LINE-1 methylation status of endogenous DNA double-strand breaks

DNA methylation and the repair of DNA double-strand breaks (DSBs) are important processes for maintaining genomic integrity. Although DSBs can be produced by numerous agents, they also occur spontaneously as endogenous DSBs (EDSBs). In this study, we evaluated the methylation status of EDSBs to determine if there is a connection between DNA methylation and EDSBs. We utilized interspersed repetitive sequence polymerase chain reaction (PCR), ligation-mediated PCR and combined bisulfite restriction analysis to examine the extent of EDSBs and methylation at long interspersed nuclear element-1 (LINE-1) sequences nearby EDSBs. We tested normal white blood cells and several cell lines derived from epithelial cancers and leukemias. Significant levels of EDSBs were detectable in all cell types. EDSBs were also found in both replicating and non-replicating cells. We found that EDSBs contain higher levels of methylation than the cellular genome. This hypermethylation is replication independent and the methylation was present in the genome at the location prior to the DNA DSB. The differences in methylation levels between EDSBs and the rest of the genome suggests that EDSBs are differentially processed, by production, end-modification, or repair, depending on the DNA methylation status.     

Possibility to Apply Strontium Aluminate to Produce Light-Emitting Plants: Efficiency and Safety

Light-emitting plants (LEPs) provides light in areas without electricity. The phosphorescent compound was used as a lighting material for LEP development. However, using the phosphorescent compound for LEPs development required optimization and phytotoxicity evaluation. Strontium aluminate (SrAl₂O₄) is a phosphorescent compound that can glow for a long time and is easily recharged by visible light. In this study, using SrAl₂O₄ to develop LEPs was evaluated. Additionally, plant stress under SrAl₂O₄ was investigated. Metabolomic analysis can explain the possible mechanism of plants’ stress under SrAl₂O₄. After, injecting 3 mL of 5 % (w/v) SrAl₂O₄ products 1, 2, and 3 into the stem of Ipomoea aquatica, the result showed that SrAl₂O₄ products 2 and 3 caused oxidative stress. The metabolomic analysis also indicated that I. aquatica responded to SrAl₂O₄ product 1 by increasing pipecolic acid and salicylic acid, while I. aquatica injected with SrAl₂O₄ products 2 and 3 showed a decrease in salicylic acid around 0.005 and 0.061-fold, respectively, compared to control plants. and an excess accumulation of MDA around 10.00–12.00 μmol g⁻¹ FW. A 15 % concentration of SrAl₂O₄ can be used for LEPs development, enabling photoemission 18-fold for 50 min. SrAl₂O₄ product 1 has the potential to be a material for LEPs.