scholarly journals “Candidatus Mystax nordicus” Aggregates with Mitochondria of Its Host, the Ciliate Paramecium nephridiatum

Diversity ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 251
Author(s):  
Aleksandr Korotaev ◽  
Konstantin Benken ◽  
Elena Sabaneyeva

Extensive search for new endosymbiotic systems in ciliates occasionally reverts us to the endosymbiotic bacteria described in the pre-molecular biology era and, hence, lacking molecular characterization. A pool of these endosymbionts has been referred to as a hidden bacterial biodiversity from the past. Here, we provide a description of one of such endosymbionts, retrieved from the ciliate Paramecium nephridiatum. This curve-shaped endosymbiont (CS), which shared the host cytoplasm with recently described “Candidatus Megaira venefica”, was found in the same host and in the same geographic location as one of the formerly reported endosymbiotic bacteria and demonstrated similar morphology. Based on morphological data obtained with DIC, TEM and AFM and molecular characterization by means of sequencing 16S rRNA gene, we propose a novel genus, “Candidatus Mystax”, with a single species “Ca. Mystax nordicus”. Phylogenetic analysis placed this species in Holosporales, among Holospora-like bacteria. Contrary to all Holospora species and many other Holospora-like bacteria, such as “Candidatus Gortzia”, “Candidatus Paraholospora” or “Candidatus Hafkinia”, “Ca. Mystax nordicus” was never observed inside the host nucleus. “Ca. Mystax nordicus” lacked infectivity and killer effect. The striking peculiarity of this endosymbiont was its ability to form aggregates with the host mitochondria, which distinguishes it from Holospora and Holospora-like bacteria inhabiting paramecia.

1994 ◽  
Vol 107 (2) ◽  
pp. 649-657
Author(s):  
G.I. McFadden ◽  
P.R. Gilson ◽  
S.E. Douglas

Cryptomonad algae contain a photosynthetic, eukaryotic endosymbiont. The endosymbiont is much reduced but retains a small nucleus. DNA from this endosymbiont nucleus encodes rRNAs, and it is presumed that these rRNAs are incorporated into ribosomes. Surrounding the endosymbiont nucleus is a small volume of cytoplasm proposed to be the vestigial cytoplasm of the endosymbiont. If this compartment is indeed the endosymbiont's cytoplasm, it would be expected to contain ribosomes with components encoded by the endosymbiont nucleus. In this paper, we used in situ hybridization to localize rRNAs encoded by the endosymbiont nucleus of the cryptomonad alga, Cryptomonas phi. Transcripts of the endosymbiont rRNA gene were observed within the endosymbiont nucleus, and in the compartment thought to represent the endosymbiont's cytoplasm. These results indicate that the endosymbiont produces its own set of cytoplasmic translation machinery. We also localized transcripts of the host nucleus rRNA gene. These transcripts were found in the nucleolus of the host nucleus, and throughout the host cytoplasm, but never in the endosymbiont compartment. Our rRNA localizations indicate that the cryptomonad cell produces two different of sets of cytoplasmic-type ribosomes in two separate subcellular compartments. The results suggest that there is no exchange of rRNAs between these compartments. We also used the probe specific for the endosymbiont rRNA gene to identify chromosomes from the endosymbiont nucleus in pulsed field gel electrophoresis. Like other cryptomonads, the endosymbiont nucleus of Cryptomonas phi contains three small chromosomes.


2019 ◽  
Vol 13 (1) ◽  
pp. 90-101
Author(s):  
Sanju Kumari ◽  
Utkarshini Sharma ◽  
Rohit Krishna ◽  
Kanak Sinha ◽  
Santosh Kumar

Background: Cellulolysis is of considerable economic importance in laundry detergents, textile and pulp and paper industries and in fermentation of biomass into biofuels. Objective: The aim was to screen cellulase producing actinobacteria from the fruit orchard because of its requirement in several chemical reactions. Methods: Strains of actinobacteria were isolated on Sabouraud’s agar medium. Similarities in cultural and biochemical characterization by growing the strains on ISP medium and dissimilarities among them perpetuated to recognise nine groups of actinobacteria. Cellulase activity was measured by the diameter of clear zone around colonies on CMC agar and the amount of reducing sugar liberated from carboxymethyl cellulose in the supernatant of the CMC broth. Further, 16S rRNA gene sequencing and molecular characterization were placed before NCBI for obtaining recognition with accession numbers. Results: Prominent clear zones on spraying Congo Red were found around the cultures of strains of three groups SK703, SK706, SK708 on CMC agar plates. The enzyme assay for carboxymethylcellulase displayed extra cellulase activity in broth: 0.14, 0.82 and 0.66 µmol mL-1 min-1, respectively at optimum conditions of 35°C, pH 7.3 and 96 h of incubation. However, the specific cellulase activities per 1 mg of protein did not differ that way. It was 1.55, 1.71 and 1.83 μmol mL-1 min-1. The growing mycelia possessed short compact chains of 10-20 conidia on aerial branches. These morphological and biochemical characteristics, followed by their verification by Bergey’s Manual, categorically allowed the strains to be placed under actinobacteria. Further, 16S rRNA gene sequencing, molecular characterization and their evolutionary relationship through phylogenetics also confirmed the putative cellulase producing isolates of SK706 and SK708 subgroups to be the strains of Streptomyces. These strains on getting NCBI recognition were christened as Streptomyces glaucescens strain SK91L (KF527284) and Streptomyces rochei strain SK78L (KF515951), respectively. Conclusion: Conclusive evidence on the basis of different parameters established the presence of cellulase producing actinobacteria in the litchi orchard which can convert cellulose into fermentable sugar.


