HIGH-LEVELS OF CHROMOSOME INSTABILITY IN POLYPLOIDS OF SACCHAROMYCES-CEREVISIAE
HIGH-LEVELS OF CHROMOSOME INSTABILITY IN POLYPLOIDS OF SACCHAROMYCES-CEREVISIAE
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DOI：
10.1016/0027-5107(90)90024-x
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发表时间：
1990-08-01
期刊：
影响因子：
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通讯作者：
AGUILERA, A
中科院分区：
文献类型：
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作者：
MAYER, VW;AGUILERA, A
利用酿酒酵母研究了单细胞生物体中多倍体的遗传后果。构建了具有遗传标记的染色体VII（cyh 2-leu 1-CEN 7-ade 6）的等基因二倍体（2N）、三倍体（3 N）和四倍体（4 N）菌株，并用于跟踪有丝分裂期间一条、两条或三条染色体VII的丢失。我们发现，随着倍性的增加，单个染色体VII的丢失频率增加：染色体VII的一个拷贝的丢失在三倍体中的发生率高出近30倍，在四倍体中比二倍体高出约1000倍。两个或三个拷贝的丢失发生的频率更高。这些发现表明非整倍体（3 N-1、3 N-2、4 N-1、4 N-2、4 N-3）增加了基因组不稳定性，或者多个染色体丢失事件以高频率发生。多倍性似乎显着增加染色体丢失，可能是由于细胞无法进行适当的染色体分离。本文讨论了单细胞生物如酵母多倍体不稳定的生物学意义和可能原因。
The yeast Saccharomyces cerevisiae was used to study the genetic consequences of polyploidy in a unicellular organism. Isogenic diploid (2N), triploid (3N) and tetraploid (4N) strains with a genetically marked chromosome VII (cyh2-leu1-CEN7-ade6) were constructed and were used to follow the loss of one, two or three chromosome VII''s during mitosis. We found that as ploidy increased, the frequency of loss of a single chromosome VII increased: Loss of one copy of chromosome VII occurred at a rate nearly 30-fold higher in triploids and approximately 1000-fold higher in tetraploids than in the diploid. Loss of two or three copies occurred at an even greater frequency. These findings suggest either that aneuploidy (3N-1, 3N-2, 4N-1, 4N-2, 4N-3) increases genome instability or that multiple chromosome loss events occur at high frequency. Polyploidy appears to dramatically increase chromosome loss, presumably due to the inability of the cell to undergo proper chromosome segregation. The biological significance and possible cause for the instability of polyploidy in unicellular organisms such as yeast are discussed.