@article {walde_viral_2023, title = {Viral infection impacts the 3D subcellular structure of the abundant marine diatom Guinardia delicatula}, journal = {Frontiers in Marine Science}, volume = {9}, year = {2023}, abstract = {Viruses are key players in marine ecosystems where they infect abundant marine microbes. RNA viruses are emerging as key members of the marine virosphere. They have recently been identified as a potential source of mortality in diatoms, a group of microalgae that accounts for roughly 40\% of the primary production in the ocean. Despite their likely importance, their impacts on host populations and ecosystems remain difficult to assess. In this study, we introduce an innovative approach that combines automated 3D confocal microscopy with quantitative image analysis and physiological measurements to expand our understanding of viral infection. We followed different stages of infection of the bloom-forming diatom Guinardia delicatula by the RNA virus GdelRNAV-04 until the complete lysis of the host. From 20h after infection, we observed quantifiable changes in subcellular host morphology and biomass. Our microscopy monitoring also showed that viral infection of G. delicatula induced the formation of auxospores as a probable defense strategy against viruses. Our method enables the detection of discriminative morphological features on the subcellular scale and at high throughput for comparing populations, making it a promising approach for the quantification of viral infections in the field in the future.}, keywords = {RCC3083, RCC5812}, issn = {2296-7745}, doi = {10.3389/fmars.2022.1034235}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2022.1034235}, author = {Walde, Marie and Camplong, Cyprien and de Vargas, Colomban and Baudoux, Anne-claire and Simon, Nathalie} } @article {Arsenieff2020, title = {Diversity and dynamics of relevant nanoplanktonic diatoms in the Western English Channel}, journal = {The ISME Journal}, year = {2020}, note = {Publisher: Springer US tex.mendeley-tags: RCC4657,RCC4658,RCC4659,RCC4660,RCC4661,RCC4662,RCC4663,RCC4664,RCC4665,RCC4666,RCC5154,RCC5839,RCC5840,RCC5841,RCC5842,RCC5843,RCC5844,RCC5845,RCC5846,RCC5847,RCC5848,RCC5849,RCC5850,RCC5851,RCC5852,RCC5853,RCC5854,RCC5855,RCC5856,RCC5857,RCC5859,RCC5860,RCC5861,RCC5862,RCC5863,RCC5864,RCC5865,RCC5866,RCC5867,RCC5868,RCC5869,RCC5870,RCC5871,RCC5872,RCC5873,RCC5875,RCC5876,RCC5877,RCC5878,RCC5879,RCC5880,RCC5881,RCC5882,RCC5883,RCC5884,RCC5885,RCC5886,RCC5887,RCC5921}, month = {apr}, keywords = {RCC4657, RCC4658, RCC4659, RCC4660, RCC4661, RCC4662, RCC4663, RCC4664, RCC4665, RCC4666, RCC5154, RCC5839, RCC5840, RCC5841, RCC5842, RCC5843, RCC5844, RCC5845, RCC5846, RCC5847, RCC5848, RCC5849, RCC5850, RCC5851, RCC5852, RCC5853, RCC5854, RCC5855, RCC5856, RCC5857, RCC5859, RCC5860, RCC5861, RCC5862, RCC5863, RCC5864, RCC5865, RCC5866, RCC5867, RCC5868, RCC5869, RCC5870, RCC5871, RCC5872, RCC5873, RCC5875, RCC5876, RCC5877, RCC5878, RCC5879, RCC5880, RCC5881, RCC5882, RCC5883, RCC5884, RCC5885, RCC5886, RCC5887, RCC5921}, issn = {1751-7362}, doi = {10.1038/s41396-020-0659-6}, url = {http://dx.doi.org/10.1038/s41396-020-0659-6 http://www.nature.com/articles/s41396-020-0659-6}, author = {Arsenieff, Laure and Le Gall, Florence and Rigaut-jalabert, Fabienne and Mah{\'e}, Fr{\'e}d{\'e}ric and Sarno, Diana and Gouhier, L{\'e}na and Baudoux, Anne-claire and Simon, Nathalie} } @article {Demory2020, title = {A thermal trade-off between viral production and degradation drives phytoplankton-virus population dynamics}, journal = {bioRxiv}, year = {2020}, note = {Publisher: Cold Spring Harbor Laboratory tex.mendeley-tags: RCC4229,RCC4265,RCC451,RCC4523,RCC829,RCC834}, month = {aug}, pages = {2020.08.18.256156}, abstract = {Marine viruses interact with their microbial hosts in dynamic environments shaped by variations in abiotic factors, including temperature. However, the impacts of temperature on viral infection of phytoplankton are not well understood. Here we coupled mathematical modeling with experimental datasets to explore the effect of temperature on three Micromonas-prasinovirus pairs. Our model shows the negative consequences of high temperatures on infection and suggests a temperature-dependent threshold between viral production and degradation. Modeling long-term dynamics in environments with different average temperatures revealed the potential for long-term host-virus coexistence, epidemic free, or habitat loss states. Hence, we generalized our model to global sea surface temperature of present and future seas and show that climate change may influence virus-host dynamics differently depending on the virus-host pair. Our study suggests that temperature-dependent changes in the infectivity of virus particles may lead to shifts in virus-host habitats in warmer oceans, analogous to projected changes in the habitats of macro-and microorganisms .}, keywords = {RCC4229, RCC4265, RCC451, RCC4523, RCC829, RCC834}, doi = {10.1101/2020.08.18.256156}, url = {https://doi.org/10.1101/2020.08.18.256156}, author = {Demory, David and Weitz, Joshua S and Baudoux, Anne-claire and Touzeau, Suzanne and Simon, Natalie and Rabouille, Sophie and Sciandra, Antoine and Bernard, Olivier} } @article {Arsenieff2019, title = {First viruses infecting the marine diatom guinardia delicatula}, journal = {Frontiers in Microbiology}, volume = {9}, number = {January}, year = {2019}, note = {tex.mendeley-tags: RCC1000,RCC2023,RCC3046,RCC3083,RCC3093,RCC3101,RCC4657,RCC4659,RCC4660,RCC4667,RCC4834,RCC5154,RCC5777,RCC5778,RCC5779,RCC5780,RCC5781,RCC5782,RCC5783,RCC5784,RCC5785,RCC5787,RCC5788,RCC5789,RCC5790,RCC5792,RCC5793,RCC5794,RCC80}, month = {jan}, keywords = {diatoms, genomics, host-virus dynamics, RCC1000, RCC2023, RCC3046, RCC3083, RCC3093, RCC3101, RCC4657, RCC4659, RCC4660, RCC4667, RCC4834, RCC5154, RCC5777, RCC5778, RCC5779, RCC5780, RCC5781, RCC5782, RCC5783, RCC5784, RCC5785, RCC5787, RCC5788, RCC5789, RCC5790, RCC5792, RCC5793, RCC5794, RCC80, single-stranded RNA viruses, Western English Channel}, issn = {1664-302X}, doi = {10.3389/fmicb.2018.03235}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2018.03235/full}, author = {Arsenieff, Laure and Simon, Nathalie and Rigaut-jalabert, Fabienne and Le Gall, Florence and Chaffron, Samuel and Corre, Erwan and Com, Emmanuelle and Bigeard, Estelle and Baudoux, Anne-claire} } @article {Demory2019, title = {Picoeukaryotes of the Micromonas genus: sentinels of a warming ocean}, journal = {The ISME Journal}, volume = {13}, number = {1}, year = {2019}, note = {tex.ids= Demory2018 tex.mendeley-tags: RCC114,RCC1697,RCC1862,RCC2257,RCC2306,RCC299,RCC451,RCC497,RCC746,RCC829,RCC834 publisher: Nature Publishing Group}, month = {jan}, pages = {132{\textendash}146}, abstract = {Photosynthetic picoeukaryotesx in the genus Micromonas show among the widest latitudinal distributions on Earth, experiencing large thermal gradients from poles to tropics. Micromonas comprises at least four different species often found in sympatry. While such ubiquity might suggest a wide thermal niche, the temperature response of the different strains is still unexplored, leaving many questions as for their ecological success over such diverse ecosystems. Using combined experiments and theory, we characterize the thermal response of eleven Micromonas strains belonging to four species. We demonstrate that the variety of specific responses to temperature