To study the phylogeny and evolution of archiascomycetes, we determined the full sequence of the nuclear 18S rRNA gene from 14 Taphrina species and 2 Protomyces species, and the partial sequence of Schizosaccharomycesjaponicus var.japonicus. The sequences were phylogenetically analyzed by the neighbor-joining, maximum parsimony, and maximum-likelihood methods. We also looked at their principal phenotypic characters and genotypic character.

The significant differences in DNA methylation that are considered to be a biomarker for the diagnosis of cancer are a barrier to the application of biomarkers in the clinical field. In the present study, new primers were designed and further standard controls were set up to validate the accuracy of the methylation‑specific PCR (MSP), a method widely used to analyze DNA methylation. By analyzing the methylation pattern of breast cancer 1 (BRCA1) and estrogen receptor (ER) in 60 patients with breast cancer, the number of cases of methylated BRCA1 and ER detected by the primer was 7/60 and 21/60, respectively, whereas that detected by the previous widely used primers was 25/60 and 47/60, respectively. Sequencing of the MSP products indicated that the 18 and 26 false-positive methylations of BRCA1 and ER, respectively, were due to insufficient validation of the previously used primers. Thus, the present study proposes that all studies based on the MSP approach should incorporate more controls to validate the precision of the MSP primers.

DNA ladder is commonly used to determine the size of DNA fragments by electrophoresis in routine molecular biology laboratories. In this study, we report a new procedure to prepare a DNA ladder that consists of 10 fragments from 100 to 1000 bp. This protocol is a combination of routinely employed methods: cloning, PCR, and partial digestion with restriction enzymes. DNA fragments of 100 bp with unique restriction site at both ends were self-ligated to create a tandem repeat. Once being cloned, the tandem repeat was rapidly amplified by PCR and partially digested by restriction enzymes to produce a ladder containing multimers of the repeated DNA fragments. Our procedure for production of DNA ladder could be simple, time saving, and inexpensive in comparison with current ones widely used in most laboratories.

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The MSP-DB dispels the weakness of MSP and increases the sensitivity to simultaneous methylation analysis of multiple genes. The MSP-DB is advantageous for the promotion of DNA methylation markers in progressing quickly toward clinical application.