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@article{339172, author = {Říha, Karel and McKnight, Thomas and Fajkus, Jiří and Vyskot, Boris and Shippen, Dorothy E.}, article_location = {Velká Británie}, article_number = {5}, keywords = {telomere; telomerase; Silene latifolia; Arabidopsis thaliana; DNA replication}, language = {eng}, issn = {0960-7412}, journal = {The Plant Journal}, title = {Analysis of the G-overhang structures on plant telomeres: evidence for two distinct telomere architectures}, volume = {23}, year = {2000} }
TY - JOUR ID - 339172 AU - Říha, Karel - McKnight, Thomas - Fajkus, Jiří - Vyskot, Boris - Shippen, Dorothy E. PY - 2000 TI - Analysis of the G-overhang structures on plant telomeres: evidence for two distinct telomere architectures JF - The Plant Journal VL - 23 IS - 5 SP - 633 EP - 633 PB - Blackwell Science Ltd SN - 09607412 KW - telomere KW - telomerase KW - Silene latifolia KW - Arabidopsis thaliana KW - DNA replication N2 - Telomeres are highly conserved structures essential for maintaining the integrity of eukaryotic genomes. In yeast, ciliates and mammals, the G-rich strand of the telomere forms a 3' overhang on the chromosome terminus. Here we investigate the architecture of telomeres in the dicot plants Silene latifolia and Arabidopsis thaliana using the PENT (primer extension/nick translation) assay. We show that both Arabidopsis and Silene telomeres carry G-overhangs longer than 20-30 nucleotides. However, in contrast to yeast and ciliate telomeres, only half of the telomeres in Silene seedlings possess detectable G-overhangs. PENT reactions using a variety of primers and reaction conditions revealed that the remaining fraction of Silene telomeres carries either no overhangs or overhangs less than 12 nucleotides in length. G-overhangs were observed in Silene seeds and leaves, tissues that lack telomerase activity. These findings suggest that incomplete DNA replication of the lagging strand, rather than synthesis by telomerase, is the primary mechanism for G-overhang synthesis in plants. Unexpectedly, we found that the fraction of telomeres with detectable G-overhangs decreased from 50% in seedlings to 35% in leaves. The difference may reflect increased susceptibility of the G-overhangs to nuclease attack in adult leaves, an event that could act as a precursor for the catabolic processes accompanying leaf senescence ER -
ŘÍHA, Karel, Thomas MCKNIGHT, Jiří FAJKUS, Boris VYSKOT and Dorothy E. SHIPPEN. Analysis of the G-overhang structures on plant telomeres: evidence for two distinct telomere architectures. \textit{The Plant Journal}. Velká Británie: Blackwell Science Ltd, 2000, vol.~23, No~5, p.~633-641. ISSN~0960-7412.
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