» Articles » PMID: 12888526

Retrotransposon-mediated Restoration of Chlorella Telomeres: Accumulation of Zepp Retrotransposons at Termini of Newly Formed Minichromosomes

Overview
Specialty Biochemistry
Date 2003 Jul 31
PMID 12888526
Citations 6
Authors
Affiliations
Soon will be listed here.
Abstract

To elucidate the contribution of LINE-like retrotransposon Zepp elements to the formation and maintenance of chromosomal telomeres, newly formed minichromosomes in irradiated Chlorella vulgaris cells were isolated and structurally characterized. A minichromosome (miniV4) of approximately 700 kb in size contained a Zepp cluster taking the place of the telomeric repeats on one terminus, whereas the other end of this chromosome consisted of canonical telomeric repeats. The Zepp copies in this cluster were in a tandem array with their poly(A) tails towards the centromere. Another minichromosome Y32 ( approximately 400 kb in size) was shown to have several copies of Zepp elements on both termini. On the right arm terminus, two copies of Zepp were found in a tandem array with poly(A) tracts facing towards the chromosomal end. The poly(A) tail and the 3'-end of approximately 400 bp of the distal copy were replaced by the telomeric repeats. On the 5'-side of the proximal copy was another Zepp element in the reverse orientation. These newly formed telomeric structures are very similar to those previously found in the left arm of chromosome I and the terminus of an unidentified chromosome and support the model of Zepp-mediated restoration and maintenance of Chlorella telomeres.

Citing Articles

On the origin of the eukaryotic chromosome: the role of noncanonical DNA structures in telomere evolution.

Garavis M, Gonzalez C, Villasante A Genome Biol Evol. 2013; 5(6):1142-50.

PMID: 23699225 PMC: 3698924. DOI: 10.1093/gbe/evt079.


The genome of the polar eukaryotic microalga Coccomyxa subellipsoidea reveals traits of cold adaptation.

Blanc G, Agarkova I, Grimwood J, Kuo A, Brueggeman A, Dunigan D Genome Biol. 2012; 13(5):R39.

PMID: 22630137 PMC: 3446292. DOI: 10.1186/gb-2012-13-5-r39.


Transcription and activation under environmental stress of the complex telomeric repeats of Chironomus thummi.

Martinez-Guitarte J, Diez J, Morcillo G Chromosome Res. 2008; 16(8):1085-96.

PMID: 18956244 DOI: 10.1007/s10577-008-1260-4.


Drosophila telomeric retrotransposons derived from an ancestral element that was recruited to replace telomerase.

Villasante A, Abad J, Planello R, Mendez-Lago M, Celniker S, de Pablos B Genome Res. 2007; 17(12):1909-18.

PMID: 17989257 PMC: 2099598. DOI: 10.1101/gr.6365107.


Centromeres were derived from telomeres during the evolution of the eukaryotic chromosome.

Villasante A, Abad J, Mendez-Lago M Proc Natl Acad Sci U S A. 2007; 104(25):10542-7.

PMID: 17557836 PMC: 1965549. DOI: 10.1073/pnas.0703808104.


References
1.
Okazaki S, Ishikawa H, Fujiwara H . Structural analysis of TRAS1, a novel family of telomeric repeat-associated retrotransposons in the silkworm, Bombyx mori. Mol Cell Biol. 1995; 15(8):4545-52. PMC: 230694. DOI: 10.1128/MCB.15.8.4545. View

2.
Mason J, Biessmann H . The unusual telomeres of Drosophila. Trends Genet. 1995; 11(2):58-62. DOI: 10.1016/s0168-9525(00)88998-2. View

3.
Schmidt T . LINEs, SINEs and repetitive DNA: non-LTR retrotransposons in plant genomes. Plant Mol Biol. 1999; 40(6):903-10. DOI: 10.1023/a:1006212929794. View

4.
Arkhipova I, Morrison H . Three retrotransposon families in the genome of Giardia lamblia: two telomeric, one dead. Proc Natl Acad Sci U S A. 2001; 98(25):14497-502. PMC: 64710. DOI: 10.1073/pnas.231494798. View

5.
Higashiyama T, Maki S, Yamada T . Molecular organization of Chlorella vulgaris chromosome I: presence of telomeric repeats that are conserved in higher plants. Mol Gen Genet. 1995; 246(1):29-36. DOI: 10.1007/BF00290130. View