Saccharomyces telomeres acquire single-strand TG1-3 tails late in S phase.
Saccharomyces telomeres consist of approximately 300 bp of C1-3A/TG1-3 DNA. Nondenaturing Southern hybridization, capable of detecting approximately 60 to approximately 300 bases of TG1-3 DNA, revealed that yeast telomeres acquired and lost TG1-3 tails, the predicted intermediate in telomere replication, in a cell cycle-dependent manner. TG1-3 tails were also detected on the ends of a linear plasmid isolated from late S phase cells. In addition, a nonlinear form of this plasmid was detected: this structure migrated in two-dimensional agarose gels like a nicked circle of the same size as the linear plasmid, but had considerably more single-stranded character than a conventional nicked circle. The evidence indicates that these circles were formed by telomere-telomere interactions involving the TG1-3 tails. These data provide evidence for a cell cycle-dependent change in telomere structure and demonstrate that TG1-3 tails, generated during replication of a linear plasmid in vivo, are capable of mediating telomere-telomere interactions.
Wellinger
R J
RJ
Fred Hutchinson Cancer Research Center, Seattle, Washington.
Wolf
A J
AJ
Zakian
V A
VA
D001482:Base Composition; D015139:Blotting, Southern; D015825:Chromosomes, Fungal; D004271:DNA, Fungal / Q000235:genetics*; D004277:DNA, Single-Stranded / Q000235:genetics*; D004587:Electrophoresis, Agar Gel; D015180:Electrophoresis, Gel, Two-Dimensional; D010957:Plasmids; D012091:Repetitive Sequences, Nucleic Acid; D016196:S Phase / Q000235:genetics*; D012440:Saccharomyces / Q000166:cytology / Q000235:genetics*; D016615:Telomere
D004271:DNA, Fungal; D004277:DNA, Single-Stranded