Variation in erythrocyte enzyme activity among primate species

Significant differences between species in the mean level of enzyme activity, ranging from 50 to 400%, were detected during a study of 10 enzymes from erythrocytes of humans and five non-human primates. The activity differences were consistent with variation, between species, at the structural loci for specific enzymes rather than differences in mean cell age, hemoglobin content or other pleiotropic effects. For seven of the eight loci at which direct comparisons among the six species could be made, the number of species-specific activity differences was greater than the number of variants observed by electrophoresis. Thus not only do activity measurements detect previously "hidden" variation among species but they also provide information regarding genetic differences which may be of potential physiological and/or selective relevance.