Biology subjects

Marten, S.-M.

Publications and source records attributed to Marten, S.-M..

4 recordsLinked to original sources

bioRxiv2024

Evaluating bacteriophage impact on gut microbiome composition in broad-nosed pipefish (Syngnathus typhle)

Bacteriophages play a crucial role in shaping microbial community dynamics in marine systems and have the potential to stimulate surges in pathogenic bacteria facilitating disease outbreaks. Notwithstanding, bacteriophages also serve as valuable biocontrol agents, underscoring their huge potential for aquaculture therapy treatments. Insights into the intricate tripartite interplay upon an infection with a virulent bacterium, its specific phages and the eukaryotic microbiome could improve our understanding of how bacteria-phage interactions behave in a natural microbial system. This investigation assessed the influence of a virulent Vibrio alginolyticus (K01M1) infection, in tandem with lytic ([fe]St2) and filamentous ([fe]K04M1) Vibrio-specific phages, on the broad-nosed pipefish (Syngnathus typhle) gut microbiome using 16S rRNA amplicon sequencing and non-intrusive gastric swabbing. Microbial communities and diversity metrics were not permanently impacted by Vibrio and phage introductions, while the different infection regimes shaped Vibrio-specific dynamics. In the filamentous phage and Vibrio-only treatments, V. alginolyticus abundances spiked 12 hours post-ingestion. In contrast, V. alginolyticus numbers in the lytic phage and control treatment were significantly reduced, suggesting phage activity and specific elimination of the introduced bacteria. Assisted by relative true-gut tissue samples, a newly implemented non-intrusive swabbing method was successful at discerning the activity of two contrasting phages and supports previous work that encourages the use of [fe]St2 in bacteriophage treatments. Identifying Vibrio-specific phages with similar positive characteristics could be beneficial for the aquaculture trade, which is currently heavily impacted by the antibiotic crisis.

microbiology↗

bioRxiv2024

Shaping tiny worlds: Paternal microbiota manipulation influences offspring microbial colonization and development in a sex role-reversed pipefish

Microbes are acquired through vertical and environmental horizontal transmission. Vertical transmission is directly linked to reproductive success and entails early transmission, facilitating coexistence of host and microbes over generations. The multiple potentially interacting routes of vertical transmission are challenging to be disentangled in conventional sex-role species, as they are mostly intermingled on the maternal side, i.e., through egg production, pregnancy, birth and postnatal care. The evolution of male pregnancy in syngnathids (pipefishes and seahorses) offers an opportunity to separate vertical microbial provisioning through the egg (maternal) from provisioning through pregnancy (paternal). We experimentally evaluated the existence and role of paternal microbiota provisioning through male pregnancy on offspring development and microbial colonization. Male pipefish were exposed to antibiotics, and subsequently recolonized with bacteria of paternal, maternal, and environmental origin (spike treatment). After pregnancy, the microbiome (16s rRNA) of developing offspring was repeatedly ribotyped. Paternal antibiotic and spike treatments influenced the microbial composition of the brood pouch and offspring microbiome development. Paternal spike treatment gave offspring a kickstart in life by reducing pregnancy duration and inducing offspring survival. Expanding on how distinct vertical microbial transmission routes shape offspring microbiome will foster our understanding of the holobiont function in health and disease.

evolutionary biology↗

bioRxiv2024

Parent-specific transgenerational immune priming enhances offspring defense - unless heat-stress negates it all

Trans-generational immune priming (TGIP) adjusts offspring immune responses based on parental immunological experiences - a form of trans-generational plasticity predicted to be adaptive when parent-offspring environmental conditions match. In contrast, mis-matches between environmental conditions negate those advantages, rendering TGIP costly when mismatched immunological offspring phenotypes are induced. Particularly maternal TGIP was thought to shape offspring immunological preparedness: mothers eggs contain more substance than sperm and, in viviparous species, pregnancy provides additional avenues for immune priming of developing offspring. The syngnathids (pipefishes and seahorses) unique male pregnancy provides an unusual perspective to the ecological relevance of TGIP in a system where egg production and pregnancy occur in different sexes. We simulated parental bacteria exposure in broad nosed pipefish, Syngnathus typhle, through vaccinations with heat-killed Vibrio aestuarianus before mating the fish to each other or control individuals. Resulting offspring were raised, and some exposed to V. aestuarianus, in a control or heat-stress environment, after which transcriptome and microbiome compositions were investigated. Transcriptomic TGIP effects were only observed in Vibrio-exposed offspring at control temperatures, arguing for low costs of TGIP in non-matching environments. Transcriptomic phenotypes elicited by maternal and paternal TGIP had only limited overlap and were not additive. Both transcriptomic responses were significantly associated to immune functions, and specifically the paternal response to the innate immune branch. TGIP of both parents reduced the relative abundance of the experimental Vibrio in exposed offspring, showcasing its ecological effectiveness. Despite its significance in matching biotic environments, no TGIP-associated phenotypes were observed for heat-treated offspring. Heat-spikes caused by climate change thus threaten TGIP benefits, potentially increasing susceptibility to emerging marine diseases. This highlights the urgent need to understand how animals will cope with climate-induced changes in microbial assemblages by illustrating the importance - and limits - of TGIP in mitigating the impacts of environmental stressors on offspring vulnerability.

evolutionary biology↗

bioRxiv2021

Lower Vibrio spp. abundances in Zostera marina leaf canopies suggest a novel ecosystem function for temperate seagrass beds

Seagrasses, a polyphyletic group of about 60 marine angiosperm species, are the foundation of diverse and functionally important marine habitats along sheltered sedimentary coasts. As a novel ecological function with high societal relevance, a role of the leaf canopy for reducing potentially harmful bacteria has recently been hypothesized. Accordingly, we tested whether or not the abundance of general bacteria and more specifically, those belonging to the genus Vibrio were reduced within temperate Zostera marina (eelgrass) meadows compared to adjacent sand flats and sampled 5 sites in the south-western Baltic Sea using SCUBA. Compared to non-vegetated area, we found an average reduction of 39% for all Vibrio and 63% for the potentially harmful V. vulnificus/cholerae subtype based on robust plate counting data on Vibrio selective agar. The underlying mechanism is currently elusive and clearly merits further study. Our results underline the critical importance of seagrasses in maintaining shallow water ecosystem functioning including water quality and provide further motivation for their protection and restoration.

ecology↗