Elimination of foreign DNA during somatic differentiation in Tetrahymena thermophila shows position effect and is dosage dependent.

ABSTRACT: In the ciliate Tetrahymena thermophila, approximately 15% of the germ line micronuclear DNA sequences are eliminated during formation of the somatic macronucleus. The vast majority of the internal eliminated sequences (IESs) are repeated in the micronuclear genome, and several of them resemble transposable elements. Thus, it has been suggested that DNA elimination evolved as a means for removing invading DNAs. In the present study, bacterial neo genes introduced into the germ line micronuclei were eliminated from the somatic genome. The efficiency of elimination from two different loci increased dramatically with the copy number of the neo genes in the micronuclei. The timing of neo elimination is similar to that of endogenous IESs, and they both produce bidirectional transcripts of the el

SUBMITTER: Liu Y 

PROVIDER: S-EPMC549336 | biostudies-literature | 2005 Feb

REPOSITORIES: biostudies-literature