M-sequence
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Hantavirus carried by the European common vole Microtus arvalis from Moravia (Czech Republic) was analyzed by RT-PCR-sequencing and by reactivity with a panel of monoclonal antibodies (MAbs). Sequencing of the full-length S segment and the proximal part of the M segment showed that the virus belonged to genotype Tula (TUL) we discovered earlier in Microtus arvalis from Central Russia. This finding supported the concept of host dependence of hantaviruses. Phylogenetic analyses suggested a similar evolutionary history for S and M genes of TUL strains; thus far there is no evidence for reassortment in TUL. Geographic clustering of TUL genetic variants was observed and different levels of the genetic variability were revealed resembling those estimated for another hantavirus, Puumala (PUU). Comparison of the deduced N protein sequence from Russia and from Moravia showed that genetic drift in TUL occurred not only by accumulation of point mutations but also by the deletion of a nucleotide triplet. It encoded Ser252 which was located within a highly variable hydrophilic part of the N protein carrying B-cell epitopes and presumably forming a loop. Analysis of naturally expressed TUL N-antigen derived from lung tissue of infected voles with MAbs indicated antigenic heterogeneity among TUL strains.
- MeSH
- antigeny virové imunologie MeSH
- Arvicolinae virologie MeSH
- DNA virů MeSH
- fylogeneze MeSH
- genetická variace MeSH
- Hantavirus klasifikace genetika imunologie MeSH
- králíci MeSH
- molekulární sekvence - údaje MeSH
- monoklonální protilátky imunologie MeSH
- nukleokapsida imunologie MeSH
- protilátky virové imunologie MeSH
- RNA virová * MeSH
- sekvence aminokyselin MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza MeSH
- virové proteiny MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
The antigenicity, structural location, and function of the predicted lipoprotein TP0136 of Treponema pallidum subsp. pallidum were investigated based on previous screening studies indicating that anti-TP0136 antibodies are present in the sera of syphilis patients and experimentally infected rabbits. Recombinant TP0136 (rTP0136) protein was purified and shown to be strongly antigenic during human and experimental rabbit infection. The TP0136 protein was exposed on the surface of the bacterial outer membrane and bound to the host extracellular matrix glycoproteins fibronectin and laminin. In addition, the TP0136 open reading frame was shown to be highly polymorphic among T. pallidum subspecies and strains at the nucleotide and amino acid levels. Finally, the ability of rTP0136 protein to act as a protective antigen to subsequent challenge with infectious T. pallidum in the rabbit model of infection was assessed. Immunization with rTP0136 delayed ulceration but did not prevent infection or the formation of lesions. These results demonstrate that TP0136 is expressed on the outer membrane of the treponeme during infection and may be involved in attachment to host extracellular matrix components.
- MeSH
- bakteriální vakcíny MeSH
- DNA bakterií genetika chemie MeSH
- fibronektiny * metabolismus MeSH
- fluorescenční mikroskopie MeSH
- imunoelektronová mikroskopie MeSH
- králíci MeSH
- laminin * metabolismus MeSH
- lidé MeSH
- molekulární sekvence - údaje MeSH
- polymorfismus genetický MeSH
- proteiny vnější bakteriální membrány genetika imunologie izolace a purifikace metabolismus MeSH
- protilátky bakteriální genetika imunologie izolace a purifikace krev metabolismus MeSH
- rekombinantní proteiny imunologie MeSH
