A comparison of the surface and secertions ofTrichinella pseudospiralisandT. spiralis

Abstract

SUMMARYIntact, viable adults, infective and newborn larvae ofTrichinella pseudospiraliswere surface labelled with125I by the chloramine T method and labelled proteins were compared with those obtained from equivalent stages ofT. spiralis. Electron-microscope autoradiography determined that labelled proteins were restricted to the cuticle for all stages of both isolates. Comparative polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate (SDS–PAGE), using thin gradient gel slabs, of proteins obtained from each stage, demonstrated that the profile of surface-labelled proteins ofT. pseudospiraliswere restricted in number, stage specific, and similar to equivalent proteins ofT. spiralisboth in size and in their organization into aggregates. The stage-specific profiles of surface-labelled proteins derived from newborn larvae were indistinguishable, but differences were noted between adults and infective larvae of the two isolates. These differences in protein structure were confirmed by two dimensional mapping of tryptic peptides. Stage-specific profiles were also obtained when [35S]methionine biosynthetically labelled secretions of the 3 stages ofT. pseudospiraliswere compared by SDS–PAGE. Comparison of the profiles obtained with secretions for respective stages ofT. spiralisagain failed to distinguish newborn larvae, but adults and infective larvae ofT. spiralisandT. pseudospiralisdisplayed a mixture of common and species-specific proteins. These findings are discussed in relation to the different pathology associated with infection with two isolates.