2%. To visualize the location of differences at the entire genome level, we utilized the “show SNP marks” feature of Artemis for visualizing BAM alignments (Fig. 2). The figure shows the 1/3 of each genome immediately preceding the origin of replication, with SNPs in red. The data show that SNPs are distributed across the S3I-201 molecular weight genome and agree with Table 3. For example, pyrosequencing data for Florida and Florida-relapse strains closely resemble the genome data derived by Sanger-based sequencing. Furthermore,

comparison of Fig. 2 with Table 2 and Table 3 clearly reveals the more closely related strains to Florida, i.e. Florida-relapse and Virginia and the more distantly related strains Oklahoma, Washington-O and South Idaho. These relationships are also seen in both SNP numbers and in shared msp2 and msp3 pseudogenes. A similar SNP comparison of U.S. strains of A. marginale with A. marginale

subspecies centrale ( Fig. 3) shows widely distributed SNPs and many gaps between marginale and centrale where there are no aligning reads. The locations of these gaps were largely identical for all the U.S. A. marginale strains, indicating a more distant sequence relationship between all these strains and the A. marginale this website subspecies centrale strain. We next examined the conservation of proposed vaccine antigens from the pfam01617 family, or that have been identified by other strategies. These other strategies involved cross-linking of surface proteins on live organisms by bifunctional reagents, analysis of T-cell responses of immunized and protected animals and identification of components of the type 4 secretion system recognized by T cells [14], [15], [17], [18], [19] and [26]. The data identified several proteins in each class that were conserved among all 10 U.S. strains

of A. marginale ( Table 4). Interestingly, none were conserved with A. marginale subspecies centrale. This suggests that relying only on antigens shared between marginale and centrale may not be an optimal strategy for development of vaccines against U.S. strains and of A. marginale. Additionally, comparison of the newly sequenced strains with the previously sequenced strains showed multiple genes that are variable in one or more strains; however, no candidate antigen gene was defined as absent in all the newly sequenced strains. Some genes, such as omps2, 7, 8 and 15 were more frequently detected as absent, whereas others, such as omps10 and 14, were detected as absent in only three comparisons between different A. marginale strains. An example of detailed coverage graphs for omp4 (conserved in all strains) and omp15 (variable) genes is shown in Fig. 4. Although omp15 coverage graphs suggest variability of this gene in most strains, the variability is localized to the C-terminus when all strains are compared to Florida and to the central region of omp15 when compared to St. Maries.