- Treponema pallidum * MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Escherichia coli sequence type 131 (ST131) is currently one of the leading causes of multidrug-resistant extraintestinal infections globally. Here, we analyzed the phenotypic and genotypic characteristics of 169 ST131 isolates from various sources (wildlife, wastewater, companion animals, community, and hospitals) to determine whether wildlife and the environment share similar strains with humans, supporting transmission of ST131 between different ecological niches. Susceptibility to 32 antimicrobials was tested by disc diffusion and broth microdilution. Antibiotic resistance genes, integrons, plasmid replicons, 52 virulence genes, and fimH-based subtypes were detected by PCR and DNA sequencing. Genomic relatedness was determined by pulsed-field gel electrophoresis (PFGE). The genetic context and plasmid versus chromosomal location of extended-spectrum beta-lactamase and AmpC beta-lactamase genes was determined by PCR and probe hybridization, respectively. The 169 ST131 study isolates segregated predominantly into blaCTX-M-15H30Rx (60%) and blaCTX-M-27H30R1 (25%) subclones. Within each subclone, isolates from different source groups were categorized into distinct PFGE clusters; genotypic characteristics were fairly well conserved within each major PFGE cluster. Irrespective of source, the blaCTX-M-15H30Rx isolates typically exhibited virotype A (89%), an F2:A1:B- replicon (84%), and a 1.7-kb class 1 integron (92%) and had diverse structures upstream of the blaCTX-M region. In contrast, the blaCTX-M-27H30R1 isolates typically exhibited virotype C (86%), an F1:A2:B20 replicon (76%), and a conserved IS26-ΔISEcp1-blaCTX-M-like structure. Despite considerable overall genetic diversity, our data demonstrate significant commonality between E. coli ST131 isolates from diverse environments, supporting transmission between different sources, including humans, environment, and wildlife.
- MeSH
- antibakteriální látky farmakologie MeSH
- beta-laktamasy genetika MeSH
- Escherichia coli účinky léků genetika MeSH
- infekce vyvolané Escherichia coli genetika mikrobiologie MeSH
- infekce získané v komunitě genetika mikrobiologie MeSH
- lidé MeSH
- mnohočetná bakteriální léková rezistence genetika MeSH
- plazmidy genetika MeSH
- proteiny z Escherichia coli genetika MeSH
- pulzní gelová elektroforéza MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Sexual reproduction and clonality in eukaryotes are mostly seen as exclusive, the latter being rather exceptional. This view might be biased by focusing almost exclusively on metazoans. We analyze and discuss reproduction in the context of extant eukaryotic diversity, paying special attention to protists. We present results of phylogenetically extended searches for homologs of two proteins functioning in cell and nuclear fusion, respectively (HAP2 and GEX1), providing indirect evidence for these processes in several eukaryotic lineages where sex has not been observed yet. We argue that (i) the debate on the relative significance of sex and clonality in eukaryotes is confounded by not appropriately distinguishing multicellular and unicellular organisms; (ii) eukaryotic sex is extremely widespread and already present in the last eukaryotic common ancestor; and (iii) the general mode of existence of eukaryotes is best described by clonally propagating cell lines with episodic sex triggered by external or internal clues. However, important questions concern the relative longevity of true clonal species (i.e., species not able to return to sexual procreation anymore). Long-lived clonal species seem strikingly rare. We analyze their properties in the light of meiotic sex development from existing prokaryotic repair mechanisms. Based on these considerations, we speculate that eukaryotic sex likely developed as a cellular survival strategy, possibly in the context of internal reactive oxygen species stress generated by a (proto) mitochondrion. Thus, in the context of the symbiogenic model of eukaryotic origin, sex might directly result from the very evolutionary mode by which eukaryotic cells arose.
