Drosophila development, physiology, behavior, and lifespan are influenced by altered dietary composition

Abstract

Diet profoundly influences the behavior of animals across many phyla. Despite this, most laboratories using model organisms, such as Drosophila, use multiple, different, commercial or custom-made media for rearing their animals. In addition to measuring growth, fecundity and longevity, we used several behavioral and physiological assays to determine if and how altering food media influence wild-type (Canton S) Drosophila melanogaster, at larval, pupal, and adult stages. Comparing 2 commonly used commercial food media we observed several key developmental and morphological differences. Third-instar larvae and pupae developmental timing, body weight and size, and even lifespan significantly differed between the 2 diets, and some of these differences persisted into adulthood. Diet was also found to produce significantly different thermal preference, locomotory capacity for geotaxis, feeding rates, and lower muscle response to hormonal stimulation. There were no differences, however, in adult thermal preferences, in the number or viability of eggs laid, or in olfactory learning and memory between the diets. We characterized the composition of the 2 diets and found particularly significant differences in cholesterol and (phospho)lipids between them. Notably, diacylglycerol (DAG) concentrations vary substantially between the 2 diets, and may contribute to key phenotypic differences, including lifespan. Overall, the data confirm that 2 different diets can profoundly influence the behavior, physiology, morphology and development of wild-type Drosophila, with greater behavioral and physiologic differences occurring during the larval stages.

Keywords: D. melanogaster; bioactive peptides; diet; geotaxis; learning; locomotion; memory; morphology; muscle; thermal preference.

Figure 1.

Diet-dependent changes in the average developmental times of: A. larvae, B. pupae, C. Female Adults, D. Male adults. Horizontal dotted lines represent the 50% development and survivorship values (A-C, N = 12 vial replicates per diet). 50% values in days (Formula 4–24 vs. Jazz-mix vs. Control): Third-instar – 223.6 ± 1.65 vs. *177.2 ± 2.9 vs. *170.6 ± 2.8. Pupae – 276.1 ± 2.2 vs. *237.9 ± 2.0 vs. *231.7 ± 2.3. Female adults – 47.1 ± 11.1 vs. *63.6 ± vs. 60.0 ± 12.6. Male adults – 29.1 ± 7.1 vs. 49.7 ± 12.3 vs. 50.4 ± 11.3. *indicates a significant effect of diet compared with Formula 4–24 (Mean ± SD, P < 0.05).

Figure 2.

(A) 10⁻⁶ M octopamine-induced changes in basal tonus (*P < 0.01, N = 10 per diet); (B) the force of maximal contraction (elicited by 300 mM KCl) for larvae reared on both diets (N = 10 per diet); and (C) respective crawling speeds (Mean ± SD, *P < 0.05, N = 10 per diet).

Figure 3.

(A) Thermotaxis of larval Drosophila melanogaster reared on 2 different commercially available media, tested on a thermal gradient. (B) Image of thermal gradient using a thermal camera. (C) Image of thermal gradient under ambient light. Larvae reared on Formula 4–24 had a significantly higher preferred temperature compared with those reared on the Jazz-mix (Mean ± SD; 17.32 ± 0.43°C and 15.99 ± 0.29°C; * P < 0.05; N = 20 per diet).

Figure 4.

(A) Larval Drosophila reared on the Formula 4–24 retreated significantly further than those reared on Jazz-mix when placed on the hot side (38°C) of a thermal gradient ranging from 22–38°C (Mean ± SD; P < 0.01, N = 54). (B) A greater percentage of larvae reared on Formula 4–24 retreated beyond the 50% or 30°C point than those reared on Jazz-mix (N = 54, *P < 0.01).

Figure 5.

A significantly greater percentage of adult Drosophila climbed (A) beyond the 50% point when reared on jazz mix than those reared on Formula 4–24 (Mean ± SD; *P < 0.01, N = 12 per diet). (B) Depicts the apparatus used to assess negative geotaxis.

Figure 6.

Thermal preference in adult Drosophila was not influenced by diet (Mean ± SD; P=0.25, Formula 4–24, N = 19; Jazz mix, N = 17).

Figure 7.

Learning and memory assay reveals that adult Drosophila melanogaster learn equally well irrespective of the diet they are reared upon (Mean ± SD; *P>0.05, N = 10).