Publications
Following publications have been announced by our department Biological Carbon Pump. For further information please contact Dr. Jana Hinners, co-author of the publications:
Krishna, S., Peterson, V., Listmann, L., & Hinners, J. (2024): Interactive effects of viral lysis and warming in a coastal ocean identified from an idealized ecosystem model. Ecological Modelling, Volume 487, 110550, doi:10.1016/j.ecolmodel.2023.110550
Abstract:
Marine viruses have been identified as key players in biogeochemical cycles and in the termination of phytoplankton blooms; however, most biogeochemical models have yet to resolve viral dynamics. Here, we incorporate a viral component into a 1D ecosystem model to explore the influence of viruses on ecosystem dynamics under current and future climatic conditions in a coastal ocean. Virus-phytoplankton interactions and zooplankton grazing were mechanistically described through size-based contact rates. The model demonstrated that the presence of viruses increased nutrient retention in the upper water column. This corresponded to a reduction in phytoplankton biomass, production of dead organic matter and transfer of biomass to higher trophic levels. Viral presence played a key role in deeper water layers, near the thermocline. While warming alone reversed these trends, the combination of warming and viral presence enhanced the effect of viruses, indicative of synergistic interaction. Our results highlight the need of incorporating viral dynamics in the existing marine ecosystem models to better predict ecosystem responses to climate change.
Walworth, N.G., Espinoza, J.L., Argyle, P.A., Hinners, J., Levine, N.M., Doblin, M.A., Dupont, C.L., & Collins, S., (2023): Genus-Wide Transcriptional Landscapes Reveal Correlated Gene Networks Underlying Microevolutionary Divergence in Diatoms. Molecular Biology and Evolution, Volume 40, Issue 10, https://doi.org/10.1093/molbev/msad218
Abstract:
Marine microbes like diatoms make up the base of marine food webs and drive global nutrient cycles. Despite their key roles in ecology, biogeochemistry, and biotechnology, we have limited empirical data on how forces other than adaptation may drive diatom diversification, especially in the absence of environmental change. One key feature of diatom populations is frequent extreme reductions in population size, which can occur both in situ and ex situ as part of bloom-and-bust growth dynamics. This can drive divergence between closely related lineages, even in the absence of environmental differences. Here, we combine experimental evolution and transcriptome landscapes (t-scapes) to reveal repeated evolutionary divergence within several species of diatoms in a constant environment. We show that most of the transcriptional divergence can be captured on a reduced set of axes, and that repeatable evolution can occur along a single major axis of variation defined by core ortholog expression comprising common metabolic pathways. Previous work has associated specific transcriptional changes in gene networks with environmental factors. Here, we find that these same gene networks diverge in the absence of environmental change, suggesting these pathways may be central in generating phenotypic diversity as a result of both selective and random evolutionary forces. If this is the case, these genes and the functions they encode may represent universal axes of variation. Such axes that capture suites of interacting transcriptional changes during diversification improve our understanding of both global patterns in local adaptation and microdiversity, as well as evolutionary forces shaping algal cultivation.
