Polymorphic and sex-limited phosphoglucomutase in Parastrongylus cantonensis (Nematoda: Angiostrongylidae).

Phosphoglucomutase was studied by polyacrylamide gel electrophoresis in the Thailand and Hawaii isolates of Parastrongylus cantonensis (also known as Angiostrongylus cantonensis). Two loci were present. The faster-moving locus (PGM-1) was polymorphic in the Hawaii isolate, represented by two alleles - the faster-moving, less common Pgm-1A and the slower-moving, more common Pgm-1B . It was monomorphic for the faster-moving allele Pgm-1A in the Thailand isolate. The slower-moving locus (PGM-2) was invariant, with a single band of enzyme activity, in the female worms of both the Thailand and Hawaii isolates. There was no detectable enzyme activity at this PGM-2 locus in the male worms of both isolates. The non-expression or 'null' PGM-2 phenotype in the male worms was presumed to be sex- limited. The present findings differ significantly in several aspects (polymorphic locus, proportion of polymorphic loci, heterozygosity, deviations from Hardy-Weinberg expectations, sex-limited expression) from the Japan isolate of P. cantonensis reported in the literature.