Hsiao C L, Carbon J
Gene. 1981 Nov;15(2-3):157-66. doi: 10.1016/0378-1119(81)90125-6.
A yeast DNA sequence (ars2), capable of supporting autonomous replication of plasmids, in yeast, has been characterized. The ars2 replicator occurs about 7 kb from the ARG4 gene on yeast chromosome VIII. Plasmids containing ars2 and the ARG4 gene transform yeast arg4 mutants to ARG4+ with high frequency (about 103 transformants/micrograms DNA) and replicate autonomously in the transformed cells. The ars2 plasmids are mitotically unstable and are readily lost from yeast cultures when grown under nonselective conditions. The addition of a DNA segment containing functional yeast centromere (CEN3) and an ars2 plasmid effectively stabilizes the plasmid against both mitotic and meiotic loss. The ars2-CEN3 minichromosomes replicate autonomously in controlled copy number while segregating in a typical Mendelian pattern (2+ :2-) during meiosis. The requirement for a separate replicator sequence for stable mitotic and meiotic maintenance of centromere-containing minichromosomes is equally satisfied by the presence of either ars1 or ars2. The centromere controls plasmid copy number to a low value (usually one) regardless of the type of replicator used.
一种能够在酵母中支持质粒自主复制的酵母DNA序列（ars2）已得到鉴定。ars2复制子位于酵母VIII号染色体上距ARG4基因约7 kb处。含有ars2和ARG4基因的质粒能以高频率（约103个转化子/微克DNA）将酵母arg4突变体转化为ARG4+，并在转化细胞中自主复制。ars2质粒在有丝分裂时不稳定，在非选择性条件下培养时很容易从酵母培养物中丢失。添加一段含有功能性酵母着丝粒（CEN3）的DNA片段和一个ars2质粒可有效稳定该质粒，防止其在有丝分裂和减数分裂时丢失。ars2 - CEN3微型染色体以可控的拷贝数自主复制，同时在减数分裂过程中以典型的孟德尔模式（2+ : 2-）分离。对于含有着丝粒的微型染色体，无论是ars1还是ars2的存在，都同样满足其在有丝分裂和减数分裂时稳定维持所需的单独复制子序列的要求。无论使用何种类型的复制子，着丝粒都能将质粒拷贝数控制在较低水平（通常为一个）。
