Larionov V, Kouprina N, Karpova T
Gene. 1984 May;28(2):229-35. doi: 10.1016/0378-1119(84)90260-9.
The mitotic stabilities of hybrid plasmid Rcp21/11, which contains the replicator of yeast rDNA, have been compared for four yeast host strains of different origins. In two related strains, Saccharomyces cerevisiae. A62-1G-P188 and 1A-P3812 from the Peterhof genetic stocks, the plasmid was much more stable than in strains DC5 and GRF18 from the USA stocks. The enhanced mitotic stability of Rcp21/11 in these two yeast strains is obviously attributable to a higher rate of integration of the plasmid into the chromosomal rDNA repeats of the hosts. The centromeric locus CEN3 was inserted into Rcp21/11 because it provides high mitotic and meiotic stability of plasmids with yeast replicators, due to an ordered distribution of plasmids throughout cell division. Using the new centromeric plasmid RcpCEN3, transformation of the four above-described yeast strains was carried out. It was found that, similarly to centromeric plasmids with other chromosomal replicators, RcpCEN3 remains in the cell as a single copy. In strains DC5, GRF18 and A62-1G-P188 the mitotic stability of RcpCEN3 was 20-50%, i.e., less than half that of plasmids containing locus CEN3 and other yeast replicators, ars1, ars2 and the 2mu DNA replicator. The mitotic stability of RcpCEN3 in strains 1A-P3812 (from the Peterhof genetic stocks) for individual clones reached 85%, i.e. close to that of the other plasmids. Genetic analysis showed that the capacity of strain 1A-P3812 to stably retain RcpCEN3 has a recessive polygenic character. We suggest that the observed differences in mitotic stability of centromeric plasmid RcpCEN3 between various yeast strains reflects the differences in activity of rDNA replicator in these strains.(ABSTRACT TRUNCATED AT 250 WORDS)
已对含有酵母rDNA复制子的杂种质粒Rcp21/11在四种不同来源的酵母宿主菌株中的有丝分裂稳定性进行了比较。在两种相关菌株，即来自彼得霍夫遗传品系的酿酒酵母A62-1G-P188和1A-P3812中，该质粒比来自美国品系的DC5和GRF18菌株更稳定。Rcp21/11在这两种酵母菌株中有丝分裂稳定性的增强显然归因于质粒整合到宿主染色体rDNA重复序列中的速率更高。着丝粒位点CEN3被插入到Rcp21/11中，因为它能使带有酵母复制子的质粒在有丝分裂和减数分裂中具有较高的稳定性，这是由于质粒在整个细胞分裂过程中有序分布。使用新的着丝粒质粒RcpCEN3对上述四种酵母菌株进行了转化。结果发现，与带有其他染色体复制子的着丝粒质粒类似，RcpCEN3以单拷贝形式存在于细胞中。在DC5、GRF18和A62-1G-P188菌株中，RcpCEN3的有丝分裂稳定性为20%-50%，即低于含有位点CEN3和其他酵母复制子（ars1、ars2和2μDNA复制子）的质粒的一半。RcpCEN3在1A-P3812菌株（来自彼得霍夫遗传品系）中单个克隆的有丝分裂稳定性达到85%，即接近其他质粒。遗传分析表明，1A-P3812菌株稳定保留RcpCEN3的能力具有隐性多基因特征。我们认为，观察到的着丝粒质粒RcpCEN3在不同酵母菌株中有丝分裂稳定性的差异反映了这些菌株中rDNA复制子活性的差异。（摘要截短于250字）
