Granot D, Snyder M
Department of Biology, Yale University, New Haven, CT 06511.
Cell Motil Cytoskeleton. 1991;20(1):47-54. doi: 10.1002/cm.970200106.
The segregation of the nucleolus during mitosis was examined in Saccharomyces cerevisiae and Schizosaccharomyces pombe by indirect immunofluorescence using antibodies directed to highly conserved anti-nucleolus antigens. In mitotic S. pombe cells, the nucleolus appears to trail the bulk of the DNA. In wild-type cells of S. cerevisiae, the nucleolus segregates alongside the bulk of the genomic DNA. Based on its distance from the centromere, we would expect the rDNA in both organisms to segregate behind the majority of the genomic DNA, if telomeric regions trail centromeric regions as in other eukaryotes. We therefore suggest that in S. cerevisiae the nucleolus is attached to other parts of the nucleus which enable it to segregate along with the bulk of the DNA. The segregation of the nucleolus in topoisomerase mutants and nuclear division mutants of S. cerevisiae was also investigated. In cdc14 mutants which arrest at late anaphase, the vast majority of the DNA is separated, but the nucleolar antigens remain extended between the mother and daughter cells. Thus, the CDC14 gene of S. cerevisiae appears to be important for the separation of the nucleolus at mitosis.
利用针对高度保守的抗核仁抗原的抗体，通过间接免疫荧光法，在酿酒酵母和裂殖酵母中研究了有丝分裂期间核仁的分离情况。在有丝分裂的裂殖酵母细胞中，核仁似乎落后于大部分DNA。在酿酒酵母的野生型细胞中，核仁与大部分基因组DNA一起分离。基于其与着丝粒的距离，如果端粒区域像在其他真核生物中那样落后于着丝粒区域，我们预计这两种生物中的核糖体DNA会在大部分基因组DNA之后分离。因此，我们认为在酿酒酵母中，核仁与细胞核的其他部分相连，这使其能够与大部分DNA一起分离。还研究了酿酒酵母拓扑异构酶突变体和核分裂突变体中核仁的分离情况。在停滞于后期的cdc14突变体中，绝大多数DNA已分离，但核仁抗原仍在母细胞和子细胞之间延伸。因此，酿酒酵母的CDC14基因似乎对有丝分裂时核仁的分离很重要。
