BMC Genomics 2009, 10:58 http://www.biomedcentral.com/1471-2164/10/58 FTeigmuproer6al expression patterns of cross-hybridizing P. sojae probesets Temporal expression patterns of cross-hybridizing P. sojae probesets. We identified 134 P. sojae probesets that cross-hybridized to H. glycines probes. These probesets were grouped into eight expression clusters. The average expression pattern of each cluster is represented by a bold line. even if there were plant material left after our nematode isolations, the amounts would be so minute that repeat- edly strong signals at about the same level and same developmental stage of the nematode in the different experiments performed by us are highly unlikely. Even more compellingly, we harvested H. glycines eggs in a very pure state and infective J2 stages from hatch chambers, a plant-free environment. Both stages show strong expres- sion signals for many soybean probesets. Since our BLAST searches described in Results ruled out the possibility of falsely annotated nematode sequences in P. sojae or soy- bean cDNA libraries, we believe that the strong expression Page 11 of 17 (page number not for citation purposes)