Reduced Diversity in the Bacteriome of the Phytophagous Mite Brevipalpus yothersi (Acari: Tenuipalpidae)

Abstract

Tenuipalpidae comprises mites that transmit viruses to agriculturally important plants. Several tenuipalpid species present parthenogenesis, and in Brevipalpus yothersi, the endosymbiont Cardinium has been associated with female-only colonies. It is unclear what the bacterial composition of B. yothersi is, and how common Cardinium is in those microbiomes. We performed a comparative analysis of the bacteriomes in three populations of B. yothersi and three additional Tetranychoidea species using sequences from V4-fragment of 16S DNA. The bacteriomes were dominated by Bacteroidetes (especially Cardinium) and Proteobacteria, showing a remarkably low alpha diversity. Cardinium was present in about 22% of all sequences; however, it was not present in R. indica and T. evansi. In B. yothersi, the proportion of Cardinium was higher in adults than eggs, suggesting that proliferation of the bacteria could be the result of selective pressures from the host. This hypothesis was further supported because colonies of B. yothersi from different populations showed different bacterial assemblages, and bacteriomes from different mite species showed similar abundances of Cardinium. A phylogenetic analysis of Cardinium revealed that not only specialization but horizontal transmission has been important for this symbiosis. Together, these results represent a glimpse into the evolution of the Tetranychoidea and Cardinium.

The Microbiota of a Mite Prey-predator System on Different Host Plants Are Characterized by Functional Redundancy and Dysbiosis

“…Sharing the luminal space of the gut by a multispecies microbiota that is frequently exposed to new bacteria obtained from the environment also facilitates the acquisition of new genes through exchange of genetic material, which can potentially lead to the development of phenotypes with diverse metabolic pro les [12]. The maintenance of diverse facultative symbionts in host populations is thought to hinge mainly on the balance of selection between the costs and bene ts of infection, and is subjected to different selection pressures, such as diet, environmental habitat conditions, host developmental stage, and social behavior [17][18][19][20][21].…”