Abstract
Protein restriction (PR) has established feasible trade-offs in Drosophila melanogaster to understand lifespan or ageing 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 and dry wing length of flies subjected to PR50 and PR70 (50% and 70% protein content present in control food, respectively) for 20 generations from the 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 when compared with control and generations 1 and 2. Interestingly, the wing size and pupal size of PR flies are smaller and showed significant effects on diet and generation. Thus, these traits are sex and generation dependent along with a diet interaction, 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 ageing in fruit flies D. melanogaster.
Highlights
Organisms vary in body size across species and within a particular species
The results show that PR50 and PR70 have significantly lower body weight at gen 20 when compared with their previous generations; while PR50 females at gen 20 have lower body weight than gen 2, but not gen 1
With Protein restriction (PR) and long-term restrictions, the adult body weight is lower. To assess whether this lower body weight is owing to the water content, we weighed the dry weight of the flies
Summary
Organisms vary in body size across species and within a particular species. The variations in the body composition can influence phenotypic traits like body size, body weight, etc., while these trait variations can be attributed to various environmental and genetic factors [1,2,3]. The environmental factors that can influence organismal body size and weight, including wing length (especially in insects) can be nutrition [4], temperature [5,6], crowding [4,7], latitudinal clines [8] and royalsocietypublishing.org/journal/rsos R. Weight and wing 2 length are certain parameters that ensure the overall fitness of organisms including fruit flies. Variations in these phenotypes can be used to understand the genotypic changes that are bound to occur [10]
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