Periodic Reporting for period 5 - SYMBeetle (Symbiont-assisted cuticle biosynthesis as a key innovation contributing to the evolutionary success of beetles)
Période du rapport: 2024-02-01 au 2024-05-31
While characterizing the microbial communities across several different beetle families, we discovered a novel intracellular symbiont that is widespread across at least six different insect orders and appears to be especially common in beetles (Wierz et al. 2024b). The symbiont shows high prevalence in beetle populations and infects multiple host tissues including the ovaries as well as eggs, indicating vertical transmission. Genomic analyses reveal that the symbiont has the potential to be pathogenic, but it may also provide nutritional supplements to the host. This newly described symbiont that we called “Symbiodolus” may provide excellent opportunities to study the molecular underpinnings of the transition from pathogenicity to mutualism.
Kiefer, J.S.T. Batsukh, S., Bauer, E., Hirota, B., Weiss, B., Wierz, J., Fukatsu, T., Kaltenpoth, M., Engl, T. (2021) Inhibition of a nutritional endosymbiont by glyphosate abolishes mutualistic benefit on cuticle synthesis in Oryzaephilus surinamensis. Communications Biology 4:554.
This study provides the first evidence that oral exposure to glyphosate can impact a bacteriome-localized symbiont of an insect, with detrimental effects on host fitness. As such, it reveals that xenobiotics can systemically penetrate an insects’ body and cause undesired side effects. Thus, if substantiated under ecologically relevant conditions, xenobiotics such as pesticides and herbicides may contribute to the currently observed decline in insect populations in nature.
Reis, F., Kirsch, R., Pauchet, Y., Bauer, E., Bilz, L.C. Fukomori, K., Fukatsu, T., Kölsch, G., Kaltenpoth, M. (2020) Bacterial symbionts support larval sap feeding and adult folivory in (semi-)aquatic reed beetles. Nature Communications 11: 2964.
In this study, we reconstructed the evolutionary history of the symbiosis in reed beetles (Chrysomelidae, Donaciinae) and uncovered two life-stage specific benefits provided by the symbionts, based on genomic data: While the larvae profit from the symbionts’ production of essential amino acids, the adults gain access to the carbon- and energy-rich plant cell wall components by the symbionts’ pectinases (Reis et al. 2020). In addition, phylogenetic analyses reveal that the symbiosis initially expanded the hosts’ ecological niche space, but later restricted its evolutionary potential, providing a rare example demonstrating the potential of symbionts to both broaden and confine a host’s ecological opportunities.