Plant Phylogenomics: Defining Synergies Between Plant Systematics and Genome Biology
Jansen, Robert K. .
Comparative Chloroplast Phylogenomics: Implications for Phylogeny and Genome Evolution in Angiosperms.
Currently there are 100 completely sequenced plastid genomes available on GenBank with over 60 of these from angiosperms. The genomic data has provided a wealth of new data for resolving phylogenetic relationships among the major clades of angiosperms and for improving our understanding of evolution of these genomes. Phylogenetic analyses of a data set that includes 81 genes for 64 angiosperm genomes provides excellent resolution and support for resolving relationships among the major clades of angiosperms. This includes: confirmation that Amborella represents the earliest diverging lineage of angiosperms; resolution of the placement of Choranthales sister to magnoliids; the placement of the clade that includes Chloranthales/magnoliids sister to a large group that includes both eudicots and monocots; strong support for the monophyly of rosids, asterids; and resolution of relationships among some rosid clades whose position has been controversial. Comparisons of the organization among members of two angiosperm families, Campanulaceae and Geraniaceae, document extensive rearrangements, including large expansions/contractions of the inverted repeat and numerous gene order changes caused by inversions and loss/duplication of genes. These genomic rearrangements are associated with dispersed repeats, suggesting that they may have played an important role in genomic rearrangements. Comparisons of rates of sequence evolution among protein-coding genes have identified extensive rate heterogeneity among lineages and genes. In Geraniaceae, the genes with accelerated substitution rates are ATPase, ribosomal protein, and RNA polymerase genes. The evolutionary implications of the extensive rearrangements and accelerated substitution rates will be discussed.
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Jansen Web site
Chloroplast Genome Database
1 - University of Texas Austin, Section of Integrative Biology, 1 University Station, A6700, Austin, Texas, 78712-7640, USA
Presentation Type: Symposium or Colloquium Presentation
Location: Stevens 2/Hilton
Date: Monday, July 9th, 2007
Time: 10:15 AM