Bacterial Communities Differ among Drosophila melanogaster Populations and Affect Host Resistance against Parasitoids

Abstract

In Drosophila, diet is considered a prominent factor shaping the associated bacterial community. However, the host population background (e.g. genotype, geographical origin and founder effects) is a factor that may also exert a significant influence and is often overlooked. To test for population background effects, we characterized the bacterial communities in larvae of six genetically differentiated and geographically distant D. melanogaster lines collected from natural populations across Europe. The diet for these six lines had been identical for ca. 50 generations, thus any differences in the composition of the microbiome originates from the host populations. We also investigated whether induced shifts in the microbiome—in this case by controlled antibiotic administration—alters the hosts’ resistance to parasitism. Our data revealed a clear signature of population background on the diversity and composition of D. melanogaster microbiome that differed across lines, even after hosts had been maintained at the same diet and laboratory conditions for over 4 years. In particular, the number of bacterial OTUs per line ranged from 8 to 39 OTUs. Each line harboured 2 to 28 unique OTUs, and OTUs that were highly abundant in some lines were entirely missing in others. Moreover, we found that the response to antibiotic treatment differed among the lines and significantly altered the host resistance to the parasitoid Asobara tabida in one of the six lines. Wolbachia, a widespread intracellular endosymbiont associated with parasitoid resistance, was lacking in this line, suggesting that other components of the Drosophila microbiome caused a change in host resistance. Collectively, our results revealed that lines that originate from different population backgrounds show significant differences in the established Drosophila microbiome, outpacing the long-term effect of diet. Perturbations on these naturally assembled microbiomes to some degree influenced the hosts’ resistance against natural parasites.

Wolbachia affect behavior and possibly reproductive compatibility but not thermoresistance, fecundity, and morphology in a novel transinfected host, Drosophila nigrosparsa

“…We note that the recovering time of hosts after antibiotic treatment is important. Effects of antibiotics on the fly hosts were eliminated entirely within a few generations after treatment (Chaplinska, Gerritsma, Dini‐Andreote, Falcao Salles, & Wertheim, 2016; Fry, Palmer, & Rand, 2004). However, after five generations, the effects of antibiotics were not fully eliminated in D. simulans (Poinsot & Mercot, 1997).…”

Optimization of native biocontrol agents, with parasitoids of the invasive pest Drosophila suzukii as an example

“…In addition, an important biotic factor affecting the immune response is microbes. In Drosophila, the microbiome can affect immunity by increasing (Teixeira, Ferreira, & Ashburner, ; Xie, Butler, Sanchez, & Mateos, ) or decreasing resistance (Fytrou, Schofield, Kraaijeveld, & Hubbard, ), depending on microbial composition and/or host genetic background (Chaplinska, Gerritsma, Dini‐Andreote, Salles, & Wertheim, ). By experimental selection, it is possible to increase the ability of parasitoids to overcome the symbiont‐mediated resistance of the host (Rouchet & Vorburger, ).…”

Deleterious Interaction Between Honeybees (Apis mellifera) and its Microsporidian Intracellular Parasite Nosema ceranae Was Mitigated by Administrating Either Endogenous or Allochthonous Gut Microbiota Strains

“…Now, honey bee gastrointestinal microorganisms (i.e., gut microbiota) are known to play a critical role in regulating specific functions associated with metabolism and immune response (Evans and Lopez, 2004;Alberoni et al, 2016;Hyrsl et al, 2017). Microbial symbionts participate in various processes such as digestion of food (Koch and Schmid-Hempel, 2011), detoxification of harmful molecules, supply of essential nutrients, participation in the host's defense system (Lemaitre and Hoffmann, 2007;Hooper et al, 2012), and protection against pathogens and parasites (Evans and Lopez, 2004;Flint et al, 2012;Engel and Moran, 2013;Alberoni et al, 2016;Chaplinska et al, 2016). Although our understanding of mechanisms underlying interactions between the intestinal microbiota and parasites is still partial, it is widely acknowledged that the composition of the intestinal microbiota is a key factor in controlling infection dynamics (Berrilli et al, 2012).…”