Variation in resource competition traits among Microcystis strains is affected by their microbiomes

mLife, Journal Year: 2023, Volume and Issue: 2(4), P. 401 - 415

Published: Dec. 1, 2023

Abstract Freshwater harmful algal blooms are often dominated by Microcystis , a phylogenetically cohesive group of cyanobacteria marked extensive genetic and physiological diversity. We have previously shown that this diversity the presence microbiome heterotrophic bacteria influences competitive interactions with eukaryotic phytoplankton. In study, we sought to explain these observations characterizing Monod equation parameters for resource usage (maximum growth rate μ max half‐saturation value K s, quota) as function N P levels four strains (NIES‐843, PCC 9701, 7806 [WT], Δ mcyB ) in absence derived from isolated Lake Erie. Results indicated limited differences maximum rates but more pronounced values among strains. The largest impact was reducing minimal nitrogen concentration sustaining half saturation values, variable results depending on strain. also differed each other their quotas extent which affected them. Our data highlight importance altering ‐intrinsic traits, strain hierarchies, thus bloom dynamics. As quota, s commonly used models blooms, our suggest model improvement may be possible incorporating genotype dependencies resource‐use parameters.

Language: Английский

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From colonial clusters to colonial sheaths: Imaging flow cytometry analysis of Microcystis morphospecies dynamics in mesocosm and links to CyanoHABs management

Ecological Indicators, Journal Year: 2024, Volume and Issue: 163, P. 112100 - 112100

Published: May 8, 2024

The alarming increase in the frequency of blooms Microcystis freshwater lakes and reservoirs occurs worldwide, with major implications for their ecosystem functioning water quality. dominance is tightly related to colonial formation by Microcystis. However, studies development morphospecies are rare. This research applied FlowCAM-based imaging flow cytometry analyze mesocosms mimicking eutrophic shallow effect temperature changes. A significant positive association was found between M. ichtyoblabe, aeruginosa, smithii colonies, particularly high-temperature tanks, suggesting that these belong one ecocluster, which supports hypothesis central transition pathways small clusters cells represented an important stage sequence bloom were associated forms. correlation analysis showed higher pH positively correlated abundance M.wesenbergii independently sheaths' abundances increased following a maximum abundance, reaching numbers (thousands), majority sheaths contained at least some cells. We hypothesize may be crucial spp. dispersal represent obligatory colonies development. protect against environmental stress factors, improve cell survival low nutrient levels, participate spreading. Our findings can applicable early CyanoHAB detection management dispersal.

Language: Английский

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Hidden genomic diversity drives niche partitioning in a cosmopolitan eukaryotic picophytoplankton

The ISME Journal, Journal Year: 2024, Volume and Issue: 18(1)

Published: Jan. 1, 2024

Abstract Marine eukaryotic phytoplankton are fundamental to the marine food web, yet lack of reference genomes or just a single genome representing taxon has led an underestimation their taxonomic, adaptive, and functional diversity. Here, we integrated strain isolation with metagenomic binning recover from cosmopolitan picophytoplankton genus Bathycoccus, traditionally considered monospecific. Our recovery analysis 37 Bathycoccus delineated global genomic diversity established four evolutionary clades (BI, BII, BIII, BIV). abundance survey revealed well-differentiated ecological niches distinct biogeographic distributions for each clade, predominantly shaped by temperature, salinity, nutrient availability. Comparative genomics analyses further clade-specific traits that underpin niche adaptation contribute prevalence Bathycoccus. findings underscore temperature as major driver diversification in this genus, clade divergences coinciding paleoclimatic events influenced contemporary thermal niches. Moreover, unique enrichment C2H2 zinc finger ankyrin repeat gene families polar-adapted suggests previously unrecognized cold-adaptation mechanisms phytoplankton. study offers comprehensive landscape crucial picophytoplankton, providing insights into microdiversity adaptive evolution response changing environments.

Language: Английский

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Structural and kinetic insights into tRNA promoter engagement by yeast general transcription factor TFIIIC

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 28, 2024

Abstract Transcription of tRNA genes by RNA polymerase III requires the general transcription factor IIIC (TFIIIC), which recognizes intragenic A-box and B-box DNA motifs type II gene promoters. However, underlying mechanism has remained elusive, in part due to missing structural information for recognition. In this study, we use single-particle cryo-EM single-molecule FRET (smFRET) reveal real-time kinetic insights into how 520 kDa yeast TFIIIC complex engages A- context a promoter. Cryo-EM structures τA τB subcomplexes bound were obtained at 3.7 2.5 Å resolution, respectively, while single particle mapping determined specific distance relative orientation revealing fully engaged state TFIIIC. smFRET experiments show that overall recruitment residence times on are primarily governed recognition, footprinting suggest key role TFIIIB Pol following recognition

Language: Английский

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Nanoscale profiling of evolving intermolecular interactions in ageing FUS condensates

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Dec. 23, 2023

Abstract In addition to the native state, proteins can form liquid-like condensates, viscoelastic such as gels, well solid-like amyloid fibrils, crystals and amorphous materials. The material properties of these condensates play important roles in their cellular functions, with aberrant liquid-to-solid phase transitions having been implicated neurodegenerative diseases. However, molecular changes resultant across whole space are complex yet be fully understood. extreme sensitivity environment, which enables biological function, is also what makes protein particularly challenging experimental targets. Here, we provide a characterisation ageing behaviour full-length fused sarcoma (FUS) protein. We achieve this goal by using microfluidic sample deposition technology enable application surface-based techniques study condensates. first demonstrate that maintain relevant structural features physiologically-relevant conditions on surfaces. Then, combination atomic force microscopy vibrational spectroscopy, characterise spatio-temporal structure mechanical reveal local individual observe initially dynamic, fluid-like undergo global increase elastic response conferred an density cation-π intermolecular interactions. Solid-like structures at condensate-solvent interfaces, before heterogeneously propagating throughout aged fluid core. These solid composed heterogenous, non-amyloid β-sheets, stabilised hydrogen-bonding interactions not observed state. Overall, identifies conformations associated different physical states FUS establishing platform understand role condensate function dysfunction.

Language: Английский

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