Natural GMOs Part 196. Plants can frequently exchange genetic material through horizontal transfers

Widespread and frequent horizontal transfers of natural mobile DNA in plants

Vertical, transgenerational transmission of genetic material occurs through reproduction of living organisms. In addition to vertical inheritance, horizontal gene transfer between reproductively isolated species has recently been shown to be an important, if not dominant, mechanism in the evolution of prokaryotic genomes. In contrast, only a few horizontal transfer (HT) events have been characterized so far in eukaryotes and mainly concern transposable elements (TEs). Whether these are frequent and have a significant impact on genome evolution remains largely unknown. We performed a computational search for highly conserved LTR retrotransposons among 40 sequenced eukaryotic genomes representing the major plant families. We found that 26 genomes (65%) harbor at least one case of horizontal TE transfer (HTT). These transfers concern species as distantly related as palm and grapevine, tomato and bean, or poplar and peach. In total, we identified 32 cases of HTTs, which could translate into more than 2 million among the 13,551 monocot and dicot genera. Moreover, we show that these TEs have remained functional after their transfer, occasionally causing a transpositional burst. This suggests that plants can frequently exchange genetic material through horizontal transfers and that this mechanism may be important in TE-driven genome evolution.

Widespread and frequent horizontal transfers of transposable elements in plants

Moaine El Baidouri, Marie-Christine Carpentier, Richard Cooke, Dongying Gao, Eric Lasserre, Christel Llauro, Marie Mirouze, Nathalie Picault, Scott A. Jackson and Olivier Panaud
Published in Advance February 11, 2014, doi:10.1101/gr.164400.113
Genome Res. 2014. 24: 831-838
Full Paper @ Widespread and frequent horizontal transfers of transposable elements in plants:

See an earlier post in this series, Natural GMOs Part 123, for one example of how this DNA moves

A natural graft between a birch (left) and an oak (right).
Sexually incompatible species can exchange chloroplast genomes at graft sites.
(Credit: Image courtesy of Max Planck Institute of Molecular Plant Physiology)