Lusters suggesting that also these have five or more alleles. A

Lusters suggesting that also these have five or more alleles. A similar picture emerges from the limited analyses of S. vortens data (Table 2). The genome project of S. vortens reported large difficulties with genome assembly [15]. Total scaffold and contig lengths were 104 and 33 Mb, respectively, which is much larger than the previously estimated genome size of 16 Mb [44]. A probable cause of the problems is the presence of extensive allelic variation for a large part of the genome. Local gene duplications followed by divergence may also contribute to the high allelic numbers found in S. vortens and S. barkhanus. Interestingly, the S. vortens genes with theRoxstr -Lindquist et al. BMC Genomics 2010, 11:258 http://www.biomedcentral.com/1471-2164/11/Page 9 ofTable 2: SNPs observed in homologous regions in the S. vortens genome.Gene Enolase Ribosomal protein S2 Glutamate dehydrogenase HSP70 Pyruvate kinasea)length 563 508 N/Ab 517#GSSa 5 5 24#ESTa 9 >300 100 >#SNP 0 10 >40 >Covering at least 80 of the region. b) Not available; no glutamate dehydrogenase sequences were detected in the released S. vortens sequences.highest number of SNPs in our study have the largest number of GSSs (Table 2), circumstantially suggesting duplications of these genes. Comparative genome size estimates of S. barkhanus and S. salmonicida were performed to test whether the differences in allelic sequence variation were correlated with genome size variations (Figure 3 and Additional file 8).Divergent genome sizes of S. barkhanus and S. salmonicidaWe studied the genome size using flow cytometry analysis of S. barkhanus and S. salmonicida cells with fluorescently labelled DNA (Figure 3). The total amount of DNA in each cell was compared to the amount of DNA in G. intestinalis WB trophozoites, which has been estimated to have a haploid genome size of 12 Mb [48]. Exponentially growing Giardia trophozoites display two peaks with cells in the G1 and G2/M phases of the cell cycle with ploidies of 4N and 8N, respectively. The majority of cells can be found in the G2/M phase [18]. The G1 peak corresponds to a total genome size of 48 Mb (4 ?12 Mb) and the G2/M peak to a genome size of 96 Mb (8 ?12 Mb) (Figure 3A and 3C). S. barkhanus has two major peaks that correspond to total genome sizes of around 72 and 144 Mb (Figure 3B). This corresponds to a haploid genome size of 18 Mb, if a cycling of ploidy between 4N and 8N is assumed. The major peaks of S. salmonicida Nelfinavir (Mesylate) are very close to the peaks of G. intestinalis, suggesting a haploid genome size around 12 Mb for S. salmonicida (Figure 3CD). We also studied the genome size using PubMed ID:https://www.ncbi.nlm.nih.gov/pubmed/6833145 pulsed-field gel electrophoresis (PFGE). Unfortunately, the chromosomes were poorly separated in our PFGE experiments, preventing precise estimations of genome sizes using this method (Additional file 8). Nevertheless, our genome size determinations using flow cytometry show a large difference in haploid genome sizes between S. barkhanus and S. salmonicida. This suggests that genome sizes are dynamic within diplomonads and may differ considerably even between relatively closely related and morphological indistinguishable species.Conclusions We have performed a comparative study of S. barkhanus and S. salmonicida, as a part of our ongoing project on comparative genomics in diplomonads. Traits which distinguish these from other studied diplomonads were identified, such as the ability to incorporate selenocysteine into proteins. Our results also indica.