- MeSH
- eukaryotické buňky fyziologie MeSH
- fúze buněk MeSH
- genom MeSH
- meióza MeSH
- mitochondrie metabolismus MeSH
- molekulární sekvence - údaje MeSH
- reaktivní formy kyslíku metabolismus MeSH
- rozmnožování * MeSH
- sekvenční analýza DNA MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
UNLABELLED: How bacteria control proper septum placement at midcell, to guarantee the generation of identical daughter cells, is still largely unknown. Although different systems involved in the selection of the division site have been described in selected species, these do not appear to be widely conserved. Here, we report that LocZ (Spr0334), a newly identified cell division protein, is involved in proper septum placement in Streptococcus pneumoniae. We show that locZ is not essential but that its deletion results in cell division defects and shape deformation, causing cells to divide asymmetrically and generate unequally sized, occasionally anucleated, daughter cells. LocZ has a unique localization profile. It arrives early at midcell, before FtsZ and FtsA, and leaves the septum early, apparently moving along with the equatorial rings that mark the future division sites. Consistently, cells lacking LocZ also show misplacement of the Z-ring, suggesting that it could act as a positive regulator to determine septum placement. LocZ was identified as a substrate of the Ser/Thr protein kinase StkP, which regulates cell division in S. pneumoniae. Interestingly, homologues of LocZ are found only in streptococci, lactococci, and enterococci, indicating that this close phylogenetically related group of bacteria evolved a specific solution to spatially regulate cell division. IMPORTANCE: Bacterial cell division is a highly ordered process regulated in time and space. Recently, we reported that the Ser/Thr protein kinase StkP regulates cell division in Streptococcus pneumoniae, through phosphorylation of several key proteins. Here, we characterized one of the StkP substrates, Spr0334, which we named LocZ. We show that LocZ is a new cell division protein important for proper septum placement and likely functions as a marker of the cell division site. Consistently, LocZ supports proper Z-ring positioning at midcell. LocZ is conserved only among streptococci, lactococci, and enterococci, which lack homologues of the Min and nucleoid occlusion effectors, indicating that these bacteria adapted a unique mechanism to find their middle, reflecting their specific shape and symmetry.
- MeSH
- buněčné dělení * MeSH
- delece genu MeSH
- Enterococcus genetika MeSH
- Lactococcus genetika MeSH
- proteiny buněčného cyklu genetika metabolismus MeSH
- sekvenční homologie aminokyselin MeSH
- Streptococcus pneumoniae cytologie genetika fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Encephalitozoon cuniculi is a model microsporidian species with a mononucleate nucleus and a genome that has been extensively studied. To date, analyses of genome diversity have revealed the existence of four genotypes in E. cuniculi (EcI, II, III and IV). Genome sequences are available for EcI, II and III, and are all very divergent, possibly diploid and genetically homogeneous. The mechanisms that cause low genetic diversity in E. cuniculi (for example, selfing, inbreeding or a combination of both), as well as the degree of genetic variation in their natural populations, have been hard to assess because genome data have been so far gathered from laboratory-propagated strains. In this study, we aim to tackle this issue by analyzing the complete genome sequence of a natural strain of E. cuniculi isolated in 2013 from a steppe lemming. The strain belongs to the EcIII genotype and has been designated EcIII-L. The EcIII-L genome sequence harbors genomic features intermediate to known genomes of II and III lab strains, and we provide primers that differentiate the three E. cuniculi genotypes using a single PCR. Surprisingly, the EcIII-L genome is also highly homogeneous, harbors signatures of heterozygosity and also one strain-specific single-nucleotide polymorphism (SNP) that introduces a stop codon in a key meiosis gene, Spo11. Functional analyses using a heterologous system demonstrate that this SNP leads to a deficient meiosis in a model fungus. This indicates that EcIII-L meiotic machinery may be presently broken. Overall, our findings reveal previously unsuspected genome diversity in E. cuniculi, some of which appears to affect genes of primary importance for the biology of this pathogen.
