The results obtained in the present study allowed us to dismiss the ����exon 2 splicing���� hypothesis of the mechanism of suppression in brains of 129/J mice. There could, however, be other explanations of the apparent misGvA activity despite the nonsense mutation. It is possible that some MDV3100 CYP17 inhibitor nonsense-suppression mechanism operates in the brain. It is also possible that other inaccurate DNA Pols are more active in the presence of Mg2+ ions than in Mn2+ cations. This misGvA activity may be the result of the transient misalignment or error-prone behavior of Pols, because the substrate used in the aforementioned studies, allows the detection of some misGvA activity due to transient misalignment. In our work, we improved the misGvA technique for specific detection of Pol i replacing Mg2+ by Mn2+ ions in the reaction PI-103 company mixture, adapted the misGvA method to yeast extracts producing human DNA polymerases and demonstrated that this is a simple approach to detect the presence of Pol i activity without time and cost-consuming biochemical manipulations. The purification of the enzyme takes hours and requires several liters of yeast culture. Our method with extracts is robust and the test could be performed only with 10�C20 ml of culture, which is easy to make fresh for each experiment. We propose that the ����misGvA���� method can be applied for detection and fast screening of activity Pol i and study of catalytic properties of its variants in human cancers cell extracts as well as cells harboring Pol i polymorphisms. The modifications of the method with extracts tailored for the detection of different kinds of DNA synthesis errors could be applied also as a simple approach to monitor replication fidelity in cell extracts. The DNA synthesis in yeast extracts producing human Pol i and Pol g was characterized by very low fidelity. This did not directly translate into genomic instability in vivo. We did not observe elevated mutation rates in the yeast strains carrying plasmids expressing genes encoding for human Pol i and Pol g. The results are consistent with the absence of a direct mutator effect in yeast of overproduced yeast Pol g and only mild effects on the protection from DNA damaging agents of repair-defective yeast producing human Pol i. Complex interactions within live cells tightly regulate the access of error-prone Pols to chromatin. Systems of ectopic coexpression of Y-family Pol genes with polymerase accessory factors could potentially help to reveal these regulators. The discovery and use of polymorphic microsatellite loci have had significant effects in many areas of genetic research. For the past two decades they have been the markers of choice in a wide range of forensic profiling, population genetics and wildlife-related research. The importance and applicability of these markers are confirmed by observing an excess of 45,000 hits on the word ����microsatellite���� on the Web of Science database.