Influence of dietary yeasts on Drosophila melanogaster life‐history traits

Abstract

An organism's fitness is highly dependent on resource quality. The diet of saprobiotic organisms often comprises a variety of microorganisms. Saprophagous Drosophila melanogaster Meigen (Diptera: Drosophilidae) is known to feed on various yeast species, both as larva and adult. The yeasts encountered by the insects may differ in composition and quality, and thus in their influence on larval and adult performance. Our study explores life-history consequences of larval diet on selected larval and adult traits, as well as larval and adult food choice and egg-laying behaviour. The chosen yeast species could be shown to influence several life-history traits of D. melanogaster, such as survival, development time, and adult body weight. Additionally, the amount of yeast biomass initially fed to the larvae significantly influenced development time and adult body weight, whereby the effect depended on the yeast species offered. There were also yeast-specific influences on the measured fitness traits when larvae were reared at different densities. Larvae exhibited a preference for those yeast species that had shown to favour most of the measured life-history traits. Adults, on the other hand, exhibited a different preference. Contrary to our expectation based on the preference-performance hypothesis, female adult flies did not prefer to lay their eggs on substrates inoculated with yeast species that had been shown to favourably influence larval development time. Possible reasons for this seemingly 'bad mother'-behaviour are being discussed.

Yeast Communities of Diverse Drosophila Species: Comparison of Two Symbiont Groups in the Same Hosts

“…Finally, since bacteria and fungi are recognized and cleared by semi-independent innate immunity pathways (42), a more nuanced control of the two symbiont groups is also possible. As both bacteria and yeasts can have significant effects on fly physiology and fitness (2,70,76), the host could be under selection to maintain only the most beneficial symbionts for that particular diet or location.…”

“…Only the 2,466 reads that were assigned with 100% confidence to the phylum Ascomycota were included in the final analysis. We chose to focus on the Ascomycota because previous studies had identified members of the phylum as important to Drosophila survival and fitness (2,4). The non-Ascomycota reads included 424 from the phylum Basidiomycota (see Data Set S4 in the supplemental material).…”

“…Different species of yeasts have different effects on Drosophila melanogaster survival and development time (2). Drosophila larvae show behavioral preferences for different yeast species, and in at least some cases, the preferred yeast species confers maximum fitness benefits on the host (13,47).…”

The ecology of insect–yeast relationships and its relevance to human industry

“…To date, the main model system in which yeasts have come to be understood as food sources is that of fruit flies, a system that might be highly derived. For D. melanogaster, the failure to find and eat yeasts means an early death [39], as these insects use the protein in yeasts for proper immunity and development [99,100].…”

Proteus mirabilis interkingdom swarming signals attract blow flies

“…For example, recent work has shown that some Drosophila strains will prefer to lay eggs only on food with yeast on it, whereas others will only lay eggs in substrates where they are absent (Miller et al, 2011). They also prefer oviposition substrates/foods inoculated with certain yeast strains (Vacek et al, 1985;Barker, 1992;Anagnostou et al, 2010), establishing a clear microbial connection to such behaviors in Drosophila. Microbial influences in Drosophila are not limited to yeast (the major protein source for fruit flies).…”