Analysis of the translational capacity of the male accessory gland during aging in Acheta domesticus

Abstract

The protein synthesizing capacity of the male cricket accessory gland was inspected for changes associated with aging by analysis of organs from young (2 weeks post-imaginal molt), middle-aged (4 and 6 weeks) and senescent (8 weeks) animals. Total RNA content and the percentage of ribosomes in polysomes show an increase up to 4 weeks and then a steady decline. The rates of protein synthesis by young and old glands incubated in vitro were comparable, although the old glands were significantly less efficient in precursor uptake and therefore showed lower incorporation levels. The overall picture appears to be one of a steady but unspectacular decline in protein synthesizing capacity in aging animals. The quality of the secretory proteins formed by young and old glands was inspected by SDS-polyacrylamide gel electrophoresis and by isoelectric focusing, using both wide and narrow pH-range gels. While some differences in the banding patterns of isoelectric focusing gels were detected, they were eliminated by the inclusion of Triton X-100 in the gels. No other evidence for age-associated qualitative or quantitative changes was detected, strongly suggesting that proteins from young and old glands are identical.