ed peptides of C. oncophora and 73% of those of O. ostertagi were found in at least one other nematode spe cies. Approximately half of these homologues were common to sequences in all nematodes examined. Strongylids had the largest subset of group specific homologues, while non strongylid parasite species had the fewest. Peptides predicted to be species specific were significantly shorter in length, on average, than peptides with matches in other species. This explains in part, the perceived sequence specificity in lieu of finding homologs as reported previously. Transcript profiles throughout the C. oncophora and O. ostertagi life cycle stages On average, 35% of the transcripts of a given stage are constitutively expressed in that specie, and this was true for both species. In C.

oncophora, 21% are found in all stages, whereas 24% are found in all stages of O. ostertagi. The KEGG pathways analysis suggests that the majority of these transcripts are involved in genetic information processing and in particular, transcription and translation, Dacomitinib the InterPro domains encoded by these transcripts confirm their associations with these functions. One of the most prevalent domains in constitutively expressed transcripts in both species is ubiquitin associated transla tion elongation factor. While some of the peptides encoded by constitutively expressed transcripts may not contain identifiable domains, most of them exhibit homology with other proteins.

The majority of these peptides had homologs in at least one specie from the three phylogenetic databases to which they were compared, whereas 79% and 75% have homologs in all three databases suggesting that constitutively expressed transcripts are involved in core cellular processes. As expected, peptides in C. oncophora and O. ostertagi had higher numbers of homologs among the Strongylida parasites than any other group, the fewest number were shared with the non Strongylida nematodes. The number of transcripts expressed in only one stage was small. In general, transcripts expressed in the later stages i. e. adult, had a high number of homologs in other species, whereas those expressed in the earlier stages i. e. egg, had fewer. The parasitic stages in cluding the L3sh exhibited a higher number of homologs in the strongylid parasites than in the other two groups of species, whereas more of the transcripts expressed in the free living stages showed similarity with organisms in the two non Strongylida groups than with those in the Strongylida group with the exception of the L3sh.

Comparing stage specific transcript expression within species revealed that the majority of transcripts expressed in each stage are not differentially expressed, 20% of transcripts in both species are up regulated in any given stage whereas 26% are down regulated. Comparative values for up and down regulated transcripts are shown in Figure 2C and 2D. On average 74% and 68% of up regulated transcripts have homologs in at least one nemat