Evolution of diverse mechanisms for protecting chromosome ends by Drosophila TART telomere retrotransposons.

ABSTRACT: The retrotransposons HeT-A, TART, and TAHRE, which maintain Drosophila telomeres, transpose specifically onto chromosome ends to form long arrays that extend the chromosome and compensate for terminal loss. Because they transpose by target-primed reverse transcription, each element is oriented so that its 5' end serves as the extreme end of the chromosome until another element transposes to occupy the terminal position. Thus 5' sequences are at risk for terminal erosion while the element is at the chromosome end. Here we report that TART elements in Drosophila melanogaster and Drosophila virilis show species-specific innovations in promoter architecture that buffer loss of sequence exposed at chromosome ends. The two elements have evolved different ways to effect this protection. The D. vi

SUBMITTER: George JA 

PROVIDER: S-EPMC3000255 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature