scholarly journals Algal Diversity in Paramecium bursaria: Species Identification, Detection of Choricystis parasitica, and Assessment of the Interaction Specificity

Diversity ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 287 ◽  
Author(s):  
Felicitas E. Flemming ◽  
Alexey Potekhin ◽  
Thomas Pröschold ◽  
Martina Schrallhammer
Keyword(s):  
Molecular Markers ◽  
Host Cell ◽  
Species Identification ◽  
Green Algae ◽  
Paramecium Bursaria ◽  
Free Living ◽  
Mutualistic Symbiosis ◽  
Algal Symbionts ◽  
Chlorella Variabilis

The ‘green’ ciliate Paramecium bursaria lives in mutualistic symbiosis with green algae belonging to the species Chlorella variabilis or Micractinium conductrix. We analysed the diversity of algal endosymbionts and their P. bursaria hosts in nine strains from geographically diverse origins. Therefore, their phylogenies using different molecular markers were inferred. The green paramecia belong to different syngens of P. bursaria. The intracellular algae were assigned to Chl. variabilis, M. conductrix or, surprisingly, Choricystis parasitica. This usually free-living alga co-occurs with M. conductrix in the host’s cytoplasm. Addressing the potential status of Chor. parasitica as second additional endosymbiont, we determined if it is capable of symbiosis establishment and replication within a host cell. Symbiont-free P. bursaria were generated by cycloheximid treatment. Those aposymbiotic P. bursaria were used for experimental infections to investigate the symbiosis specificity not only between P. bursaria and Chor. parasitica but including also Chl. variabilis and M. conductrix. For each algae we observed the uptake and incorporation in individual perialgal vacuoles. These host-symbiont associations are stable since more than five months. Thus, Chor. parasitica and P. bursaria can form an intimate and long-term interaction. This study provides new insights into the diversity of P. bursaria algal symbionts.

Different physiological and molecular responses of the green algae Chlorella variabilis to long-term and short-term elevated CO2

2020 ◽  
Vol 32 (2) ◽  
pp. 951-966
Author(s):  
Chengwei Liang ◽  
Xiao Yang ◽  
Lu Wang ◽  
Xiao Fan ◽  
Xiaowen Zhang ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Green Algae ◽  
Short Term ◽  
Molecular Responses ◽  
Chlorella Variabilis

scholarly journals Endosymbiotic Green Algae in Paramecium bursaria: A New Isolation Method and a Simple Diagnostic PCR Approach for the Identification

Diversity ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 240 ◽  
Author(s):  
Christian Spanner ◽  
Tatyana Darienko ◽  
Tracy Biehler ◽  
Bettina Sonntag ◽  
Thomas Pröschold
Keyword(s):  
Green Algae ◽  
Model Organism ◽  
Morphological Characteristics ◽  
Paramecium Bursaria ◽  
Isolation Method ◽  
Specific Primers ◽  
Diagnostic Pcr ◽  
Chlorella Variabilis ◽  
The World ◽  
Axenic Cultures

Paramecium bursaria is a single-celled model organism for studying endosymbiosis among ciliates and green algae. Most strains of P. bursaria bear either Chlorella variabilis or Micractinium conductrix as endosymbionts. Both algal genera are unicellular green algae characterized by cup-shaped chloroplasts containing a single pyrenoid and reproduction by autospores. Due to their size and only few morphological characteristics, these green algae are very difficult to discriminate by microscopy only. Their cultivation is laborious and often unsuccessful, but we developed a three-step isolation method, which provided axenic cultures of endosymbionts. In addition to the time-consuming isolation, we developed a simple diagnostic PCR identification method using specific primers for C. variabilis and M. conductrix that provided reliable results. One advantage of this approach was that the algae do not have to be isolated from their host. For a comparative study, we investigated 19 strains of P. bursaria from all over the world (new isolates and available laboratory strains) belonging to the five known syngens (R1–R5). Six European ciliate strains belonging to syngens R1 and R2 bore M. conductrix as endosymbiont whereas C. variabilis was discovered in syngens R1–R5 having worldwide origins. Our results reveal the first evidence of C. variabilis as endosymbiont in P. bursaria in Europe.

