Berkner Silvia, Lipps Georg
Department of Biochemistry, University of Bayreuth, Universitätsstr. 30, 95447 Bayreuth, Germany.
Extremophiles. 2008 Mar;12(2):263-70. doi: 10.1007/s00792-007-0125-7. Epub 2008 Jan 5.
We have determined the apparent and actual spontaneous mutation frequencies and rates for different species and strains of the thermoacidophilic crenarchaeote Sulfolobus. The proportion of mutations caused by insertion sequences has also been analyzed. Mutation frequencies for S. islandicus (0.08-0.6 mutations per cell division and 10(7) cells) were below those determined for S. solfataricus and comparable to or lower than those for S. acidocaldarius. The proportion of insertion sequence mutations for the S. islandicus strains REN1H1 (9 out of 230) and HVE10/4 (0 out of 24) was found to be considerably lower than in S. solfataricus P1 and P2 and also low in comparison to other S. islandicus strains. Mutants defective in either the pyrEF genes or the lacS gene have been isolated. Their growth phenotype on selective and non-selective medium was examined and the inactivating mutations in either of the genes were determined. In addition the reversion frequencies for these mutants were measured and found to be in the range of <0.6-1.5 mutations per cell division and 10(8) cells. However, when being subjected to electroporation as a transformation procedure, increased reversion was observed.
我们已经确定了嗜热嗜酸泉古菌硫化叶菌不同物种和菌株的表观和实际自发突变频率及速率。还分析了由插入序列引起的突变比例。冰岛硫化叶菌的突变频率（每细胞分裂和10⁷个细胞中有0.08 - 0.6个突变）低于嗜酸热硫化叶菌的测定值，与嗜酸热栖热菌的突变频率相当或更低。发现冰岛硫化叶菌菌株REN1H1（230个中有9个）和HVE10/4（24个中有0个）的插入序列突变比例明显低于嗜酸热硫化叶菌P1和P2，与其他冰岛硫化叶菌菌株相比也较低。已经分离出pyrEF基因或lacS基因有缺陷的突变体。检测了它们在选择性和非选择性培养基上的生长表型，并确定了任一基因中的失活突变。此外，还测量了这些突变体的回复突变频率，发现其范围为每细胞分裂和10⁸个细胞中有<0.6 - 1.5个突变。然而，当作为转化程序进行电穿孔时，观察到回复突变增加。
