This detection inside the fish cells is not due to the physical disruption of S. parasitica. When the fish cells were treated with recombinant SpHtp1, translocation without the presence of the pathogen

is observed. These results suggest that S. parasitica may have a biotrophic stage in the infection process, which is similar to what has been found in biotrophic and hemibiotrophic plant pathogenic oomycetes. Consequently, it is conceivable that the pathogen has an early infection stage, whereby it does not kill the host cells, but instead, host cells are kept alive in order to enhance its own growth. It is interesting to note that the cells in which SpHtp1 has been translocated, in the presence of S. parasitica (Fig. 2), seem to be somewhat smaller than the surrounding fish cells. It could be that the cells are in fact not smaller, but that the focal plane is not showing the true size of the cells. selleck inhibitor Alternatively, Saprolegnia is absorbing nutrients from the cells, which results in smaller fish cells. At present, we do not know how many RxLR effectors or whether other RxLR-like effectors are produced

by S. parasitica during an infection. However, the completion of the genome sequence in the near future (at The Broad Institute with Nusbaum, van West, Haas, Russ, Dieguez-Uribeondo and Tyler) will enable a more in-depth analysis of the number of putative RxLR proteins produced by S. parasitica. R428 price Our work was supported by the BBSRC (I.d.B., K.L.M., A.J.P., S.W., C.J.S., P.v.W.), the University of Aberdeen (E.J.R., V.L.A., C.J.S.,

P.v.W.) and The Royal Society (P.v.W.). We would like to acknowledge the Broad Institute (Carsten Russ, Rays Jiang, Brian Haas and Chad Nusbaum), Brett Tyler (VBI) and P.v.W. for early release of draft supercontigs of the genome sequence of isolate CBS233.65, which helped us choose the best control gene for the Q-PCR experiments and helped resolve the promoter sequence of SpHtp1. I.d.B., K.L.M., A.J.P., E.J.R. and S.W. contributed equally to this work. Fig. S1. Alignment of the full sequences of a subset of oomycete RxLR effector proteins. Fig. S2. Alignment of the upstream region of SpHtp1 with the conserved motif in the oomycete core promoter sequence and genome sequence of SpHtp1. Fig. Chorioepithelioma S3. Alignment of SpHtp1 with elicitin-like precursor proteins obtained by blastp analysis of SpHtp1 against nonredundant protein database in NCBI. Fig. S4. Primer sequences used for quantitative real time RT-PCR and reference gene analysis. Fig. S5. SpHtp1 is detected during infection. Fig. S6. Biochemical characterization of SpHtp124-198(His)6. Fig. S7. Uptake of SpHtp1 in fibroblast cells of the rainbow trout cell-line RTG-2. Please note: Wiley-Blackwell is not responsible for the content or functionality of any supporting materials supplied by the authors. Any queries (other than missing material) should be directed to the corresponding author for the article.