The grapevine (Vitis vinifera) is a widely cultivated crop that has been subjected to intensive breeding since the Neolithic period (from ~10,500 to ~6,000 years ago). The domestication of grapevine has undergone a selection for traits important for its cultivation and usage.
The recent publication of the complete grapevine genome has opened the possibility for an in-depth analysis of its content. This sequencing has shown that genes constitute only a very small proportion of complex genomes, with repetitive sequences and (in particular) mobile genetic elements or transposons making up a much larger part. Although transposition is a highly mutagenic event and genomes have developed very efficient mechanisms to control it, transposons have played a major role in the evolution of complex genomes.
A new study conducted by researchers at the CRAG (CSIC-IRTA-UAB) in Barcelona (Spain) in collaboration with the University of Natural Resources and Applied Life Sciences in Vienna (Austria), published in the online, open-access journal PLoS ONE, September 3, presents a genome-wide characterization of grapevine transposons. This work shows that transposons have captured and amplified gene sequences in grapevines, which could have had an impact on gene evolution and their regulation.
Conversely, some transposons have been "domesticated," losing their ability to transpose and probably fulfilling cellular roles as conventional genes do. Moreover, the research shows that grapevine transposons, some of which are probably still active, have played an important role in generating genetic diversity in this species.
The characterization of grapevine transposons will help to understand how the high genetic diversity of this species has been arisen and may be useful for the development of new molecular markers for the marker-assisted selection of new commercial varieties.
Source: Public Library of Science