在先前被认定为核仁的核区域，即杆状染色质从半球形染色体区域伸出的区域。利用含有浓缩染色体的有丝分裂停滞细胞，证实核糖体DNA存在于最小的第三条染色体上，这与遗传数据一致。以着丝粒重复元件作为杂交探针，观察到了第三条染色体的着丝粒cen3，它含有数量最多的重复元件。间期细胞中的着丝粒作为单个点位于细胞核周边附近。然而，在有丝分裂早期，它会一分为二，位于短有丝分裂纺锤体的中部。在后期纺锤体延长后，着丝粒DNA出现在纺锤体的两端，即靠近纺锤极体的位置。本文讨论了cen3在有丝分裂（后期A和后期B）过程中的移动与纺锤体动力学和染色体分离的关系。
