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 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.

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.

scholarly journals Morphological Characteristics, Classifications and Difficulties in the Use of Diagnostic Criteria for Serrated Lesions of the Large Intestine

2021 ◽  
Author(s):  
Cesar de Souza Bastos Junior ◽  
Vera Lucia Nunes Pannain ◽  
Adriana Caroli-Bottino
Keyword(s):  
Diagnostic Criteria ◽  
Morphological Characteristics ◽  
World Health ◽  
Diagnostic Tools ◽  
Serrated Adenoma ◽  
The Past ◽  
The World ◽  
Serrated Lesions ◽  
Health Organization

Abstract Introduction Colorectal carcinoma (CRC) is the most common gastrointestinal neoplasm in the world, accounting for 15% of cancer-related deaths. This condition is related to different molecular pathways, among them the recently described serrated pathway, whose characteristic entities, serrated lesions, have undergone important changes in their names and diagnostic criteria in the past thirty years. The multiplicity of denominations and criteria over the last years may be responsible for the low interobserver concordance (IOC) described in the literature. Objectives The present study aims to describe the evolution in classification of serrated lesions, based on the last three publications of the World Health Organization (WHO) and the reproducibility of these criteria by pathologists, based on the evaluation of the IOC. Methods A search was conducted in the PubMed, ResearchGate and Portal Capes databases, with the following terms: sessile serrated lesion; serrated lesions; serrated adenoma; interobserver concordance; and reproducibility. Articles published since 1990 were researched. Results and Discussion The classification of serrated lesions in the past thirty years showed different denominations and diagnostic criteria. The reproducibility and IOC of these criteria in the literature, based on the kappa coefficient, varied in most studies, from very poor to moderate. Conclusions Interobserver concordance and the reproducibility of microscopic criteria may represent a limitation for the diagnosis and appropriate management of these lesions. It is necessary to investigate diagnostic tools to improve the performance of the pathologist's evaluation, for better concordance, and, consequently, adequate diagnosis and treatment.

scholarly journals Effects of Long-Wave UV Light on Monilinia Growth and Identification of Species

Plant Disease ◽  
1999 ◽  
Vol 83 (1) ◽  
pp. 62-65 ◽  
Author(s):  
A. De Cal ◽  
P. Melgarejo
Keyword(s):  
Short Distance ◽  
Mycelial Growth ◽  
Uv Light ◽  
Dark Period ◽  
Morphological Characteristics ◽  
Potato Dextrose Agar ◽  
Long Wave ◽  
The World ◽  
Identification Of Species ◽  
Respective Species

The effect of long-wave UV/dark period on mycelial growth of 46 isolates of Monilinia sp. collected in Spain and 16 isolates collected from other parts of the world was investigated. Typical isolates of M. laxa, M. fructigena, and M. fructicola were grown in the dark and identified by morphological characteristics. Long-wave UV/dark conditions reduced the growth rates of M. laxa, M. fructigena, and M. fructicola on potato dextrose agar. All isolates of M. fructigena grew more slowly than those of M. fructicola. Typical and atypical isolates of M. fructigena and M. fructicola were placed in their respective species based on long-wave UV/dark growth rate data. M. laxa isolates were readily distinguished by the short distance from their conidium to the first germ tube branch. The involvement of different photoreceptors in photoresponses by M. fructicola and M. fructigena is discussed. Differences in mycelial growth under long-wave UV may be a useful tool to identify Monilinia spp.

scholarly journals Current Classification and Diversity of Fusarium Species Complex, the Causal Pathogen of Fusarium Wilt Disease of Banana in Malaysia

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1955
Author(s):  
Anysia Hedy Ujat ◽  
Ganesan Vadamalai ◽  
Yukako Hattori ◽  
Chiharu Nakashima ◽  
Clement Kiing Fook Wong ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Species Complex ◽  
Phylogenetic Trees ◽  
Fusarium Species ◽  
Morphological Characteristics ◽  
Pathogenicity Test ◽  
Fusarium Spp ◽  
Specific Primers ◽  
Fusarium Oxysporum Species Complex

The re-emergence of the Fusarium wilt caused by Fusarium odoratissimum (F. odoratissimum) causes global banana production loss. Thirty-eight isolates of Fusarium species (Fusarium spp.) were examined for morphological characteristics on different media, showing the typical Fusarium spp. The phylogenetic trees of Fusarium isolates were generated using the sequences of histone gene (H3) and translation elongation factor gene (TEF-1α). Specific primers were used to confirm the presence of F. odoratissimum. The phylogenetic trees showed the rich diversity of the genus Fusarium related to Fusarium wilt, which consists of F. odoratissimum, Fusarium grosmichelii, Fusarium sacchari, and an unknown species of the Fusarium oxysporum species complex. By using Foc-TR4 specific primers, 27 isolates were confirmed as F. odoratissimum. A pathogenicity test was conducted for 30 days on five different local cultivars including, Musa acuminata (AAA, AA) and Musa paradisiaca (AAB, ABB). Although foliar symptoms showed different severity of those disease progression, vascular symptoms of the inoculated plantlet showed that infection was uniformly severe. Therefore, it can be concluded that the Fusarium oxysporum species complex related to Fusarium wilt of banana in Malaysia is rich in diversity, and F. odoratissimum has pathogenicity to local banana cultivars in Malaysia regardless of the genotype of the banana plants.

