vacuolar morphology Dotaz Zobrazit nápovědu
Membrane proteins are targeted not only to specific membranes in the cell architecture, but also to distinct lateral microdomains within individual membranes to properly execute their biological functions. Yeast tetraspan protein Nce102 has been shown to migrate between such microdomains within the plasma membrane in response to an acute drop in sphingolipid levels. Combining microscopy and biochemistry methods, we show that upon gradual ageing of a yeast culture, when sphingolipid demand increases, Nce102 migrates from the plasma membrane to the vacuole. Instead of being targeted for degradation it localizes to V-ATPase-poor, i.e., ergosterol-enriched, domains of the vacuolar membrane, analogous to its plasma membrane localization. We discovered that, together with its homologue Fhn1, Nce102 modulates vacuolar morphology, dynamics, and physiology. Specifically, the fusing of vacuoles, accompanying a switch of fermenting yeast culture to respiration, is retarded in the strain missing both proteins. Furthermore, the absence of either causes an enlargement of ergosterol-rich vacuolar membrane domains, while the vacuoles themselves become smaller. Our results clearly show decreased stability of the V-ATPase in the absence of either Nce102 or Fhn1, a possible result of the disruption of normal microdomain morphology of the vacuolar membrane. Therefore, the functionality of the vacuole as a whole might be compromised in these cells.
- Klíčová slova
- eisosome, membrane microdomains, sphingolipid metabolism, vacuolar morphology, yeast,
- MeSH
- Saccharomyces cerevisiae - proteiny metabolismus MeSH
- Saccharomyces cerevisiae metabolismus MeSH
- vakuoly metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- NCE102 protein, S cerevisiae MeSH Prohlížeč
- Saccharomyces cerevisiae - proteiny MeSH
The green algae of the genus Ancylonema, which belong to the zygnematophytes, are prevalent colonizers of glaciers worldwide. They display a striking reddish-brown pigmentation in their natural environment, due to vacuolar compounds related to gallic acid. This pigmentation causes glacier darkening when these algae bloom, leading to increased melting rates. The Ancylonema species known so far are true psychrophiles, which hinders experimental work and limits our understanding of these algae. For instance, the biosynthesis, triggering factors, and biological function of Ancylonema's secondary pigments remain unknown. In this study, we introduce a mesophilic Ancylonema species, A. palustre sp. nov., from temperate moorlands. This species forms the sister lineage to all known psychrophilic strains. Despite its morphological similarity to the latter, it exhibits unique autecological and photophysiological characteristics. It allows us to describe vegetative and sexual cellular processes in great detail. We also conducted experimental tests for abiotic factors that induce the secondary pigments of zygnematophytes. We found that low nutrient conditions combined with ultraviolet B radiation result in vacuolar pigmentation, suggesting a sunscreen function. Our thriving, bacteria-free cultures of Ancylonema palustre will enable comparative genomic studies of mesophilic and extremophilic zygnematophytes. These studies may provide insights into how Ancylonema species colonized the world's glaciers.
- MeSH
- biologické pigmenty * metabolismus MeSH
- Chlorophyceae metabolismus genetika MeSH
- Chlorophyta metabolismus genetika MeSH
- fylogeneze * MeSH
- pigmentace MeSH
- vakuoly * metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biologické pigmenty * MeSH
BACKGROUND: Histopathological assessment of kidney prior to transplantation is a part of the comprehensive information gathered on the transplanted organ. In our study we monitor the influence of individual morphological findings (glomeruli, arteries, arterioles, interstitium, tubules) and degree of histopathological changes in the kidney function after transplantation. METHODS: From 1994 to 1997, 117 cadaveric kidneys were histopathologically examined and subsequently transplanted. Biopsy in a form of wedge excision was obtained during the organ procurement after in situ kidney perfusion and its removal from donor's body. Evaluated were glomerulosclerosis, intimal fibrosis of arteries, arteriolar hyalinization, interstitial fibrosis and tubular changes (vacuolar dystrophy of tubular epithelium, desquamation of tubular epithelium, brush border of proximal tubules, tubular dilatation, haemoglobin cylinders in distal tubules). Kidney recipients were monitored both for immediate function of transplanted organ and long-term kidney function for a period of five years following. RESULTS: In our group of patients, no unambiguously negative influence of histopathological change in individual morphologies was found either in the immediate or in the long-term function of the transplanted kidney. CONCLUSION: It is possible to transplant kidneys and attain satisfactory results even with these types of histopathological changes: glomerulosclerosis greater or equal to 20 %, mild degree of arterial lesion, moderate arteriolar lesions, moderate lesions of interstitial fibrosis and tubular lesions. The degree of arterial lesions, arteriolar lesions and the degree of interstitial fibrosis closely correlate to the donor's age, hypertension and nontraumatic cerebrovascular accident as the cause of death. Same outcomes were also confirmed with glomerulosclerosis, with the exception of the influence of the donor's age.