scholarly journals Genetic Diversity of Symbiotic Green Algae of Paramecium bursaria Syngens Originating from Distant Geographical Locations

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 609
Author(s):  
Magdalena Greczek-Stachura ◽  
Patrycja Zagata Leśnicka ◽  
Sebastian Tarcz ◽  
Maria Rautian ◽  
Katarzyna Możdżeń
Keyword(s):  
Green Algae ◽  
Haplotype Diversity ◽  
28S Rdna ◽  
Paramecium Bursaria ◽  
Its2 Region ◽  
5.8S Rdna ◽  
Rdna Its2 ◽  
Green Algal ◽  
Chlorella Variabilis ◽  
Geographical Locations

Paramecium bursaria (Ehrenberg 1831) is a ciliate species living in a symbiotic relationship with green algae. The aim of the study was to identify green algal symbionts of P. bursaria originating from distant geographical locations and to answer the question of whether the occurrence of endosymbiont taxa was correlated with a specific ciliate syngen (sexually separated sibling group). In a comparative analysis, we investigated 43 P. bursaria symbiont strains based on molecular features. Three DNA fragments were sequenced: two from the nuclear genomes—a fragment of the ITS1-5.8S rDNA-ITS2 region and a fragment of the gene encoding large subunit ribosomal RNA (28S rDNA), as well as a fragment of the plastid genome comprising the 3′rpl36-5′infA genes. The analysis of two ribosomal sequences showed the presence of 29 haplotypes (haplotype diversity Hd = 0.98736 for ITS1-5.8S rDNA-ITS2 and Hd = 0.908 for 28S rDNA) in the former two regions, and 36 haplotypes in the 3′rpl36-5′infA gene fragment (Hd = 0.984). The following symbiotic strains were identified: Chlorella vulgaris, Chlorella variabilis, Chlorella sorokiniana and Micractinium conductrix. We rejected the hypotheses concerning (i) the correlation between P. bursaria syngen and symbiotic species, and (ii) the relationship between symbiotic species and geographic distribution.

Long-term monitoring of molecular markers can distinguish different seasonal patterns of fecal indicating bacteria sources

2015 ◽  
Vol 71 ◽  
pp. 227-243 ◽  
Author(s):  
Timothy E. Riedel ◽  
Vanessa Thulsiraj ◽  
Amity G. Zimmer-Faust ◽  
Rosi Dagit ◽  
Jenna Krug ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Seasonal Patterns ◽  
Long Term Monitoring ◽  
Term Monitoring

scholarly journals Nestling telomere shortening, but not telomere length, reflects developmental stress and predicts survival in wild birds

2014 ◽  
Vol 281 (1785) ◽  
pp. 20133287 ◽  
Author(s):  
Jelle J. Boonekamp ◽  
G. A. Mulder ◽  
H. Martijn Salomons ◽  
Cor Dijkstra ◽  
Simon Verhulst
Keyword(s):  
Telomere Length ◽  
Brood Size ◽  
Developmental Stress ◽  
Free Living ◽  
Telomere Shortening ◽  
Developmental Effects ◽  
Fitness Consequences ◽  
Developmental Conditions ◽  
Fledgling Mass