- MeSH
- Arvicolinae mikrobiologie MeSH
- DNA fungální genetika MeSH
- Encephalitozoon cuniculi genetika MeSH
- genetická variace * MeSH
- genom fungální * MeSH
- genotyp MeSH
- heterozygot MeSH
- jednonukleotidový polymorfismus MeSH
- mapování chromozomů MeSH
- meióza MeSH
- sekvenční analýza DNA MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The parabasalid protist Trichomonas vaginalis is a widespread parasite that affects humans, frequently causing vaginitis in infected women. Trichomonad mitosis is marked by the persistence of the nuclear membrane and the presence of an asymmetric extranuclear spindle with no obvious direct connection to the chromosomes. No centromeric markers have been described in T. vaginalis, which has prevented a detailed analysis of mitotic events in this organism. In other eukaryotes, nucleosomes of centromeric chromatin contain the histone H3 variant CenH3. The principal aim of this work was to identify a CenH3 homolog in T. vaginalis. We performed a screen of the T. vaginalis genome to retrieve sequences of canonical and variant H3 histones. Three variant histone H3 proteins were identified, and the subcellular localization of their epitope-tagged variants was determined. The localization of the variant TVAG_185390 could not be distinguished from that of the canonical H3 histone. The sequence of the variant TVAG_087830 closely resembled that of histone H3. The tagged protein colocalized with sites of active transcription, indicating that the variant TVAG_087830 represented H3.3 in T. vaginalis. The third H3 variant (TVAG_224460) was localized to 6 or 12 distinct spots at the periphery of the nucleus, corresponding to the number of chromosomes in G(1) phase and G(2) phase, respectively. We propose that this variant represents the centromeric marker CenH3 and thus can be employed as a tool to study mitosis in T. vaginalis. Furthermore, we suggest that the peripheral distribution of CenH3 within the nucleus results from the association of centromeres with the nuclear envelope throughout the cell cycle.
- MeSH
- aktivace transkripce MeSH
- buněčné jádro genetika metabolismus MeSH
- centromera genetika metabolismus MeSH
- chromozomy genetika metabolismus MeSH
- fluorescenční mikroskopie MeSH
- G1 fáze MeSH
- G2 fáze MeSH
- genom protozoální MeSH
- histony genetika metabolismus MeSH
- jaderný obal metabolismus MeSH
- mitóza MeSH
- molekulární sekvence - údaje MeSH
- nukleozomy metabolismus MeSH
- protozoální proteiny genetika metabolismus MeSH
- sekvence aminokyselin MeSH
- sekvenční analýza proteinů MeSH
- transformace genetická MeSH
- Trichomonas vaginalis genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Previous reports from this laboratory have shown marked cytocidal effects of the ISIS-3466 antisense phosphorothioate oligodeoxynucleotide to the human nucleolar protein p120 on human cancer cell lines in vitro and inhibition of tumor growth in vivo in an i.p/i.p. LOX cell model (L. Perlaky et al. Anti-Cancer Drug Design 8:3-14, 1993). In this study, light and fluorescence microscopy showed that the number of LOX cells in mitosis decreased by 50% after incubation for 4 h in 0.2-0.4 microM antisense oligonucleotide; a 70% reduction in cell number was found from 8-72 h post-treatment. In addition, marked unravelling of nucleolar structures and chromatin fragmentation was found after a 4-h incubation. The nucleolar unravelling occurred in varying degrees ranging from partial unfolding to almost complete separation of the strands of nucleolar residues. Twenty four hours post-treatment, immunofluorescence staining with the anti-p120 monoclonal antibody showed reduced nucleolar protein p120 and translocation of the p120 protein from the nucleoli to the nucleoplasm. Analysis of the mechanisms of the nucleolar unravelling and inhibition of mitosis will provide further understanding of the cytocidal effects of the ISIS-3466 antisense oligonucleotide.
- MeSH
- amelanotický melanom * genetika chemie patologie MeSH
- antigeny nádorové * účinky léků MeSH
- antisense oligodeoxyribonukleotidy * MeSH
- antisense oligonukleotidy farmakologie genetika MeSH
- buněčné jadérko * účinky léků MeSH
- buněčné jádro účinky léků MeSH
- chromatin účinky léků MeSH
- fluorescenční mikroskopie MeSH
- jaderné proteiny * účinky léků MeSH
- lidé MeSH
- mitóza účinky léků MeSH
- molekulární sekvence - údaje MeSH
- nádorové buňky kultivované účinky léků MeSH
- sekvence nukleotidů MeSH
- thionukleotidy farmakologie genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
