AGE-DEPENDENT ENZYME CHANGES IN DROSOPHILA-MELANOGASTER

1. 1. Marked age-dependent changes in four enzymes were found by assaying crude extracts of Drosophila melanogaster. 1.1. A. Hexose-P-isomerase from very old females lacked two of the five bands characteristic of young female extracts run on starch gels; the staining intensity increased for the older females and for older males. 1.2. B. Esterase from old males showed several additional electrophoretic bands which did not appear in assays of young males; in addition there was a large increase in staining intensity for male esterase and a lesser such increase for females. 1.3. C. G6PD activity-quantitatively determined-showed a significant increase and then a decrease as a function of age; peak activity of the male enzyme was for flies 25 days old, while this peak appeared at 49 days for females. 1.4. D. Alkaline phosphatase activity showed similar significant increases and decreases with age, with a plateau of activity occuring at 25 and 49 days for females, and a peak appearing with respect to males 49 days old. 2. 2. Survival curves for flies kept in shell vials were determined. They show later mortality for virgin females than for females who mate. Mated females had a slightly longer lifespan than mated or unmated males. 3. 3. These symptoms of aging Drosophila were established to form a basis looking for, then recognizing, genetic variants whose phenotype is an altered pattern of senescent change. Characterization of such aging mutants" could provide ways of understanding the process of senescence. © 1969."