Comparative transcriptional profile of the fish parasite Cryptocaryon irritans

摘要: Cryptocaryon irritans is an obligate ectoparasitic ciliate pathogen of marine fishes. It can infect most teleosts and cause heavy economic losses in aquaculture. There currently no effective method controlling this disease, little information available regarding the genes involved its development virulence. We aimed to investigate distinct features three major life-cycle stages C. terms gene transcription level, identify candidate vaccines/drug targets. established a reference transcriptome by RNA-seq. Three cDNA libraries using total poly(A)+ mRNA isolated from trophonts, tomonts, theronts was constructed sequenced, respectively. Clean reads were de novo assembled generated unigene. Annotation unigenes transcriptomic comparison performed. Totals 73.15, 62.23, 109.57 million clean trophont, tomont, theront libraries, After assembly, 49,104 obtained, including 9,253 with significant similarities proteins other ciliates. Transcriptomic comparisons revealed that 2,470 differentially expressed among stages, 2,011, 1,404, 1,797 significantly tomont/theront, tomont/trophont, theront/trophont pairwise comparisons, Based on results hierarchical clustering, all (DEGs) located five clusters. DEGs clusters 1 2 more highly tomonts than cluster 3 dominant tomont trophont whereas 4 5 included upregulated stage. In addition, Immobilization antigens (I-antigens) proteases have long been considered targets for vaccine potential drug parasites, present study, nine putative I-antigens transcripts 161 protease found irritans. concluded enriched cell division, increase number ensure parasite continuity. associated response stimuli, trophonts related nutrient accumulation growth. I-antigen our could contribute vaccines or targeted drugs. Together, study provide novel insights into physiological processes parasitic ciliate.