TreeBASE Search-Trees for study 14254

@ARTICLE{TreeBASE2Ref22036, author = {Talima Pearson and Heidie M Hornstra and Jason W Sahl and Sarah Schaack and James M Schupp and Stephen M Beckstrom-Sternberg and Matthew W O'Neil and Rachael A Priestley and Mia D Champion and James S Beckstrom-Sternberg and Gilbert J Kersh and James E Samuel and Robert F Massung and Paul Keim}, title = {When Outgroups Fail; Phylogenomics of Rooting the Emerging Pathogen, Coxiella burnetii}, year = {2013}, keywords = {}, doi = {}, url = {http://}, pmid = {}, journal = {Systematic Biology}, volume = {}, number = {}, pages = {}, abstract = {Rooting phylogenies is critical for understanding evolution, yet the importance, intricacies and difficulties of rooting are often overlooked. For rooting, polymorphic characters among the group of interest (ingroup) must be compared to those of a relative (outgroup) that diverged before the last common ancestor (LCA) of the ingroup. Problems arise if an outgroup does not exist, is unknown, or is so distant that few characters are shared, in which case duplicated genes originating before the LCA can be used as proxy outgroups to root diverse phylogenies. Here, we describe a genome-wide expansion of this technique that can be used to solve problems at the other end of the evolutionary scale: where ingroup individuals are all very closely related to each other, but the next closest relative is very distant. We used shared orthologous single nucleotide polymorphisms (SNPs) from ten whole genome sequences of Coxiella burnetii, the causative agent of Q fever in humans, to create a robust, but unrooted phylogeny. To maximize the number of characters informative about the rooting, we searched entire genomes for polymorphic duplicated regions where orthologs of each paralog could be identified so that the paralogs could be used to root the tree. . Recent radiations, such as those of emerging pathogens, often pose rooting challenges due to a lack of ingroup variation and large genomic differences with known outgroups. Using a phylogenomic approach, we created a robust, rooted phylogeny for C. burnetii.} }