Brain Vacuolization and Muscle Protein Aggregation as Potential Biomarkers of Aging in Drosophila. Atanu Duttaroy¹, Kristopher Bcekwith², Peter Kibanyi Kibanyi¹, Eva Polston Polston². 1) Dept Biol, Howard Univ, Washington, DC; 2) Department of Physiology and Biophysics, Howard University, Washington, DC.

   Vacuoles appear in the form of clear spaces in Drosophila brain as it ages. This progressive vacuolization event is presumably related to the loss of CNS neurons, so the appearance of vacuoles in the brain is used as a typical hallmark of neurodegeneration in Drosophila. In order to compare the extent of brain vacuolization and its relationship with the amount of neuronal loss during biological aging we selected three fly strains CantonS (wild type strain), Methuselah (long lived strain) and White1118, the latter of which shares identical genetic background with methuellah. H&E stained sections of the fly brains from different ages were obtained and quantitative morphometric measurement was performed to analyze vacuole numbers and volumes, as well as neuronal numbers. Our observation revealed that the number and volume of vacuoles formed in the brain is directly correlated with the biological age of the fly; as the age of the animal increased, the number and sizes of vacuoles also increased. Next, we asked if the amount of vacuolization is related to the loss of brain cells. Number of nuclei counted from the same brain sections showed a surprising result, in that the numbers of neuronal nuclei remained same across all ages in all three genotypes. Our results therefore indicate that progressive brain vacuolization in Drosophila is not related to neurodegeneration. Aging muscle in Drosophila shows progressive accumulation of protein aggregates characterized by increased ubiquitination causing impaired muscle function at older age. Same three Drosophila genotypes were chosen: CantonS (wild type), w1118 and methuselah, and polyubiquitination of muscle proteins were monitored in immuno-histological sections as a function of age with an anti-ubiquitin antibody as well as by Western analysis. Our data shows that muscle ubiquitination is simply an age associated event.