LWT ◽  
2021 ◽  
Vol 147 ◽  
pp. 111579
Author(s):  
Creciana M. Endres ◽  
Ícaro Maia S. Castro ◽  
Laura D. Trevisol ◽  
Juliana M. Severo ◽  
Michele B. Mann ◽  
...  

2019 ◽  
Vol 43 (1) ◽  
Author(s):  
Gilsang Jeong ◽  
Taeman Han ◽  
Haechul Park ◽  
Soyeon Park ◽  
Pureum Noh

Abstract Background Wolbachia are among the most prevalent endosymbiotic bacteria and induce reproductive anomalies in various invertebrate taxa. The bacterium has huge impacts on host reproductive biology, immunity, evolution, and molecular machinery. However, broad-scale surveys of Wolbachia infections at the order scale, including the order Coleoptera, are limited. In this study, we investigated the Wolbachia infection frequency in 201 Coleopteran insects collected in Korea. Results A total of 26 species (12.8%) belonging to 11 families harbored Wolbachia. The phylogenetic trees of based on partial 16S rRNA gene sequences and partial Wolbachia surface protein (wsp) gene sequences were largely incongruent to that of their hosts. This result confirms that Wolbachia evolved independently from their hosts, Conclusion Phylogenetic trees suggest that complex horizontal gene transfer and recombination events occurred within and between divergent Wolbachia subgroups.


2013 ◽  
Vol 85 (1) ◽  
pp. 147-157 ◽  
Author(s):  
Saulo M. Sousa ◽  
Patrícia M.O. Pierre ◽  
Giovana A. Torres ◽  
Lisete C. Davide ◽  
Lyderson F. Viccini

The pollen morphology and exine structure of 17 species of Lippia L. were investigated in this work using light and scanning electron microscopy. Among the species studied, 14 showed tricolporate pollen grains, two had tri- and tetracolporate pollen grains and a single species exhibited, only tetracolporate pollen. The amb ranged from triangular to square, and the shape varied from oblate-spheroidal to prolate-spheroidal. Three different types of exine ornamentation were observed: psilate, scabrate and perforate. In addition to morphological data, we found positive association between the chromosome numbers and size of pollen grains, and also between the length and width of the colpi. The results indicate that the characteristics of pollen grains in Lippia may be used as an additional taxonomic character of the genus.


2004 ◽  
Vol 54 (6) ◽  
pp. 2369-2373 ◽  
Author(s):  
Geoffrey Foster ◽  
Barry Holmes ◽  
Arnold G. Steigerwalt ◽  
Paul A. Lawson ◽  
Petra Thorne ◽  
...  

Phenotypic and phylogenetic studies were performed on four Campylobacter-like organisms recovered from three seals and a porpoise. Comparative 16S rRNA gene sequencing studies demonstrated that the organisms represent a hitherto unknown subline within the genus Campylobacter, associated with a subcluster containing Campylobacter jejuni, Campylobacter coli and Campylobacter lari. DNA–DNA hybridization studies confirmed that the bacteria belonged to a single species, for which the name Campylobacter insulaenigrae sp. nov. is proposed. The type strain of Campylobacter insulaenigrae sp. nov. is NCTC 12927T (=CCUG 48653T).


2006 ◽  
Vol 56 (2) ◽  
pp. 413-416 ◽  
Author(s):  
Sabri M. Naser ◽  
Marc Vancanneyt ◽  
Bart Hoste ◽  
Cindy Snauwaert ◽  
Katrien Vandemeulebroecke ◽  
...  

The taxonomic relatedness between the species Enterococcus casseliflavus and Enterococcus flavescens and between Enterococcus italicus and Enterococcus saccharominimus was investigated. Literature data had already indicated the synonymy between E. casseliflavus and E. flavescens, but this observation had not been formally published. Additional evidence that the two taxa represent a single species was provided by comparison of the partial sequences for three housekeeping genes, phenylalanyl-tRNA synthase alpha subunit (pheS), RNA polymerase alpha subunit (rpoA) and the alpha subunit of ATP synthase (atpA). Additional genomic data derived from DNA–DNA hybridization demonstrated that the two species are synonymous. For E. italicus and E. saccharominimus, two recently described taxa, a high 16S rRNA gene sequence similarity of >99 % and analogous phenotypic features indicated a close taxonomic relatedness. The same multilocus sequence analysis scheme for the three housekeeping genes was also applied for E. italicus and E. saccharominimus and indicated possible conspecificity, an observation that was also confirmed by a high DNA–DNA hybridization value (⩾78 %). Data from the present study led to the proposal that E. flavescens should be reclassified as a later synonym of E. casseliflavus and that E. saccharominimus should be reclassified as a later synonym of E. italicus.


