Diversity, Localization, and Microenvironments of the Specific Bacterial Symbionts of Social Spiders (Stegodyphus dumicola)

Research output: Contribution to conferencePosterResearch

Animals live in close association with microbes affecting them in many ways. The social spiders Stegodyphus dumicola live in large communal nests inhabited by hundreds of individuals, they spend their entire life in the nest and cooperate in many aspects of life including reproduction, brood care and foraging. Sociality leads to decreased genetic diversity and social spiders are highly inbred with extremely low genetic variation across populations. Hereby social spiders offer a standardized genetic background for studying animal-microbe symbiosis making it possible to separate the host and symbiont contribution to phenotype. The goal of this study was to identify specific symbionts of social spiders, and to determine, where and under which physical-chemical conditions these are present in the spider body. Stegodyphus dumicola were sampled in Namibia, South-Western Africa. DNA was extracted from whole animals, and the microbiome analyzed by 16S rRNA gene amplicon sequencing. Putative symbionts were localized in 20 µm-thin cryo-sections by fluorescence in situ hybridization, and oxygen and pH was measured in whole animals and in dissected midguts with glass microsensors. The social spider microbiome showed low diversity and was dominated by a few spider-specific lineages related to the genera Borrelia, Mycoplasma, Diplorickettsia, and Chlamydia. These symbionts were detected in the entire, heavily branching gut system, which fills large parts of the abdomen and also extends into head and legs. Symbionts mostly colonized the gut epithelium, and especially the cloaca was heavily populated. The spider body and midgut microenvironment was peripherally (micro-)oxic, but the oxygen concentration decreased to depletion towards the radial gut center, where a 1000 µM-wide anoxic zone was present. Thus, the spiders provide multiple niches for microaerophilic to anaerobe symbionts. The pH was near neutral in the outer gut tissue and decreased to 6.6 in the anoxic radial center, indicating fermentation activity inside the gut
Original languageDanish
Publication year2019
Publication statusPublished - 2019
EventGordon Research Conference on Animal-Microbe Symbioses: Animal-Microbe Symbioses as Nested Ecosystems - Mount Snow , West Dover, United States
Duration: 16 Dec 201921 Dec 2019
Conference number: 3
https://www.grc.org/animal-microbe-symbioses-conference/2019/

Conference

ConferenceGordon Research Conference on Animal-Microbe Symbioses
Number3
LocationMount Snow
CountryUnited States
CityWest Dover
Period16/12/201921/12/2019
Internet address

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