Metabolic labelling of wild and laboratory subspecies of the trichostrongyle nematode Heligmosomoides polygyrus.

The immunological, biochemical and taxonomic relationship between wild and laboratory subspecies of Heligmosomoides polygyrus was studied by metabolically labelling parasite proteins with [35S]-methionine. Much variability, both in content and synthesis of proteins was observed between the two subspecies. Laboratory female worms had a higher protein content and incorporated more radioactive label into somatic proteins than their wild counterparts. Incorporation of radioactivity into excretory/secretory (ES) proteins, predicted to contain important antigens, demonstrates a major reduction in synthesis of proteins with molecular weights 66, 55, 43, 41, 40, 39, 37, 28 and 16 kDa by laboratory females. These differences in protein synthesis might explain the differing infectivities of the two subspecies when passaged in inbred laboratory (Mus musculus) and wild (Apodemus sylvaticus) mice.