Telomere
Mostrando 37-48 de 907 artigos, teses e dissertações.
-
37. Length Regulation and Dynamics of Individual Telomere Tracts in Wild-Type Arabidopsis
Although length of the telomeric DNA tract varies widely across evolution, a species-specific set point is established and maintained by unknown mechanisms. To investigate how telomere length is controlled in Arabidopsis thaliana, we analyzed bulk telomere length in 14 wild-type accessions. We found that telomere tracts in Arabidopsis are fairly uniformly di
American Society of Plant Biologists.
-
38. Sua5p a single-stranded telomeric DNA-binding protein facilitates telomere replication
In budding yeast Saccharomyces cerevisiae, telomere length maintenance involves a complicated network as more than 280 telomere maintenance genes have been identified in the nonessential gene deletion mutant set. As a supplement, we identified additional 29 telomere maintenance genes, which were previously taken as essential genes. In this study, we report a
Nature Publishing Group.
-
39. Telomere length is reset during early mammalian embryogenesis
The enzyme telomerase is active in germ cells and early embryonic development and is crucial for the maintenance of telomere length. Whereas the different length of telomeres in germ cells and somatic cells is well documented, information on telomere length regulation during embryogenesis is lacking. In this study, we demonstrate a telomere elongation progra
National Academy of Sciences.
-
40. Euplotes crassus has genes encoding telomere-binding proteins and telomere-binding protein homologs.
We have identified two 1.6 kb macronuclear DNA molecules from Euplotes crassus that hybridize to the alpha subunit of the Oxytricha telomere protein. We have shown that one of these molecules encodes the 51 kDa Euplotes telomere protein while the other appears to encode a homolog of the telomere protein. Although this homolog clearly differs in sequence from
-
41. Counting of Rif1p and Rif2p on Saccharomyces cerevisiae Telomeres Regulates Telomere Length†
Telomere length is negatively regulated by proteins of the telomeric DNA-protein complex. Rap1p in Saccharomyces cerevisiae binds the telomeric TG1-3 repeat DNA, and the Rap1p C terminus interacts with Rif1p and Rif2p. We investigated how these three proteins negatively regulate telomere length. We show that direct tethering of each Rif protein to a telomere
American Society for Microbiology.
-
42. Repair of Chromosome Ends after Telomere Loss in Saccharomyces
Removal of a telomere from yeast chromosome VII in a strain having two copies of this chromosome often results in its loss. Here we show that there are three pathways that can stabilize this broken chromosome: homologous recombination, nonhomologous end joining, and de novo telomere addition. Both in a wild-type and a recombination deficient rad52 strain, mo
The American Society for Cell Biology.
-
43. Regulation of Telomere Length by Checkpoint Genes in Schizosaccharomyces pombe
We have studied telomere length in Schizosaccharomyces pombe strains carrying mutations affecting cell cycle checkpoints, DNA repair, and regulation of the Cdc2 protein kinase. Telomere shortening was found in rad1, rad3, rad17, and rad26 mutants. Telomere lengths in previously characterized rad1 mutants paralleled the replication checkpoint proficiency of t
The American Society for Cell Biology.
-
44. Telomere Folding Is Required for the Stable Maintenance of Telomere Position Effects in Yeast
Yeast telomeres reversibly repress the transcription of adjacent genes, a phenomenon called telomere position effect (TPE). TPE is thought to result from Rap1 and Sir protein-mediated spreading of heterochromatin-like structures from the telomeric DNA inwards. Because Rap1p is associated with subtelomeric chromatin as well as with telomeric DNA, yeast telome
American Society for Microbiology.
-
45. Dissociation of telomerase activity and telomere length maintenance in primitive human hematopoietic cells
Primitive human hematopoietic cells have low endogenous telomerase activity, yet telomeres are not maintained. In contrast, ectopic telomerase expression in fibroblasts and other cells leads to telomere length maintenance or elongation. It is unclear whether this disparity can be attributed to telomerase level or stems from fundamentally different telomere b
National Academy of Sciences.
-
46. Mechanisms underlying telomere repeat turnover, revealed by hypervariable variant repeat distribution patterns in the human Xp/Yp telomere.
Sequences immediately adjacent to the human Xp/Yp telomere exhibit a high frequency of base substitutional polymorphisms, together with almost complete linkage disequilibrium, to create only a few diverged haplotypes. This sequence divergence has been used to develop a PCR-based system for mapping the distribution of the telomere (TTAGGG) and variant repeats
-
47. Effect of telomere length on telomeric gene expression.
Telomeres gradually shorten as human somatic cells divide and a correlation has been observed between the average telomere length and cell senescence. It has been proposed that the genes responsible for cell senescence are located near the telomere and are activated when telomere length reaches a critical point. This is consistent with evidence from Saccharo
-
48. Chlamydomonas telomere sequences are A+T-rich but contain three consecutive G-C base pairs.
We have isolated telomeric DNA and telomere-associated sequences from Chlamydomonas reinhardtii. The terminal telomere sequences of the green alga Chlamydomonas are composed of (TTTTAGGG)n repeats that are similar, but not identical, to those of the higher plant Arabidopsis thaliana. We demonstrate that these repeats are telomeric by their preferential sensi