Variable expression of isozymes in entomopathogenic nematodes following laboratory recycling

Cellulose acetate electrophoresis was used to determine the degree to which isozyme banding patterns differed among 4 strains of steinernematid nematodes that had been recycled or stored at 5, 10, 15, 20 and 25 degrees C: Steinernema feltiae Umea strain, S. carpocapsae A11 strain, S. riobravis [S. riobravae] TX strain and S. feltiae NF strain. In all 4 strains, isozyme banding patterns of malate dehydrogenase (MDH), mannose-6-phosphate isomerase (MPI) and phosphoglucomutase (PGM) were affected by recycling or storage temperatures. The NF and Umea strains of S. feltiae synthesized additional isozymes of MPI and MDH or PGM at cold temperatures, while S. carpocapsae A11 strain synthesized 3 isozymes of MDH at warm temperatures and an additional isozyme of PGM at cold temperatures. The implications of these findings are discussed in relation to temperature adaptation mechanisms involving synthesis of isozymes and the use of isozyme determinations in steinernematid taxonomy..