Trans-generational effect of protein restricted diet on adult body and wing size of Drosophila melanogaster

Protein restriction (PR) has established feasible trade-offs in Drosophila
melanogaster to understand lifespan or aging in a nutritionally challenged
environment. However, the phenotypes of body size, weight and wing length
respond according to factors such as flies’ genotype, environmental
exposure, and parental diet and hence their understanding is essential.
Here, we demonstrate the effect of long-term PR diet on body size, weight,
normal & dry wing length of flies subjected to PR50 and PR70 (50%
and 70% protein content present in control food respectively) for 20
generations from pre-adult stage. We found that PR fed flies have lower
body weight, relative water content (in males), unaltered (PR50%) and
higher (PR70%) relative fat content in males, smaller normal and dry body
size as compared to control and generations 1 and 2. Interestingly, wing
size and pupal size of PR flies are smaller and showed significant effects
of diet and generation. Thus, these traits are sex and generation
dependent along with an interaction of diet, which is capable of
modulating these results variably. Taken together, the trans-generational
effect of PR on fitness and fitness-related traits might be helpful to
understand the underpinning mechanisms of evolution and aging in fruit
flies D. melanogaster.