MALIC DEHYDROGENASE ISOENZYMATIC PATTERN IN LUNG-NEMATODE PARASITE SPECIES

The malic dehydrogenase (MDH) isoenzymatic pattern of Dictyocaulus viv iparus, Protostrongylus rufescens, and Slovakian and Spanish isolates of D. filaria was studied. The MDH isoenzymatic pattern in both isolat es of D. filaria was characterized by the presence of three phenotypes : (1) a single, slow anodic band; (2) a single, fast anodic band; and (3) a large spot matching its migration with bands 1 and 2. These thre e phenotypes may be explained as the existence of only one gene locus for the MDH in D. filaria. Allelic frequencies and the Hardy-Weinberg test were determined for Slovakian and Spanish isolates of D. filaria. This test indicated that the population was not in Hardy-Weinberg equ ilibrium. The MDH isoenzymatic pattern of D. viviparus displayed the s ame phenotypes 1 and 2 observed in D. filaria. Furthermore, the MDH is oenzymatic pattern of P. rufescens was characterized by the presence o f two bands with anodic and cathodic migration. The isoenzyme with ano dic migration appeared more intensively stained than did that with cat hodic migration. This last isoenzyme was not observed when the samples had been stored for 1 month.