Submitted to: Coccidiosis International Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 6, 2005
Publication Date: September 15, 2005
Citation: Miska, K.B., Lillehoj, H.S., Fetterer, R.H. 2005. The developmental expression of eimeria heat shock protein 90. Coccidiosis International Conference Proceedings, p. 163.
Heat shock protein 90 (Hsp90) represents one of the most abundant and evolutionarily conserved proteins. Because in most species studied Hsp90 was found to be essential for proper cell function, a study investigating Eimeria Hsp90 was initiated. The full-length Eimeria acervulina and Eimeria maxima Hsp90 cDNAs have been isolated and sequenced. From evolutionary analysis and sequence identity, it is likely that Eimeria Hsp90 sequences described so far encode the cytosolic versions of the protein. Although at the nucleotide and amino acid level Eimeria Hsp90 are highly similar, their expression profiles differ considerably. The E. acervulina Hsp90 transcripts are developmentally regulated, which little to no expression present in developing as well as fully sporulated oocysts. Analysis of Hsp90 protein in E. acervulina corroborates with RT-PCR data, where highest protein levels being expressed by sporozoites and merozoites, with little or no expression in oocysts. While E. tenella Hsp90 transcripts were present in every stage tested, the amounts of transcripts differed among stages. The mRNA expression profile was very similar to the protein expression, where the highest amounts of protein were expressed sporozoites and merozoites. We have also observed that E. tenella Hsp90 is not actively secreted by sporozoites or merozoites. At this time the significance of different Hsp90 expression profiles in the three Eimeria species is not known, however, it is obvious that the mechanisms of oocyst development at the molecular level may be quite different between Eimeria.