Complex effects of environment and Wolbachia infections on the life history of Drosophila melanogaster hosts

Abstract

Wolbachia bacteria are common endosymbionts of many arthropods found in gonads and various somatic tissues. They manipulate host reproduction to enhance their transmission and confer complex effects on fitness‐related traits. Some of these effects can serve to increase the survival and transmission efficiency of Wolbachia in the host population. The Wolbachia–Drosophila melanogaster system represents a powerful model to study the evolutionary dynamics of host–microbe interactions and infections. Over the past decades, there has been a replacement of the ancestral wMelCS Wolbachia variant by the more recent wMel variant in worldwide D. melanogaster populations, but the reasons remain unknown. To investigate how environmental change and genetic variation of the symbiont affect host developmental and adult life‐history traits, we compared effects of both Wolbachia variants and uninfected controls in wild‐caught D. melanogaster strains at three developmental temperatures. While Wolbachia did not influence any developmental life‐history traits, we found that both lifespan and fecundity of host females were increased without apparent fitness trade‐offs. Interestingly, wMelCS‐infected flies were more fecund than uninfected and wMel‐infected flies. By contrast, males infected with wMel died sooner, indicating sex‐specific effects of infection that are specific to the Wolbachia variant. Our study uncovered complex temperature‐specific effects of Wolbachia infections, which suggests that symbiont–host interactions in nature are strongly dependent on the genotypes of both partners and the thermal environment.

Wolbachia has subtle effects on thermal preference in highly inbred Drosophila melanogaster which vary with life stage and environmental conditions

“…In line with this hypothesis, it was shown that Wolbachia interferes with pheromone production in females during pupariation and affects female-to-male communication (Pontier et al, 2015). Additionally, two recent papers demonstrated the absence of Wolbachia effects on locomotion and fitness at juvenile stage of wild-caught D. nigrosparsa (Detcharoen et al, 2020) and D. melanogaster flies (Strunov et al, 2022). The absence of Wolbachia effects on host juvenile traits is challenged by a study, which reported stable abundance of Wolbachia transcripts at all stages of host development (Gutzwiller et al, 2015), although there was no data on translation of the transcripts.…”

Association between parasite microbiomes and caste development and colony structure in a social trematode

“…Here, we show that members of two different castes in a social trematode harbour distinct microbiomes, and we further propose that the microbiomes of individuals might play a role in caste development. There is mounting evidence that an individual's microbiome can shape its phenotype (Diaz Heijtz et al, 2011 ; Feldhaar, 2011 ; Leclair et al, 2016 ; Strunov et al, 2022 ; Takacs‐Vesbach et al, 2016 ). On evolutionary timescales, microbiomes may even allow rapid adaptation (Alberdi et al, 2016 ) as well as influence animal speciation (Miller et al, 2021 ).…”

“…There is growing evidence that an individual's microbiome, or the microbial community it harbours, can influence its development and eventual phenotype (Diaz Heijtz et al, 2011 ; Feldhaar, 2011 ). Among conspecific animals, distinct morphotypes or life history strategies are often associated with distinct endosymbiotic microbial communities (Leclair et al, 2016 ; Strunov et al, 2022 ; Takacs‐Vesbach et al, 2016 ). In social insects, members of different castes within the same colony often harbour different microbial symbionts (Kapheim et al, 2015 ; Koto et al, 2020 ; Poulsen et al, 2014 ), though whether the acquisition of a particular microbial community precedes or follows the developmental adoption of a particular caste remains unclear.…”

Infection by wMel Wolbachia alters female post-mating behaviors and physiology in the dengue vector mosquito Aedes aegypti

“…As wMel Wolbachia increases female lifespan in D. melanogaster 61 and in wMel transinfected Ae. albopictus 62 , we asked if Wolbachia infection alters Ae.…”