- MeSH
- dárci tkání MeSH
- dítě MeSH
- dospělí MeSH
- ledviny patologie patofyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- odběr tkání a orgánů MeSH
- senioři MeSH
- transplantace ledvin patologie fyziologie MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
We attempted to investigate the clinicopathological correlation of renal oncocytoma (RO) with renal vein extension. We identified seven ROs with extension into the branches of renal vein. The age of seven patients ranged from 61 to 82 years. Five cases were identified; incidentally, two patients had gross hematuria. After surgery, all patients were alive and free of tumors with follow-up of 1 to 5 years (mean=3.6). Oncocytomas measured from 2.2 to 7.5 cm. Renal vein extension was grossly suspected in 5/7 cases and histologically confirmed in all seven cases. Tumor cells were positive for cytokeratins, mitochondrial antigen, epithelial membrane antigen, and parvalbumin; 5/7 tumors were focally positive for cluster of differentiation 117. Ultrastructurally, the cytoplasm was packed by mitochondria. Molecular genetic analysis did not detect abnormal numbers of chromosomes 1, 2, 6, 7, 10, 17, and XY by fluorescence in situ hybridization, loss of heterozygosity on 3p, and mutation of Von Hippel-Lindau gene in all cases. Array comparative genomic hybridization analysis of two cases did not show any major genetic changes. Conclusions are: (1) renal oncocytomas may have intravascular extension to the branches of the renal vein; (2) renal oncocytomas with intravascular extension to the branches of the renal vein have the same morphological, immunohistochemical, and cytogenetic findings as have their counterparts without evidence of intravascular invasion; (3) the absence of metastases suggests an overall benign behavior of this tumor, but this has to be substantiated by further studies with a long-term follow-up; (4) in a renal tumor with granular cytoplasm showing renal vein extension, it is necessary to carefully exclude renal cell carcinomas (RCC) such as chromophobe RCC, oncocytic variant of papillary RCC, and granular variant of clear cell RCC.
- MeSH
- biologické markery analýza MeSH
- diferenciální diagnóza MeSH
- genom lidský MeSH
- hybridizace in situ fluorescenční MeSH
- hybridizace nukleových kyselin MeSH
- imunohistochemie MeSH
- keratiny analýza MeSH
- ledviny krevní zásobení metabolismus patologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mucin 1 analýza MeSH
- mutace MeSH
- nádorový supresorový protein VHL genetika MeSH
- nádory ledvin genetika metabolismus patologie MeSH
- oxyfilní adenom genetika metabolismus patologie MeSH
- parvalbuminy analýza MeSH
- proteiny Caenorhabditis elegans MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- vakuolární protonové ATPasy MeSH
- ztráta heterozygozity MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biologické markery MeSH
- CAM 5.2 antigen MeSH Prohlížeč
- keratiny MeSH
- mucin 1 MeSH
- nádorový supresorový protein VHL MeSH
- parvalbuminy MeSH
- proteiny Caenorhabditis elegans MeSH
- vakuolární protonové ATPasy MeSH
- VHA-5 protein, C elegans MeSH Prohlížeč
- VHL protein, human MeSH Prohlížeč
Cation-Cl(-) cotransporters (CCCs) are integral membrane proteins which catalyze the coordinated symport of Cl(-) with Na(+) and/or K(+) ions in plant and mammalian cells. Here we describe the first Saccharomyces cerevisiae CCC protein, encoded by the YBR235w open reading frame. Subcellular localization studies showed that this yeast CCC is targeted to the vacuolar membrane. Deletion of the YBR235w gene in a salt-sensitive strain (lacking the plasma-membrane cation exporters) resulted in an increased sensitivity to high KCl, altered vacuolar morphology control and decreased survival upon hyperosmotic shock. In addition, deletion of the YBR235w gene in a mutant strain deficient in K(+) uptake produced a significant growth advantage over the parental strain under K(+)-limiting conditions, and a hypersensitivity to the exogenous K(+)/H(+) exchanger nigericin. These results strongly suggest that we have identified a novel yeast vacuolar ion transporter mediating a K(+)-Cl(-) cotransport and playing a role in vacuolar osmoregulation. Considering its identified function, we propose to refer to the yeast YBR235w gene as VHC1 (vacuolar protein homologous to CCC family 1).
