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.2007 Mar;27(5):1706-15.
doi: 10.1128/MCB.02059-06. Epub 2006 Dec 22.

Telomere rapid deletion regulates telomere length in Arabidopsis thaliana

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Telomere rapid deletion regulates telomere length in Arabidopsis thaliana

J Matthew Watson et al. Mol Cell Biol.2007 Mar.

Abstract

Telomere length is maintained in species-specific equilibrium primarily through a competition between telomerase-mediated elongation and the loss of terminal DNA through the end-replication problem. Recombinational activities are also capable of both lengthening and shortening telomeres. Here we demonstrate that elongated telomeres in Arabidopsis Ku70 mutants reach a new length set point after three generations. Restoration of wild-type Ku70 in these mutants leads to discrete telomere-shortening events consistent with telomere rapid deletion (TRD). These findings imply that the longer telomere length set point is achieved through competition between overactive telomerase and TRD. Surprisingly, in the absence of telomerase, a subset of elongated telomeres was further lengthened, suggesting that in this background a mechanism of telomerase-independent lengthening of telomeres operates. Unexpectedly, we also found that plants possessing wild-type-length telomeres exhibit TRD when telomerase is inactivated. TRD is stochastic, and all chromosome ends appear to be equally susceptible. The frequency of TRD decreases as telomeres shorten; telomeres less than 2 kb in length are rarely subject to TRD. We conclude that TRD functions as a potent force to regulate telomere length in Arabidopsis.

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Figures

FIG. 1.
FIG. 1.
Telomere length homeostasis and TRD inku70 mutants and rescued plants. (A) FIGE of the wild type (Wt) and successive generations ofku70 mutants. TRF analysis was carried out on DNA extracted from ∼50 seedlings. An asterisk denotes a specific hybridizing signal in the G7 line. (B) Scheme for creatingKU70 rescued plants. G4ku70 mutant plants were transformed with either pCBK21 or pCBK22. Plants selected in the next generation correspond to T1. (C) TRF analysis of nontransformed (NT) and selected plants. (D) Parent-progeny TRF analysis of two independent T1 transformants.
FIG. 2.
FIG. 2.
KU70 is not required for TRD. (A) Schematic diagram for generatingku70 tert double mutants. A plant heterozygous forku70 was crossed to a plant heterozygous fortert. Double heterozygotes for both genes were genotyped in F1. Self-fertilized progeny of the F1 plant were genotyped to identifyku70−/−tert+/− (designated G1). These plants were self-fertilized, and progeny were maintained asku70−/−tert+/− until G4. G4 plants were transformed with pCBK22 prior to segregation fortert. (B) TRF analysis of T1 and nonselected (NS) progeny of a G4 plant transformed with pCBK22. (C) Subtelomere analysis of T1 parents and their T2 progeny. The subtelomere probe used for the experiments is indicated below each blot. The panels represent sequential hybridization of a single membrane.
FIG. 3.
FIG. 3.
TRD inArabidopsis is not dependent upon known recombinases. (A) Genetic scheme for obtainingrad51 mutants with elongated telomeres. Plants null forku70 and heterozygous for the indicated genotypes were transformed with pCBK22, and the transformed progeny were genotyped to identify transformants homozygous null for the indicated genotype. (B) TRF analysis of T1 progeny of the indicated genotypes. Transformants (+) and nontransformants (−) are indicated. (C) Parent progeny subtelomere analysis of a single T1mre11+/− plant. Self-fertilized progeny of this plant were genotyped forMRE11 and for the presence of the pCBK22-derived T-DNA. Arrowheads denote additional products in one of themre11 mutants. The probe is 2R.
FIG. 4.
FIG. 4.
TILT intert mutants with elongated telomeres. (A) Parent progeny subtelomere analysis of a T1 pCBK22 transformant homozygous fortert. Mutants were generated as described in the legend to Fig. 2A. Asterisks denote telomeres that were elongated relative to the parent (P). The hybridizing probe is 1L. (B) Sequential hybridization of three probes to a blot containing a subset of samples from panel A. Lane numbers correspond to numbers from the gel in panel A. Arrowheads denote interstitial hybridizing signals.
FIG. 5.
FIG. 5.
TRD occurs in telomeres within the wild-type range. (A) Representative PETRA data. Changes defined as TRD are indicated by asterisks. The telomere that was monitored is indicated below each lane. (B) Graph depicting the change in telomere length versus generation for different genotypes and their progeny. (B) Graph depicting the change in telomere length from parent to progeny relative to the length of the telomere in the parent.
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References

    1. Ancelin, K., M. Brunori, S. Bauwens, C.-E. Koering, C. Brun, M. Ricoul, J.-P. Pommier, L. Sabatier, and E. Gilson. 2002. Targeting assay to study the cis functions of human telomeric proteins: evidence for inhibition of telomerase by TRF1 and for activation of telomere degradation by TRF2. Mol. Cell. Biol. 22:3474-3487. - PMC - PubMed
    1. Blanc, G., A. Barakat, R. Guyot, R. Cooke, and M. Delseny. 2000. Extensive duplication and reshuffling in the Arabidopsis genome. Plant Cell 12:1093-1101. - PMC - PubMed
    1. Bleuyard, J. Y., M. E. Gallego, F. Savigny, and C. I. White. 2005. Differing requirements for the Arabidopsis Rad51 paralogs in meiosis and DNA repair. Plant J. 41:533-545. - PubMed
    1. Borevitz, J. O., D. Liang, D. Plouffe, H. S. Chang, T. Zhu, D. Weigel, C. C. Berry, E. Winzeler, and J. Chory. 2003. Large-scale identification of single-feature polymorphisms in complex genomes. Genome Res. 13:513-523. - PMC - PubMed
    1. Boulton, S. J., and S. P. Jackson. 1998. Components of the Ku-dependent non-homologous end-joining pathway are involved in telomeric length maintenance and telomeric silencing. EMBO J. 17:1819-1828. - PMC - PubMed

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