2020 ◽  
Vol 57 (2) ◽  
pp. 179-184
Author(s):  
P. F. Barradas ◽  
A. R. Flores ◽  
T. L. Mateus ◽  
F. Carvalho ◽  
F. Gärtner ◽  
...  

SummaryCrenosoma striatum is a host-specifi c metastrongiloid nematode causing respiratory tract disease in hedgehogs (Erinaceus europaeus). Since few studies have reported C. striatum in hedgehogs and little genetic data is available concerning this lungworm, this study aimed to determine the occurrence of C. striatum in a population sample of hedgehogs from Portugal, additionally providing morphological, histological and molecular data. From 2017 to 2018 a survey of infection was carried out in 11 necropsied hedgehogs. Worms were extracted from fresh lung tissues and microscopically evaluated. Molecular characterization of partial mitochondrial (12S rRNA) and nuclear (18S rRNA) genes was performed. The presence of lungworms in pulmonary tissues of five hedgehogs (45.5%) was detected. Morphological and histopathological analyses evidenced adult forms of nematodes consistent with C. striatum. Molecular characterization of 18S rRNA genes confirmed the classifi cation as C. striatum. Also, novel genetic data characterizing the mitochondrial (12S rRNA) gene of C. striatum is presented.This is the first report of C. striatum infection in hedgehogs of Portugal. The findings here reported provide new insights regarding the geographic distribution and the molecular identification of this lungworm species.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Jasem Saki ◽  
Masoud Foroutan-Rad ◽  
Reza Asadpouri

Background. Rodents could act as reservoir forCryptosporidiumspp. speciallyC. parvum, a zoonotic agent responsible for human infections. Since there is no information aboutCryptosporidiuminfection in rodents of Ahvaz city, southwest of Iran, hence, this survey was performed to determine the prevalence and molecular characterization ofCryptosporidiumspp. in this region.Materials and Methods. One hundred rodents were trapped from different regions of Ahvaz city. Intestine contents and fecal specimens of rodents were studied using both microscopy examination to identify oocyst and nested-polymerase chain reaction (PCR) technique for 18s rRNA gene detection. Eventually restriction fragment length polymorphism (RFLP) method usingSspIandVspIrestriction enzymes was carried out to genotype the species and then obtained results were sequenced.Results. Three out of 100 samples were diagnosed as positive and overall prevalence ofCryptosporidiumspp. was 3% using both modified Ziehl-Neelsen staining under light microscope and nested-PCR (830 bp) methods. Afterwards, PCR-RFLP was performed on positive samples andC. parvumpattern was identified. Finally PCR-RFLP findings were sequenced and presence ofC. parvumwas confirmed again.Conclusions. Our study showed rodents could be potential reservoir forC. parvum. So an integrated program for control and combat with them should be adopted and continued.


1995 ◽  
Vol 347 (1320) ◽  
pp. 213-234 ◽  

Phylogenedc reladonships of higher taxa of echinoids have been invesdgated using a 163 character morphological data base and molecular sequences from large and small subunit (LSU and SSU) ribosomal RNA (rRNA) genes. The complete ssu rRNA gene has been sequenced for 21 taxa, with representatives from nine of the 14 extant orders of Echinoidea. Partial LSU sequences, representing the first 400 base pairs (b.p.) from the 5' end were also sequenced for three taxa to complement an existing data base of ten taxa. The two molecular sequences provided a total of 371 variable sites, of which 143 were phylogenetically informative (compared to 145 phylogenetically informative sites from morphological data). Morphological, LSU and SSU data have been analysed separately and together. Morphological and ssu sequence data generate topologies that are not significantly in conflict (under Templeton’s test), but the strong signal pairing arbaciids with clypeasteroids in the LSU derived tree marks the LSU sequence data as anomalous for this taxon. A ‘ total evidence’ approach derived a tree very similar in topology to that derived from morphological data. Rooted on the stem group echinoid Archaeocidaris , our total evidence tree suggested relationships of higher taxa as follows: Gidaroida Phormosomatidae Echinothuriidae Diadematidae Spatangoida Clypeasteroida, Cassiduloida Calycina, Arbacioida Stomopneustidae Glyphocidaridae Temnopleuridae Echinometridae Echinidae, Strongylocentridae. Phylogenetic analyses run both with and without key fossil taxa yielded slightly different topologies. It is important to include fossil taxa in a phylogenetic analysis where there are long stem-group branches or where the crown group is highly derived.


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