Masters M
Mol Gen Genet. 1975 Dec 30;143(1):105-11. doi: 10.1007/BF00269427.
F' strains of E. coli have been isolated which are merodiploid for various chromosomal segments between 66 and 78 minutes. Strains diploid for the chromosomal DNA between the genes bgl and mtl grow slowly, have a reduced DNA/mass and an increased cell size. These properties could result if the chromosomal replication origin and a second, extrachromosomal, copy of the origin (located in this case on the F') were to compete for a substance required to initiate replication. We therefore suggest that these strains are diploid for the chromosomal origin of replication and that, therefore, the origin is located between bgl and mtl, that is between 71 and 73 minutes on the E. coli chromosome.
已分离出大肠杆菌的F'菌株，这些菌株对于66至78分钟之间的各种染色体片段是部分二倍体。对于基因bgl和mtl之间的染色体DNA为二倍体的菌株生长缓慢，DNA/质量降低且细胞大小增加。如果染色体复制起点和第二个位于染色体外的复制起点（在这种情况下位于F'上）竞争启动复制所需的物质，就可能导致这些特性。因此，我们认为这些菌株对于染色体复制起点是二倍体，所以该起点位于bgl和mtl之间，即在大肠杆菌染色体的71至73分钟之间。
