Max-Planck-Institut für Biochemie, D-8033 Martinsried bei München, FRG.
EMBO J. 1983;2(4):515-9. doi: 10.1002/j.1460-2075.1983.tb01456.x.
A plasmid has been discovered in a strain of the eukaryote, Dictyostelium discoideum, which has an unstable, non-chromosomal, cobalt resistance phenotype. The plasmid, termed Ddp1, is 13.5 kbp in size and is found in the nucleus. It has an A-T content typical of Dictyostelium DNA as judged by its restriction enzyme digestion pattern, and it is not related to either mitochondrial or ribosomal DNA. Similar or identical plasmids have been found in two original, cobalt-sensitive, isolates, NC4 and V12, but no plasmid was detected in three other isolates (WS472, WS526, WS584). The plasmid codes for non-essential functions since it is absent from the latter isolates, and it is lost from mutant strains which are capable of axenic growth.
已经在真核生物盘基网柄菌（Dictyostelium discoideum）的一个菌株中发现了一种质粒，该质粒具有不稳定的非染色体钴抗性表型。该质粒称为 Ddp1，大小为 13.5 kbp，存在于核内。根据其限制酶消化图谱判断，它的 A-T 含量是典型的盘基网柄菌 DNA，与线粒体或核糖体 DNA 无关。在两个原始的、钴敏感的分离株 NC4 和 V12 中发现了类似或相同的质粒，但在另外三个分离株（WS472、WS526 和 WS584）中未检测到质粒。该质粒编码非必需功能，因为它不存在于后三个分离株中，而且在能够进行无菌生长的突变株中也会丢失。
