Insights into the Musa genome: Syntenic relationships to rice and between Musa species

• Main Authors: Althoff Ryan, Haas Brian J, Cheung Foo, Ronning Catherine M, Matsumoto Takashi, Kanamori Hiroyuki, Vilarinhos Alberto D, Garsmeur Olivier, D'Hont Angélique, Santos Candice MR, da Silva Felipe R, Leebens-Mack Jim, Blanc Guillaume, Ruiz Manuel, Ciampi Ana Y, Piffanelli Pietro, Lescot Magali, Arbogast Tammy, Hine Erin, Pappas Georgios J, Sasaki Takuji, Souza Manoel T, Miller Robert NG, Glaszmann Jean-Christophe, Town Christopher D
• Format: Article
• Language: English
• Published: BMC 2008-01-01
• Series: BMC Genomics
• Online Access: http://www.biomedcentral.com/1471-2164/9/58

<p>Abstract</p> <p>Background</p> <p><it>Musa </it>species (Zingiberaceae, Zingiberales) including bananas and plantains are collectively the fourth most important crop in developing countries. Knowledge concerning <it>Musa </it>genome structure and the origin of distinct cultivars has greatly increased over the last few years. Until now, however, no large-scale analyses of <it>Musa </it>genomic sequence have been conducted. This study compares genomic sequence in two <it>Musa </it>species with orthologous regions in the rice genome.</p> <p>Results</p> <p>We produced 1.4 Mb of <it>Musa </it>sequence from 13 BAC clones, annotated and analyzed them along with 4 previously sequenced BACs. The 443 predicted genes revealed that Zingiberales genes share GC content and distribution characteristics with eudicot and Poaceae genomes. Comparison with rice revealed microsynteny regions that have persisted since the divergence of the Commelinid orders Poales and Zingiberales at least 117 Mya. The previously hypothesized large-scale duplication event in the common ancestor of major cereal lineages within the Poaceae was verified. The divergence time distributions for <it>Musa</it>-Zingiber (Zingiberaceae, Zingiberales) orthologs and paralogs provide strong evidence for a large-scale duplication event in the <it>Musa </it>lineage after its divergence from the Zingiberaceae approximately 61 Mya. Comparisons of genomic regions from <it>M. acuminata </it>and <it>M. balbisiana </it>revealed highly conserved genome structure, and indicated that these genomes diverged circa 4.6 Mya.</p> <p>Conclusion</p> <p>These results point to the utility of comparative analyses between distantly-related monocot species such as rice and <it>Musa </it>for improving our understanding of monocot genome evolution. Sequencing the genome of <it>M. acuminata </it>would provide a strong foundation for comparative genomics in the monocots. In addition a genome sequence would aid genomic and genetic analyses of cultivated <it>Musa </it>polyploid genotypes in research aimed at localizing and cloning genes controlling important agronomic traits for breeding purposes.</p>