In the recent database issue of NAR, there are two reports of transposable element (TE) databases. I already discussed one in an earlier post. That one is a database that includes Gypsy elements (non-LTR retroposons) and retroviruses and aims to be a database “devoted to the non-redundant analysis and evolutionary-based classification of mobile genetic elements.” Hopefully to develop into a database of all TE’s. The other paper, by Levy et al. (“TranspoGene and microTranspoGene: transposed elements influence on the transcriptome of seven vertebrates and invertebrates“)1, I’ll discus briefly here introduces a somewhat different database of transposable elements.
As the paper discusses, TE’s have been implicated in a large number of effects on the vertebrate genome: affecting expression and “contributing to genetic diversity, genomic expansion, genomic content and genomic rearrangements.” Whether these immense changes are the raison d’être for transposable elements or the byproduct of a parasitic DNA element, I’ll leave for discussion (though I would side with the latter), but they are unarguably major factors in genome evolution and don’t fit the definition of “junk DNA.” :D.