Elsevier

Genomics

Volume 46, Issue 1, 15 November 1997, Pages 51-60
Genomics

Regular Article
The Telomere-Associated DNA from Human Chromosome 20p Contains a Pseudotelomere Structure and Shares Sequences with the Subtelomeric Regions of 4q and 18p,☆☆

https://doi.org/10.1006/geno.1997.5007Get rights and content
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Abstract

The human chromosome 20p telomere has been cloned on a yeast artificial chromosome (YAC). The telomere-associated DNA contains an interstitial tract of (TTAGGG)ntelomeric repeats 60 kb in from the chromosome end. Frequent truncation of the YAC clone was observed due to resolution of the internal telomeric array into a telomere. The 20p internal telomeric repeat tract is flanked on its centromeric side by telomere-associated repeated sequences that have previously been found adjacent to terminal telomeric repeat arrays. The pseudotelomere structure of the 20p subtelomeric region is similar to the structure of some yeast subtelomeric regions where these sequences act as substrates for recombinational repair of chromosome ends that have lost their terminal telomeric repeat arrays. Sequences flanking the telomeric end of the internal (TTAGGG)nrepeat array on 20p are found adjacent to three other subtelomeric (TTAGGG)ntracts on 4q, 18p, and an unknown chromosome end, respectively. These shared sequences provide evidence of exchange between nonhomologous chromosomes in humans.

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Sequence data from this article have been deposited with the EMBL/GenBank Data Libraries under Accession Nos. AF020782 and AF020783.

☆☆

D. RickwoodB. D. Hanes, Eds.

1

Present address: Laboratory of Biochemistry and Metabolism, Building 10, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, MD 20892-1800.

2

To whom correspondence and reprint requests should be addressed. Telephone: (902) 494-7182. Fax: (902) 494-1355. E-mail: [email protected].