Developmental stressors often have long-term fitness consequences, but linking offspring traits to fitness prospects has remained a challenge. Telomere length predicts mortality in adult birds, and may provide a link between developmental conditions and fitness prospects. Here, we examine the effects of manipulated brood size on growth, telomere dynamics and post-fledging survival in free-living jackdaws. Nestlings in enlarged broods achieved lower mass and lost 21% more telomere repeats relative to nestlings in reduced broods, showing that developmental stress accelerates telomere shortening. Adult telomere length was positively correlated with their telomere length as nestling ( r = 0.83). Thus, an advantage of long telomeres in nestlings is carried through to adulthood. Nestling telomere shortening predicted post-fledging survival and recruitment independent of manipulation and fledgling mass. This effect was strong, with a threefold difference in recruitment probability over the telomere shortening range. By contrast, absolute telomere length was neither affected by brood size manipulation nor related to survival. We conclude that telomere loss, but not absolute telomere length, links developmental conditions to subsequent survival and suggest that telomere shortening may provide a key to unravelling the physiological causes of developmental effects on fitness.

scholarly journals Rapid evolution of decreased host susceptibility drives a stable relationship between ultrasmall parasite TM7x and its bacterial host

2018 ◽  
Vol 115 (48) ◽  
pp. 12277-12282 ◽  
Author(s):  
Batbileg Bor ◽  
Jeffrey S. McLean ◽  
Kevin R. Foster ◽  
Lujia Cen ◽  
Thao T. To ◽  
...  
Keyword(s):  
Host Cell ◽  
Rapid Evolution ◽  
Host Population ◽  
Host Cells ◽  
Host Susceptibility ◽  
Bacterial Host ◽  
Narrow Host Range ◽  
Stable Relationship ◽  
Candidate Phyla Radiation

Around one-quarter of bacterial diversity comprises a single radiation with reduced genomes, known collectively as the Candidate Phyla Radiation. Recently, we coisolated TM7x, an ultrasmall strain of the Candidate Phyla Radiation phylum Saccharibacteria, with its bacterial host Actinomyces odontolyticus strain XH001 from human oral cavity and stably maintained as a coculture. Our current work demonstrates that within the coculture, TM7x cells establish a long-term parasitic association with host cells by infecting only a subset of the population, which stay viable yet exhibit severely inhibited cell division. In contrast, exposure of a naïve A. odontolyticus isolate, XH001n, to TM7x cells leads to high numbers of TM7x cells binding to each host cell, massive host cell death, and a host population crash. However, further passaging reveals that XH001n becomes less susceptible to TM7x over time and enters a long-term stable relationship similar to that of XH001. We show that this reduced susceptibility is driven by rapid host evolution that, in contrast to many forms of phage resistance, offers only partial protection. The result is a stalemate where infected hosts cannot shed their parasites; nevertheless, parasite load is sufficiently low that the host population persists. Finally, we show that TM7x can infect and form stable long-term relationships with other species in a single clade of Actinomyces, displaying a narrow host range. This system serves as a model to understand how parasitic bacteria with reduced genomes such as those of the Candidate Phyla Radiation have persisted with their hosts and ultimately expanded in their diversity.

scholarly journals A Stochastic Model for Virus Growth in a Cell Population

2014 ◽  
Vol 51 (3) ◽  
pp. 599-612 ◽  
Author(s):  
J. E. Björnberg ◽  
T. Britton ◽  
E. I. Broman ◽  
E. Natan
Keyword(s):  
Stochastic Model ◽  
Host Cell ◽  
Cell Population ◽  
Branching Process ◽  
Virus Population ◽  
Virus Growth ◽  
Optimal Balance ◽  
Large Numbers ◽  
A Cell

In this work we introduce a stochastic model for the spread of a virus in a cell population where the virus has two ways of spreading: either by allowing its host cell to live and duplicate, or by multiplying in large numbers within the host cell, causing the host cell to burst and thereby let the virus enter new uninfected cells. The model is a kind of interacting Markov branching process. We focus in particular on the probability that the virus population survives and how this depends on a certain parameter λ which quantifies the ‘aggressiveness’ of the virus. Our main goal is to determine the optimal balance between aggressive growth and long-term success. Our analysis shows that the optimal strategy of the virus (in terms of survival) is obtained when the virus has no effect on the host cell's life cycle, corresponding to λ = 0. This is in agreement with experimental data about real viruses.

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