Defenses Against Transposable Elements
An article published in Nature- Host genome surveillance for retrotransposons by transposon-derived proteins and authored by Hugh P. Cam, Ken-ichi Noma, Hirotaka Ebina, Henry L. Levin and Shiv I. S. Grewal (December 19, 2007; doi:10.1038/nature06499) discusses transposable elements which constitute a significant percentage of eukaryotic genomes. Organisms have mechanisms that defend them against transposable elements and, as the paper mentions, they include RNA interference and chromatin modifications.
In a blog entry about endogenous retroviruses and common descent telic meme commented "Inconsistencies do exist with phylogenetic analyses and are often explained by ad hoc arguments without positive evidence." Analyses need not neglect the possibility that similar effects result from similar defense mechanisms.
The Nature article described a genomic surveillance mechanism found in Schizosaccharomyces pombe (yeast). Mechanisms like the one described help ensure the maintenance of genomic integrity. They also aid our understanding of genomic changes and the inheritance of transposable elements.
Labels: Transposable Elements