Diploid spore formation and other meiotic effects of two cell-division-cycle mutations of Saccharomyces cerevisiae.
Diploid spore formation and other meiotic effects of two cell-division-cycle mutations of Saccharomyces cerevisiae.
复制标题
酿酒酵母两个细胞分裂周期突变的二倍体孢子形成和其他减数分裂效应。
DOI：
10.1093/genetics/96.4.859
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发表时间：
1980
期刊：
影响因子：
3.3
通讯作者：
Byers,B
中科院分区：
文献类型：
--
作者：
Schild,D;Byers,B
已经检查了酿酒酵母的两种细胞分裂周期突变（cdc5和cdc14）的减数分裂效应。这些突变由 L. H. Hartwell 和他的同事分离出来，并被定性为有丝分裂缺陷，导致核分裂后期对温度敏感的停滞。当受到减数分裂中的限制性温度时，这些突变的纯合二倍体细胞通常会进行减数分裂前的 DNA 合成并致力于减数分裂水平的重组，但随后在纺锤体极体 (SPB) 复制和分离后的阶段停滞。这两个 SPB 缺乏完整减数分裂 I 纺锤体典型的纺锤体微管的互连。这些纯合子受到半限制性温度的挑战常常导致含有两个二倍体孢子的子囊的产生。对存活孢子对的遗传分析显示，每个孢子对于着丝粒连锁标记的纯合性显着高于远端标记，表明这两个孢子各自含有在减数分裂 I 的减数分裂中共同分离的姐妹着丝粒对。cdc5 纯合子的超微结构分析表明，这些细胞已完成减数分裂 I 并形成两个减数分裂 II 纺锤体，但后者仍然异常短。这导致每个纺锤体的两个极被封装在单个孢子壁内。因此，这些突变在减数分裂以及最初描述的有丝分裂中都是有缺陷的。
The meiotic effects of two cell-division-cycle mutations ofSaccharomyces cerevisiae(cdc5andcdc14) have been examined. These mutations were isolated by L. H. Hartwell and his colleagues and characterized as defective in mitosis, causing a temperature-sensitive arrest in late nuclear division. When subjected to the restrictive temperature in meiosis, diploid cells homozygous for either of these mutations generally proceeded through premeiotic DNA synthesis and commitment to meiotic levels of recombination, but then arrested at a stage following spindle pole body (SPB) duplication and separation. The two SPBs lacked the interconnection by spindle microtubules typical of the complete meiosis I spindle. Challenge of these homozygotes by a semi-restrictive temperature often caused the production of asci containing two diploid spores. Genetic analysis of the viable pairs of spores revealed that each spore had become homozygous for centromere-linked markers significantly more frequently than for distal markers, indicating that the two spores each contained pairs of sister centromeres that had co-segregated in the reductional division of meiosis I. Ultrastructural analysis of thecdc5homozygote demonstrated that these cells had completed meiosis I and formed two meiosis II spindles, but that the latter remained unusually short. This resulted in the encapsulation of both poles of each spindle within a single spore wall. These mutations therefore are defective in both meiotic divisions, as well as in the mitotic division described originally.