in the Micromonas genus makes this environmental factor an ideal marker to describe its global distribution and diversity. We then propose a diversity model for the genus Micromonas, which proves to be representative of the whole phytoplankton diversity. This prominent primary producer is therefore a sentinel organism of phytoplankton diversity at the global scale. We use the diversity within Micromonas to anticipate the potential impact of global warming on oceanic phytoplankton. We develop a dynamic, adaptive model and run forecast simulations, exploring a range of adaptation time scales, to probe the likely responses to climate change. Results stress how biodiversity erosion depends on the ability of organisms to adapt rapidly to temperature increase.}, keywords = {Biogeography, change ecology, Climate, microbial ecology, RCC114, RCC1697, RCC1862, RCC2257, RCC2306, RCC299, RCC451, RCC497, RCC746, RCC829, RCC834}, issn = {1751-7362}, doi = {10.1038/s41396-018-0248-0}, url = {http://www.nature.com/articles/s41396-018-0248-0}, author = {Demory, David and Baudoux, Anne-claire and Monier, Adam and Simon, Nathalie and Six, Christophe and Ge, Pei and Rigaut-jalabert, Fabienne and Marie, Dominique and Sciandra, Antoine and Bernard, Olivier and Rabouille, Sophie} } @article {Demory2017, title = {Temperature is a key factor in Micromonas{\textendash}virus interactions}, journal = {The ISME Journal}, volume = {11}, number = {3}, year = {2017}, note = {Publisher: Nature Publishing Group tex.mendeley-tags: 2017,RCC4229,RCC4253,RCC4265,RCC451,RCC829,RCC834,sbr?hyto$_\textrmd$ipo,sbr?hyto?app}, month = {mar}, pages = {601{\textendash}612}, abstract = {The genus Micromonas comprises phytoplankton that show among the widest latitudinal distributions on Earth, and members of this genus are recurrently infected by prasinoviruses in contrasted thermal ecosystems. In this study, we assessed how temperature influences the interplay between the main genetic clades of this prominent microalga and their viruses. The growth of three Micromonas strains (Mic-A, Mic-B, Mic-C) and the stability of their respective lytic viruses (MicV-A, MicV-B, MicV-C) were measured over a thermal range of 4{\textendash}32.5 {\textdegree}C. Similar growth temperature optima (Topt) were predicted for all three hosts but Mic-B exhibited a broader thermal tolerance than Mic-A and Mic-C, suggesting distinct thermoacclimation strategies. Similarly, the MicV-C virus displayed a remarkable thermal stability compared with MicV-A and MicV-B. Despite these divergences, infection dynamics showed that temperatures below Topt lengthened lytic cycle kinetics and reduced viral yield and, notably, that infection at temperatures above Topt did not usually result in cell lysis. Two mechanisms operated depending on the temperature and the biological system. Hosts either prevented the production of viral progeny or maintained their ability to produce virions with no apparent cell lysis, pointing to a possible switch in the viral life strategy. Hence, temperature changes critically affect the outcome of Micromonas infection and have implications for ocean biogeochemistry and evolution.}, keywords = {2017, RCC4229, RCC4253, RCC4265, RCC451, RCC829, RCC834, sbr?hyto$_\textrmd$ipo, sbr?hyto?app}, issn = {1751-7362}, doi = {10.1038/ismej.2016.160}, url = {http://dx.doi.org/10.1038/ismej.2016.160 http://www.nature.com/doifinder/10.1038/ismej.2016.160}, author = {Demory, David and Arsenieff, Laure and Simon, Nathalie and Six, Christophe and Rigaut-jalabert, Fabienne and Marie, Dominique and Ge, Pei and Bigeard, Estelle and Jacquet, St{\'e}phan and Sciandra, Antoine and Bernard, Olivier and Rabouille, Sophie and Baudoux, Anne-claire} }