The genes from the Phytophthora genomes each contain between one and seven intact cadherin thorough EC domains, though we did not attempt to construct accurate gene models for the Phytophthora genes. None of the oomycete cadherins appear to have the catenin binding domain, nor do these genomes appear to encode a b catenin gene, so like in M. brevicollis, the b catenin initiated part of the classical metazoan cadherin pathway appears to be absent from oomycetes. In order to explore the evolution of these domains in the oomycetes, we performed a phylogenetic analysis. The first cadherin EC domain has been used to explore gene phylogeny among the cadher ins, and to facilitate comparison we used both neighbor joining and maximum likelihood to estimate a phyloge netic tree for these same sequences together with all of the intact cadherin domains from the P.

ultimum and Ph. infestans genomes. To generate a high quality protein sequence alignment for phylogeny esti mation, we used the manual alignment of Nollet et al. Inhibitors,Modulators,Libraries as a seed for alignment Inhibitors,Modulators,Libraries of other sequences using MAFFT. We found that all of the oomycete domains fall within a single clade. However, this clade is broad and also contains several cadherins from the choanoflagellate M. brevicollis, as well as some of the more divergent metazoan cadherins. In general, the branches in this clade are very long, making phylogenetic reconstruction Inhibitors,Modulators,Libraries somewhat unreliable. Nevertheless, most of the cadherin domains found in P. ultimum are reliably orthologous to domains in one or more Phytophthora species, suggesting descent from a common ancestor by speciation.

The most notable Inhibitors,Modulators,Libraries example is for the genes PITG 09983 and PYU1 T011030, in which a region spanning three consecutive EC repeats appears to have been inherited by both species from that common ancestor. These repeats are also apparently orthologous to repeats in both Ph. sojae and Ph. ramorum. The oomycete Inhibitors,Modulators,Libraries cad herins may have been initially obtained either vertically or horizontally. No cadherins have been found in genomes sequenced from other clades more closely related to either oomycetes or the metazoan choanoflagellates. This means that, if cadherins were present in the most recent common ancestor Tofacitinib alopecia of oomy cetes and metazoans, these genes must have been lost independently in all of these other diverging lineages. Given the data currently available, it is more probable that at least one horizontal cadherin gene transfer event occurred from a choanoflagellate or metazoan to an oomycete ancestor, prior to the divergence of Pythium from Phytophthora. The source of the metazoan DNA may have been a host of the ancestral oomycete, or pos sibly introduced by a virus.