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Pseudo-nitzschia Challenged with Co-occurring Viral Communities Display Diverse Infection Phenotypes.

Carlson MC, McCary ND, Leach TS, Rocap G - Front Microbiol (2016)

Bottom Line: Diatom-virus dynamics were explored by sampling every month at two coastal and estuarine locations in Washington state, USA resulting in 41 new isolates of the pennate diatom Pseudo-nitzschia and 20 environmental virus samples.Isolates that were infected by the most viral communities also had the highest maximum observed viral titers (as high as 16000 infectious units ml(-1)).The interactions between Pseudo-nitzschia and the viral communities highlight the diversity of diatoms and emphasize the complexity and variability of diatom-virus dynamics in the ocean.

View Article: PubMed Central - PubMed

Affiliation: School of Oceanography, University of Washington Seattle, WA, USA.

ABSTRACT
Viruses are catalysts of biogeochemical cycling, architects of microbial community structure, and terminators of phytoplankton blooms. Viral lysis of diatoms, a key group of eukaryotic phytoplankton, has the potential to impact carbon export and marine food webs. However, the impact of viruses on diatom abundance and community composition is unknown. Diatom-virus dynamics were explored by sampling every month at two coastal and estuarine locations in Washington state, USA resulting in 41 new isolates of the pennate diatom Pseudo-nitzschia and 20 environmental virus samples. We conducted a total of 820 pair-wise crosses of the Pseudo-nitzschia isolates and viral communities. Viral communities infected Pseudo-nitzschia isolates in 8% of the crosses overall and 16% of crosses when the host and viral communities were isolated from the same sample. Isolates ranged in their permissivity to infection with some isolates not infected by any viral samples and others infected by up to 10 viral communities. Isolates that were infected by the most viral communities also had the highest maximum observed viral titers (as high as 16000 infectious units ml(-1)). Titers of the viral communities were host dependent, as titers for one viral sample on eight different hosts spanned four orders of magnitude. Sequencing of the Pseudo-nitzschia Internal Transcribed Spacer 1 (ITS1) of the revealed multiple subgroups of hosts with 100% ITS1 identities that were infected by different viral communities. Indeed, we repeatedly isolated groups of isolates with identical ITS1 sequences from the same water sample that displayed different viral infection phenotypes. The interactions between Pseudo-nitzschia and the viral communities highlight the diversity of diatoms and emphasize the complexity and variability of diatom-virus dynamics in the ocean.

No MeSH data available.


Related in: MedlinePlus

Percent of crosses between Pseudo-nitzschia isolates and environmental viral communities that were infectious based on the time and location of host isolation and virus community sample collection.∗ Denotes a significant of p-value = 0.009 as determined by a Chi-square test.
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Figure 3: Percent of crosses between Pseudo-nitzschia isolates and environmental viral communities that were infectious based on the time and location of host isolation and virus community sample collection.∗ Denotes a significant of p-value = 0.009 as determined by a Chi-square test.

Mentions: The 41 Pseudo-nitzschia isolates were challenged with each of the 20 environmental virus samples in replicates of 5 to create an infection network of 820 crosses. In total, 68 Pseudo-nitzschia – virus community combinations (8%) showed signs of infection, defined as the death of at least one replicate in the cross (Figure 3). Pseudo-nitzschia isolates inoculated with UV irradiated viral communities showed no signs of infection compared to medium-only controls. Hosts isolated from Penn Cove were infected by virus communities from Grays Harbor, and vice versa. Hosts and viruses that came from different times and locations were not significantly less infective than the total average. Crosses of Pseudo-nitzschia isolates with virus communities from the same time and location resulted in infection in 16% percent of crosses, double the overall infection rate (Chi-square p = 0.009) (Figure 3).


Pseudo-nitzschia Challenged with Co-occurring Viral Communities Display Diverse Infection Phenotypes.

Carlson MC, McCary ND, Leach TS, Rocap G - Front Microbiol (2016)

Percent of crosses between Pseudo-nitzschia isolates and environmental viral communities that were infectious based on the time and location of host isolation and virus community sample collection.∗ Denotes a significant of p-value = 0.009 as determined by a Chi-square test.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837327&req=5

Figure 3: Percent of crosses between Pseudo-nitzschia isolates and environmental viral communities that were infectious based on the time and location of host isolation and virus community sample collection.∗ Denotes a significant of p-value = 0.009 as determined by a Chi-square test.
Mentions: The 41 Pseudo-nitzschia isolates were challenged with each of the 20 environmental virus samples in replicates of 5 to create an infection network of 820 crosses. In total, 68 Pseudo-nitzschia – virus community combinations (8%) showed signs of infection, defined as the death of at least one replicate in the cross (Figure 3). Pseudo-nitzschia isolates inoculated with UV irradiated viral communities showed no signs of infection compared to medium-only controls. Hosts isolated from Penn Cove were infected by virus communities from Grays Harbor, and vice versa. Hosts and viruses that came from different times and locations were not significantly less infective than the total average. Crosses of Pseudo-nitzschia isolates with virus communities from the same time and location resulted in infection in 16% percent of crosses, double the overall infection rate (Chi-square p = 0.009) (Figure 3).

Bottom Line: Diatom-virus dynamics were explored by sampling every month at two coastal and estuarine locations in Washington state, USA resulting in 41 new isolates of the pennate diatom Pseudo-nitzschia and 20 environmental virus samples.Isolates that were infected by the most viral communities also had the highest maximum observed viral titers (as high as 16000 infectious units ml(-1)).The interactions between Pseudo-nitzschia and the viral communities highlight the diversity of diatoms and emphasize the complexity and variability of diatom-virus dynamics in the ocean.

View Article: PubMed Central - PubMed

Affiliation: School of Oceanography, University of Washington Seattle, WA, USA.

ABSTRACT
Viruses are catalysts of biogeochemical cycling, architects of microbial community structure, and terminators of phytoplankton blooms. Viral lysis of diatoms, a key group of eukaryotic phytoplankton, has the potential to impact carbon export and marine food webs. However, the impact of viruses on diatom abundance and community composition is unknown. Diatom-virus dynamics were explored by sampling every month at two coastal and estuarine locations in Washington state, USA resulting in 41 new isolates of the pennate diatom Pseudo-nitzschia and 20 environmental virus samples. We conducted a total of 820 pair-wise crosses of the Pseudo-nitzschia isolates and viral communities. Viral communities infected Pseudo-nitzschia isolates in 8% of the crosses overall and 16% of crosses when the host and viral communities were isolated from the same sample. Isolates ranged in their permissivity to infection with some isolates not infected by any viral samples and others infected by up to 10 viral communities. Isolates that were infected by the most viral communities also had the highest maximum observed viral titers (as high as 16000 infectious units ml(-1)). Titers of the viral communities were host dependent, as titers for one viral sample on eight different hosts spanned four orders of magnitude. Sequencing of the Pseudo-nitzschia Internal Transcribed Spacer 1 (ITS1) of the revealed multiple subgroups of hosts with 100% ITS1 identities that were infected by different viral communities. Indeed, we repeatedly isolated groups of isolates with identical ITS1 sequences from the same water sample that displayed different viral infection phenotypes. The interactions between Pseudo-nitzschia and the viral communities highlight the diversity of diatoms and emphasize the complexity and variability of diatom-virus dynamics in the ocean.

No MeSH data available.


Related in: MedlinePlus