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

Abstract

<jats:title>Abstract</jats:title><jats:p><jats:italic>Wolbachia</jats:italic>, intracellular endosymbionts, are estimated to infect about half of all arthropod species. These bacteria manipulate their hosts in various ways for their maximum benefits. The rising global temperature may accelerate species migration and, thus, horizontal transfer of <jats:italic>Wolbachia</jats:italic> may occur across species previously not in contact. We transinfected and then cured the alpine fly <jats:italic>Drosophila nigrosparsa</jats:italic> with <jats:italic>Wolbachia</jats:italic> strain <jats:italic>w</jats:italic>Mel to study its effects on this species. We found low <jats:italic>Wolbachia</jats:italic> titer, possibly cytoplasmic incompatibility, and an increase in locomotion of both infected larvae and adults compared with cured ones. However, no change in fecundity, no impact on heat and cold tolerance, and no change in wing morphology were observed. Although <jats:italic>Wolbachia</jats:italic> increased locomotor activities in this species, we conclude that <jats:italic>D. nigrosparsa</jats:italic> may not benefit from the infection. Still, <jats:italic>D. nigrosparsa</jats:italic> can serve as a host for <jats:italic>Wolbachia</jats:italic> because vertical transmission is possible but may not be as high as in the native host of <jats:italic>w</jats:italic>Mel, <jats:italic>Drosophila melanogaster</jats:italic>.</jats:p>

Differential gene expression inDrosophila melanogasterandD. nigrosparsainfected with the sameWolbachiastrain

“…However, the mechanisms behind these interactions are not clear. Additionally, failure to transinfect Wolbachia strains from their native hosts to other species has been shown in many species, for example, between related species of parasitic wasps in the genus Trichogramma (Huigens et al ., 2004) and from D. melanogaster to D. nigrosparsa (Detcharoen et al ., 2020).…”

“…As uninfected D. nigrosparsa (nu_0), individuals of isofemale line iso12 were used that had been established using a population at Kaserstattalm, Tyrol, Austria (47.13°N, 11.30°E) in 2010 (Arthofer et al ., 2015; Cicconardi et al ., 2017) and had been maintained in the laboratory for about 60 generations before the founding of line nu_0. w Mel-infection of D. nigrosparsa was achieved as described in (Detcharoen et al ., 2020). Briefly, cytoplasm of D. melanogaster containing Wolbachia w Mel was transinfected into embryos of D. nigrosparsa line nu_0, and three infected lines, ni_3, ni_6, and ni_8, were generated.…”

“…Wild populations of D. melanogaster are commonly infected with Wolbachia (Verspoor and Haddrill, 2011), while no wild population of D. nigrosparsa infected with Wolbachia has been found to date (M. Detcharoen, unpubl.). We recently transinfected the Wolbachia strain w Mel from D. melanogaster into D. nigrosparsa and studied several traits including Wolbachia density as well as host temperature tolerance, larval and adult locomotion, and cytoplasmic incompatibility (Detcharoen et al ., 2020). Our analysis of the new host-endosymbiont system of Drosophila nigrosparsa infected with Wolbachia w Mel revealed increased locomotion compared with flies tetracycline cured from their infection as well as hints of weak cytoplasmic incompatibility (Detcharoen et al ., 2020).…”

No influence of antibiotic on locomotion inDrosophila nigrosparsaafter recovery, but influence on microbiome, possibly mediating wing-morphology change

“…The aim of this study is to examine the effect of tetracycline on Drosophila nigrosparsa two generations after using tetracycline. Better knowing the long-term effects of tetracycline on D. nigrosparsa is needed for better interpreting published (Detcharoen et al , 2020) and future results, given that this species is in the focus of climate-change research (Kinzner et al , 2019). Thus, we ask if changes in the flies result from previous Wolbachia infection or previous tetracycline treatment.…”

“…For this purpose, non-infected D. nigrosparsa are treated with tetracycline and compared with a control group to investigate the sole effect of the antibiotic on the flies. The experiments examine the locomotion of larvae and adults as well as the wing morphology, which were included in a previous study examining the effects of Wolbachia on D. nigrosparsa (Detcharoen et al , 2020). The gut microbiome is characterized in this study, and in addition, gut-microbiome restoration is tested as a solution to reducing potential side effects of tetracycline on the microbiome more quickly than without using it.…”