This Article Full Text Full Text (PDF) Supplemental Research Data All Versions of this Article: gr.5348806v1 16/10/1231    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by George, J. A. Articles by Pardue, M.-L. Search for Related Content PubMed PubMed Citation Articles by George, J. A. Articles by Pardue, M.-L. Social Bookmarking                   What's this?

Letter

Genomic organization of the Drosophila telomere retrotransposable elements

¹Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; ²Berkeley Drosophila Genome Project, Department of Genome Sciences, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA

The emerging sequence of the heterochromatic portion of the Drosophila melanogaster genome, with the most recent update of euchromatic sequence, gives the first genome-wide view of the chromosomal distribution of the telomeric retrotransposons, HeT-A, TART, and Tahre. As expected, these elements are entirely excluded from euchromatin, although sequence fragments of HeT-A and TART 3 untranslated regions are found in nontelomeric heterochromatin on the Y chromosome. The proximal ends of HeT-A/TART arrays appear to be a transition zone because only here do other transposable elements mix in the array. The sharp distinction between the distribution of telomeric elements and that of other transposable elements suggests that chromatin structure is important in telomere element localization. Measurements reported here show (1) D. melanogaster telomeres are very long, in the size range reported for inbred mouse strains (averaging 46 kb per chromosome end in Drosophila stock 2057). As in organisms with telomerase, their length varies depending on genotype. There is also slight under-replication in polytene nuclei. (2) Surprisingly, the relationship between the number of HeT-A and TART elements is not stochastic but is strongly correlated across stocks, supporting the idea that the two elements are interdependent. Although currently assembled portions of the HeT-A/TART arrays are from the most-proximal part of long arrays, ~61% of the total HeT-A sequence in these regions consists of intact, potentially active elements with little evidence of sequence decay, making it likely that the content of the telomere arrays turns over more extensively than has been thought.

E-mail mlpardue{at}mit.edu; fax (617) 253-8699.

Supplemental material is available online at http://www.genome.org.

Article published online before print. Article and publication date are at http://www.genome.org/cgi/doi/10.1101/gr.5348806.

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				R. C. Frydrychova, H. Biessmann, A. Y. Konev, M. D. Golubovsky, J. Johnson, T. K. Archer, and J. M. Mason Transcriptional Activity of the Telomeric Retrotransposon HeT-A in Drosophila melanogaster Is Stimulated as a Consequence of Subterminal Deficiencies at Homologous and Nonhomologous Telomeres Mol. Cell. Biol., July 1, 2007; 27(13): 4991 - 5001. [Abstract] [Full Text] [PDF]

				E. Casacuberta, F. A. Marin, and M.-L. Pardue Intracellular targeting of telomeric retrotransposon Gag proteins of distantly related Drosophila species PNAS, May 15, 2007; 104(20): 8391 - 8396. [Abstract] [Full Text] [PDF]