scholarly journals Metabolic Symbiosis Facilitates Species Coexistence and Generates Light-Dependent Priority Effects

2021 ◽  
Vol 8 ◽  
Author(s):  
Veronica Hsu ◽  
Holly V. Moeller
Keyword(s):  
Carbon Source ◽  
Community Composition ◽  
Green Algae ◽  
Species Interactions ◽  
Species Coexistence ◽  
Priority Effects ◽  
Competitive Interactions ◽  
Paramecium Bursaria ◽  
Mutual Benefit ◽  
Cascading Effects

Metabolic symbiosis is a form of symbiosis in which organisms exchange metabolites, typically for mutual benefit. For example, acquired phototrophs like Paramecium bursaria obtain photosynthate from endosymbiotic green algae called Chlorella. In addition to facilitating the persistence of P. bursaria by providing a carbon source that supplements P. bursaria’s heterotrophic digestion of bacteria, symbiotic Chlorella may impact competitive interactions between P. bursaria and other bacterivores, with cascading effects on community composition and overall diversity. Here, we tested the effects of metabolic symbiosis on coexistence by assessing the impacts of acquired phototrophy on priority effects, or the effect of species arrival order on species interactions, between P. bursaria and its competitor Colpidium. Our results suggest light-dependent priority effects. The acquired phototroph benefited from metabolic symbiosis during sequential arrival of each organism in competition, and led to increased growth of late-arriving Colpidium. These findings demonstrate that understanding the consequences of priority effects for species coexistence requires consideration of metabolic symbiosis.

scholarly journals Presence of mismatches between diagnostic PCR assays and coronavirus SARS-CoV-2 genome

2020 ◽  
Vol 7 (6) ◽  
pp. 200636 ◽  
Author(s):  
Kashif Aziz Khan ◽  
Peter Cheung
Keyword(s):  
World Health ◽  
Current Standard ◽  
Policy Makers ◽  
Diagnostic Pcr ◽  
Diagnostic Assays ◽  
The World ◽  
Polymerase Chain ◽  
Pcr Assays ◽  
Health Organization ◽  
Viral Sequences

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; initially named as 2019-nCoV) is responsible for the recent COVID-19 pandemic and polymerase chain reaction (PCR) is the current standard method for its diagnosis from patient samples. This study conducted a reassessment of published diagnostic PCR assays, including those recommended by the World Health Organization (WHO), through the evaluation of mismatches with publicly available viral sequences. An exhaustive evaluation of the sequence variability within the primer/probe target regions of the viral genome was performed using more than 17 000 viral sequences from around the world. The analysis showed the presence of mutations/mismatches in primer/probe binding regions of 7 assays out of 27 assays studied. A comprehensive bioinformatics approach for in silico inclusivity evaluation of PCR diagnostic assays of SARS-CoV-2 was validated using freely available software programs that can be applied to any diagnostic assay of choice. These findings provide potentially important information for clinicians, laboratory professionals and policy-makers.

A new record of the copepod Xanthocalanus agilis Giesbrecht, 1893 (Calanoida, Phaennidae) from the South China Sea

Crustaceana ◽  
2019 ◽  
Vol 92 (7) ◽  
pp. 789-797
Author(s):  
Y. Z. Feng ◽  
Z. S. Liu
Keyword(s):  
South China Sea ◽  
South China ◽  
World Ocean ◽  
Morphological Characteristics ◽  
Distal Segment ◽  
The South China Sea ◽  
The South ◽  
China Sea ◽  
Deep Waters ◽  
The World

Abstract The genus Xanthocalanus inhabits the intermediate and deep waters of the world ocean. The present study records and describes the first female individual of Xanthocalanus agilis Giesbrecht, 1893, collected in the South China Sea (13°0.21′N 113°0.21′E) at depths of 500-800 m. This species was identified by the following morphological characteristics: (i) rostrum with 2 slender filaments; (ii) posterolateral corners of fifth thoracic somite protuberant and triangular, reaching the posterior margin of genital somite; (iii) first segment of fifth pereiopod (P5) with a list of inner marginal spinules, distal segment short with 3 robust terminal spines. This finding expands the known global and vertical distribution of X. agilis.

Two species of Agaricus subg. Minoriopsis from Mexico

Phytotaxa ◽  
2019 ◽  
Vol 404 (3) ◽  
pp. 91
Author(s):  
JIE CHEN ◽  
PHILIPPE CALLAC ◽  
RÉGULO CARLOS LLARENA-HERNÁNDEZ ◽  
GERARDO GERARDO MATA
Keyword(s):  
New Species ◽  
New Record ◽  
Phylogenetic Analyses ◽  
Morphological Characteristics ◽  
Molecular Data ◽  
Edible Fungi ◽  
The World ◽  
Wild Edible Fungi ◽  
A New Species ◽  
Taxonomic System

Agaricus is a species-rich genus with more than 500 species over the world. Recent studies on tropical Agaricus revealed new tropical clades and a revised taxonomic system was consequently developed. Agaricus subg. Minoriopsis, a sixth subgenus was recently added, comprising species exclusively from the Americas. The diversity of Agaricus is little studied in Mexico, despite this country has a long history in the consumption of wild edible fungi. In this paper, we introduce a new species A. guzmanii and a new record for A. globocystidiatus from Mexico based on morphological characteristics and molecular data. Phylogenetic analyses indicate that they belong to A. subg. Minoriopsis.

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