Telomeres in plants with hypomethylated genomes
| Autoři | |
|---|---|
| Rok publikování | 2014 |
| Druh | Další prezentace na konferencích |
| Citace | |
| Popis | Telomeres are nucleoprotein terminal structures at linear eukaryotic DNA chromosomes, formed by minisatellite DNA repeat sequences. Telomeres play essential roles in cells. They are necessary for the maintenance of genome stability: compensating for the replicative loss of DNA; preventing chromosome fusions; distinguishing natural chromosome ends from double-strand breaks. Telomeres were considered as typical heterochromatic loci with heterochromatin-specific epigenetic marks, but recent studies showed that telomeres of Arabidopsis thaliana associate with both heterochromatin- and euchromatin- specific histone modifications (Vrbsky et al., 2010). Another study even characterized Arabidopsis telomeres as predominantly euchromatic structures (Vaquero-Sedas et al., 2011). We examined length and methylation of telomeres in Arabidopsis thaliana plants germinated in the presence of hypomethylation drugs zebularine and DHPA (dihydroxypropyladenine). Zebularine inhibits DNA methyltransferases, and DHPA is an inhibitor of S-adenosyl-L-homocysteine hydrolase. In seedlings germinated in the presence of hypomethylation agents significantly lower level of methylated cytosines in telomeric and centromeric repetitive sequences was observed, while in adult plants which were grown without the drugs presence, the methylation was almost comparable to that in control samples. In treated plants distinctly shortened telomeres were observed. Short telomere phenotype persisted to the next generation of plants, which grew without the presence of drugs. |
| Související projekty: |