Trzcinska-Danielewicz J, Kozlowski P, Toczko K
Institute of Biochemistry, Warsaw University, Poland.
Gene. 1996 Feb 22;169(1):143-4. doi: 10.1016/0378-1119(95)00798-9.
We have cloned the genomic copy of the Ppras1 gene, a homologue of the ras proto-oncogene, from the true slime mold Physarum polycephalum. Ppras1 contains five small introns, four of which have a high content of pyrimidines. The (dC)-homopolymers present in introns 4 and 5 may be responsible for the observed recA-independent deletion in Ppras1 upon amplification of the Ppras1-bearing plasmid by choramphenicol. Although Ppras1 exhibits amino acid and nucleotide homologies with the DdrasG gene, a homologue of ras from another slime mold, Distyostelium discoideum, locations and sequences of their introns are quite different. This discordance suggests that introns of the ras genes in these species were acquired independently.
我们已经从黏菌多头绒泡菌中克隆出了原癌基因ras的同源基因Ppras1的基因组拷贝。Ppras1含有5个小内含子，其中4个富含嘧啶。第4和第5内含子中存在的(dC)同聚物可能是在通过氯霉素扩增携带Ppras1的质粒时，Ppras1中观察到的不依赖recA的缺失的原因。尽管Ppras1与另一种黏菌盘基网柄菌的ras同源基因DdrasG在氨基酸和核苷酸上具有同源性，但其内含子的位置和序列却有很大差异。这种不一致表明这些物种中ras基因的内含子是独立获得的。
