Difference between revisions of "Tomato genome"

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(Further comparisons using CoGe: Lack of evidence for a solanum specific hexaploidy)
(Tomato genome published in Nature)
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# Issue: http://www.nature.com/nature/journal/v485/n7400/
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* Issue: http://www.nature.com/nature/journal/v485/n7400/
# Nature Commentary: http://www.nature.com/nature/journal/v485/n7400/full/485547a.html
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* Nature Commentary: http://www.nature.com/nature/journal/v485/n7400/full/485547a.html
# Nature Article: http://www.nature.com/nature/journal/v485/n7400/full/nature11119.html
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* Nature Article: http://www.nature.com/nature/journal/v485/n7400/full/nature11119.html
## '''The tomato genome sequence provides insights into fleshy fruit evolution'''
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** '''The tomato genome sequence provides insights into fleshy fruit evolution'''
  
 
=Solanum-specific paleohexaploidy (whole genome triplication)=
 
=Solanum-specific paleohexaploidy (whole genome triplication)=

Revision as of 09:10, 1 June 2012

Tomato genome published in Nature

Screen Shot 2012-06-01 at 7.40.54 AM.png

Solanum-specific paleohexaploidy (whole genome triplication)

From: tomato genome sequence provides insights into fleshy fruit evolution

"Comparison with the grape genome also reveals a more recent triplication in tomato and potato. Whereas few individual tomato/potato genes remain triplicated (Supplementary Tables 10 and 11), 73% of tomato gene models are in blocks that are orthologous to one grape region, collectively covering 84% of the grape gene space. Among these grape genomic regions, 22.5% have one orthologous region in tomato, 39.9% have two, and 21.6% have three, indicating that a whole-genome triplication occurred in the Solanum lineage, followed by widespread gene loss. This triplication, also evident in potato (Supplementary Fig. 11), is estimated at 71 (±19.4) Myr on the basis of the Ks of paralogous genes (Supplementary Fig. 10), and therefore predates the ~7.3 Myr tomato–potato divergence."

Further comparisons using CoGe: Lack of evidence for a solanum specific hexaploidy

Tomato versus potato

If tomato and potato share a common recent hexaploidy, there should be a strong 1:3 syntenic signal in the syntenic dotplot of these genomes. With Ks value calculations, we would expect to see a strong orthologous region and two out-paralogous regions of approximately equal ages. However, analysis of these genomes in SynMap reveals one strong orthologous region and one out-paralogous region, which supports a shared tetraploidy. Interestingly, there are a couple of regions that show two out-paralogous regions.

Tomato versus grape

If tomato has a lineage specific hexaploidy, comparison to the grape genome (which only has the eudicot paleohexaploidy)) should show a 1:3 syntenic depth of orthologous regions, and a might weaker signal for their shared eudicot paleohexaploidy. However, analysis of the syntenic dotplot of these genomes (with Ks coloration), shows a strong 1:2 syntenic mapping of orthologous regions.