Biology subjects

Reitzel, A.

Publications and source records attributed to Reitzel, A..

6 recordsLinked to original sources

bioRxiv2024

De-novo Genome of the Edwardsiid anthozoan Edwardsia elegans

Cnidarians (sea anemones, corals, hydroids, and jellyfish) are a key outgroup for comparisons with bilaterial animals to trace the evolution of genomic complexity and diversity within the animal kingdom, as they separated from most other animals 100s of millions of years ago. Cnidarians have extensive diversity, yet the paucity of genomic resources limits our ability to compare genomic variation between cnidarian clades and species. Here we report the genome for Edwardsia elegans, a sea anemone in the most specious genus of the family Edwardsiidae, a phylogenetically important family of sea anemones that contains the model anemone Nematostella vectensis. The E. elegans genome is 396 Mb and predicted to encode approximately 49,000 proteins. We annotated large conservation of macrosynteny between E. elegans and other Edwardsiidae anemones as well as conservation of both microRNAs and ultra conserved noncoding elements previously reported in other cnidarians species. We also highlight microsyntenic variation of clustered developmental genes and ancient gene clusters that vary between species of sea anemones, despite previous research showing conservation between cnidarians and bilaterians. Overall, our analysis of the E. elegans genome highlights the importance of using multiple species to represent a taxonomic group for genomic comparisons, where genomic variation can be missed for large and diverse clades.

genomics↗

bioRxiv2021

Microbiota mediated plasticity promotes thermal adaptation in Nematostella vectensis

At the current rate of climate change, it is unlikely that multicellular organisms will be able to adapt to changing environmental conditions through genetic recombination and natural selection alo. Thus, it is critical to understand alternative mechanisms that allow organisms to cope with rapid environmental changes. Here, we used the sea anemone Nematostella vectensis as model to investigate the microbiota as putative source of rapid adaptation. Living in estuarine ecosystems, highly variable aquatic environments, N. vectensis has evolved the capability of surviving in a wide range of temperatures and salinities. In a long-term experiment, we acclimated polyps of Nematostella to low (15{degrees}C), medium (20{degrees}C) and high (25{degrees}C) temperatures, in order to test the impact of microbiota-mediated plasticity on animal acclimation. Using the same animal clonal line, propagated from a single polyp, allowed us to eliminate effects of the host genotype. Interestingly, the higher thermal tolerance of animals acclimated to high temperature, could be transferred to non-acclimated animals through microbiota transplantation. In addition, offspring survival was highest from mothers acclimated to high temperature, indicating the transmission of thermal resistance to the next generation. Microbial community analyses of the F1 generation revealed the transmission of the acclimated microbiota to the next generation. These results indicate that microbiota plasticity can contribute to animal thermal acclimation and its transmission to the next generation may represent a rapid mechanism for thermal adaptation.

evolutionary biology↗

bioRxiv2019

Shift in bacterial taxa precedes morphological plasticity in a larval echinoid

Morphological plasticity is an adaptive response to heterogenous environments when a fitness advantage is conferred. Larval sea urchins, for example, increase individual fitness in dilute feeding environments by elongating their feeding structure. Morphological plasticity for larval sea urchins is also coupled with significant shifts in the associated bacterial community, but whether this response occurs before, during, or following the expression of plasticity is unclear. Using the sea urchin Lytechinus variegatus, we define the temporal pattern of the associated bacterial community throughout the expression of morphological plasticity. From prefeeding through plasticity, we observed that L. variegatus larvae exhibit a four-stage successional pattern and the relatedness of the larval-associated bacterial community directly reflects morphological plasticity and does so prior to expression of the environmental-specific morphology. Based on the structure of the larval-associated bacterial communities, the expression of morphological plasticity correlates short-arm larvae deviating from the microbial trajectory of pre-plastic siblings. Taken together, these data suggest that a holobiont may exhibit shifts in the associated bacterial community corresponding with the environmental variation in absence or anticipation of morphological plasticity.

ecology↗

bioRxiv2018

Bacterial community dynamics during embryonic and larval development of three confamilial echinoids

Development of some animals is influenced by and, in some cases, dependent on the associated microbiota. The timing of when associated bacterial communities are established during the development of marine invertebrates and their subsequent dynamics across stages are known for only a few species. Here, we compare the bacterial communities of three confamilial echinoids from egg to juvenile using sequence-based approaches. Bacterial communities are established on unfertilized eggs and change gradually during embryonic and larval development. Despite the differences amongst these pre-metamorphic stages, approximately thirty-percent of OTUs identified in association with unfertilized egg were present in the juveniles. During embryonic development, host-associated communities diverged from the environmental microbiota but later converged following the onset of larval feeding. Taken together, the data presented here support the hypothesis that bacterial communities are established prior to fertilization and community composition shifts gradually thereafter, all while remaining distinct from the environment. Future work will need to determine the relative influence of the host and bacteria-bacteria interactions in shaping the associated bacterial community to determine the potential functional importance of bacteria during the development of larval sea urchins and benthic marine invertebrates more broadly.

developmental biology↗

bioRxiv2018

Biogeography masks diet-induced shifts in the bacterial community associated with larvae of the sea urchin Strongylocentrotus droebachiensis

Animals acclimate to changes in their environment through diverse responses, including phenotypic plasticity and shifts in their microbiome. These microbial communities are also taxonomically distinct across the geographical distribution of the host. It is less known, however, whether taxonomic differences in host-associated bacterial communities between geographically distinct populations mask shifts due to environmental changes within a population. We tested for potential ecological masking using larvae of the echinoid Strongylocentrotus droebachiensis from three coastal locations in the Pacific and Atlantic Oceans that were exposed to four feeding regimes. When considering OTU membership and the relative proportion of those taxa, the composition of the larval-associated bacterial communities were best explained by location, not feeding regime. Similarly, predicted metagenomic gene profiles from these bacterial communities were congruent with population specificity and may suggest a role in metabolism. We hypothesize that, while much of the differences in the bacterial communities is related to the large geographic distances between these locations, the predicted overlapping functions of the microbiome may relate to responding to ecological variation experienced by these larvae. Taken together, these results suggest that differences in community composition between populations masks local variation, and that scaling should be considered in when studying microbiome dynamics.

ecology↗

bioRxiv2017

A microbial perspective on the life-history evolution of marine invertebrate larvae: if, where, and when to feed

The feeding environment for planktotrophic larvae has a major impact on development and progression towards competency for metamorphosis. High phytoplankton environments that promote growth often have a greater microbial load and incidence of pathogenic microbes, while areas with lower food availability have a lower number of potential pathogens. Trade-offs between metabolic processes associated with growth and immune functionality have been described throughout the animal kingdom and may influence the life-history evolution of marine invertebrate planktotrophic larvae in these environments. Namely, to avoid potential incidences of microbial-mediated mortality and/or dysbiosis, larvae should regulate time spent between these two feeding environments. We describe here transcriptomic and microbiome data that supports this trade-off in larvae, where larvae in a well-fed environment upregulate genes associated with metabolism and may regularly enter a state of dysbiosis, resulting in mortality. To address the hypothesis that the environmental microbiota is a selective force on if, where, and when planktotrophic larvae should feed, we present a strategy for determining the specific interactions of larvae and microbes at a scale representative of their larger pelagic environment.

evolutionary biology↗