Poster abstracts

Poster number 11 submitted by Alfonso Carrillo

Sub-daily virus sampling reveals population, but not community level differences at the Bermuda Atlantic Time Series

Alfonso Carrillo (The Ohio State University), Emily Hageman, Kimberley Ndlovu, Christine L. Sun, Matthew B. Sullivan (The Ohio State University), Daniel Muratore (Georgia Institute of Technology, Santa Fe Institute), Naomi E. Gilbert (Lawrence Livermore National Laboratory), Joshua S. Weitz (The University of Maryland), Steven W. Wilhelm (University of Tennessee-Knoxville)

Abstract:
Oligotrophic oceans are nutrient-limited and thermally stratified waters that represents the majority of ocean surface area and carbon cycling in these regions need to be understood as thermal stratification and ocean nutrient loss are predicted to intensify under future climate scenarios. The Bermuda Atlantic Time Series (BATS) acts as a model oligotrophic ocean ecosystem studied via monthly sampling since 1988. Microbes in these oceans contribute to biogeochemical cycling and ecosystem function but do so under constraints imposed by viruses whose dynamics are particularly understudied. Here we complement ocean time series studies by establishing a high-resolution time series dataset (every 4 or 12 hours, respectively for surface versus deep chlorophyll maximum waters, for 112 hours) at the BATS station during 2019 late summer-stratified conditions to establish a baseline understanding of virus community dynamics using de novo viromes generated through 39 large-scale virus concentrates. Aggregated community diversity metrics such as Inverse Simpsons and bray-curtis dissimilarity were consistent at each depth over time, but distinct between depths. Abundances of particular viral populations did significantly change temporally. Viral population abundance patterns inferred from metagenomic sequencing either lacked any diel periodicity (87.01%), peaked in abundance during the daytime (11.02%), or peaked in abundance during the nighttime (1.97%). Host predictions revealed viruses with 24-hour cycles in abundance tended to have predicted hosts with day/night differences in surface metagenomic abundances. Host predictions within diel cycling viruses in the DCM were also found to be different to those in the non-diel viruses. Surprisingly, virus-encoded metabolic genes were relatively invariant between the diel and non-diel viruses, suggesting that other genes drive niche differentiation in these populations (selection analyses are ongoing).

References:
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Roux, S., Brum, J. R., Dutilh, B. E., Sunagawa, S., Duhaime, M. B., Loy, A., ... & Sullivan, M. B. (2016). Ecogenomics and potential biogeochemical impacts of globally abundant ocean viruses. Nature, 537(7622), 689-693.

Vik, D., Gazitúa, M. C., Sun, C. L., Zayed, A. A., Aldunate, M., Mulholland, M. R., Ulloa, O., & Sullivan, M. B. (2021). Genome-resolved viral ecology in a marine oxygen minimum zone. Environmental Microbiology, 23(6), 2858–2874. https://doi.org/10.1111/1462-2920.15313

Keywords: Viral Ecology, Phages, Marine Science