The Arabidopsis genus

Arabidopsis thaliana is a model plant species and its molecular dissection has greatly contributed to our understanding of the systems preventing genome invasion by transposable elements (TE). Recent advances suggest that A. thaliana may be more efficient than its congener A. lyrata at controlling TE expression and proliferation. The comparative analysis of TE transcription in A. thaliana and A. lyrata, which differ by 40% in genome size, may help understand how silencing mechanisms contribute to the evolution of transposition rate, an important factor controlling genome size variation in plants and animals.