Why peach and grape genomes are peachy!
When comparing plant genomes, it is important to understand the genomic evolutionary history of the genomes being studied. Plant genomes are relatively unique from other major groups of organisms in that their genomes undergo whole genome duplication events relatively frequently. Their evolutionary history is littered by these events, and understanding the number of shared and distinct whole genome duplication events in a plant lineage is necessary for understanding the large scale differences in genome structure observed between two plant genomes.
To the best of our knowledge, prior to the radiation of the eudicots there was a paleohexaploidy event. In other words, all eudicot genomes are derived from a common hexaploid anestor. Some of these linegaes has additional whole genome diplication events (e.g. Arbidopsis), while others have not. These genomes without subsequent whole genome duplication events since the paleohexaploidy are important to identify and place in the eudicot phylogeny as they are excellent comparator genomes for studying plant genomes with subsequent whole genome duplication events. Grape was the first genome in which the paleohexaploidy was detected. This event was easily discernible because its genome has not had a subsequent whole genome duplication event and it was easy to detect that each region of the grape genome was syntenic to two other intragenomic regions.
The syntenic dotplot shown here compare:
- grape to Arabidopsis thaliana