TsDAF-21/Hsp90 is expressed in all examined stages of Trichinella spiralis.

Trichinella is an important parasitic nematode of animals worldwide. Heat shock proteins are ubiquitous in nature and allow organisms to quickly respond to environmental stress. A portion of the Tsdaf-21 gene, a Caenorhabditis elegans daf-21 homologue encoding heat-shock protein 90 (Hsp90) was cloned from Trichinella spiralis. The partial nucleotide sequence resided near the 5'-end of the gene and encoded a polypeptide of 254 amino acid residues harboring a HATPase-c superfamily domain and Hsp90 protein domain. Phylogenetic analysis revealed that Tsdaf-21 is highly conserved and formed a monophyletic clade with other nematodes. The partial Tsdaf-21 transcript was subcloned and expressed for antibody production. Results using PCR primers specific for the Tsdaf-21 transcript, and mouse polyclonal antisera specific for the recombinant protein showed that both the RNA transcript and the corresponding protein were ubiquitously and consistently expressed in newborn larvae, muscle larvae and both male and female adult worms in the absence of any external stress or stimulation.