- MeSH
- chloridy chemie MeSH
- DNA chemie MeSH
- elektrochemie metody MeSH
- fluorescenční mikroskopie metody MeSH
- fylogeneze MeSH
- genotyp MeSH
- iontový transport MeSH
- kationty chemie MeSH
- koncentrace vodíkových iontů MeSH
- konfokální mikroskopie metody MeSH
- membránové potenciály MeSH
- nigericin farmakologie MeSH
- oligonukleotidy chemie MeSH
- osmotický tlak MeSH
- otevřené čtecí rámce MeSH
- rekombinace genetická MeSH
- Saccharomyces cerevisiae - proteiny chemie fyziologie MeSH
- Saccharomyces cerevisiae metabolismus MeSH
- sorbitol chemie MeSH
- symportéry chemie fyziologie MeSH
- vakuoly chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- chloridy MeSH
- DNA MeSH
- kationty MeSH
- nigericin MeSH
- oligonukleotidy MeSH
- Saccharomyces cerevisiae - proteiny MeSH
- sorbitol MeSH
- symportéry MeSH
- VHC1 protein, S cerevisiae MeSH Prohlížeč
Intracellular protein routing is mediated by vesicular transport which is tightly regulated in eukaryotes. The protein and lipid homeostasis depends on coordinated delivery of de novo synthesized or recycled cargoes to the plasma membrane by exocytosis and their subsequent removal by rerouting them for recycling or degradation. Here, we report the characterization of protein affected trafficking 3 (pat3) mutant that we identified by an epifluorescence-based forward genetic screen for mutants defective in subcellular distribution of Arabidopsis auxin transporter PIN1-GFP. While pat3 displays largely normal plant morphology and development in nutrient-rich conditions, it shows strong ectopic intracellular accumulations of different plasma membrane cargoes in structures that resemble prevacuolar compartments (PVC) with an aberrant morphology. Genetic mapping revealed that pat3 is defective in vacuolar protein sorting 35A (VPS35A), a putative subunit of the retromer complex that mediates retrograde trafficking between the PVC and trans-Golgi network. Similarly, a mutant defective in another retromer subunit, vps29, shows comparable subcellular defects in PVC morphology and protein accumulation. Thus, our data provide evidence that the retromer components VPS35A and VPS29 are essential for normal PVC morphology and normal trafficking of plasma membrane proteins in plants. In addition, we show that, out of the three VPS35 retromer subunits present in Arabidopsis thaliana genome, the VPS35 homolog A plays a prevailing role in trafficking to the lytic vacuole, presenting another level of complexity in the retromer-dependent vacuolar sorting.
- Klíčová slova
- Arabidopsis thaliana., VPS29, VPS35, prevacuolar compartment (PVC), retromer, vacuolar trafficking,
- MeSH
- Arabidopsis genetika fyziologie MeSH
- endocytóza MeSH
- kompartmentace buňky * MeSH
- membránové proteiny metabolismus fyziologie MeSH
- molekulární sekvence - údaje MeSH
- mutace MeSH
- proteiny huseníčku metabolismus fyziologie MeSH
- transport proteinů MeSH
- vakuoly metabolismus MeSH
- vezikulární transportní proteiny metabolismus fyziologie MeSH
- zelené fluorescenční proteiny genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- Mag1 protein, Arabidopsis MeSH Prohlížeč
- membránové proteiny MeSH
- proteiny huseníčku MeSH
- vezikulární transportní proteiny MeSH
- VPS35 protein, Arabidopsis MeSH Prohlížeč
- zelené fluorescenční proteiny MeSH
Ansell's mole-rats (Fukomys anselli) are subterranean rodents living in families composed of about 20 members with a single breeding pair and their non-breeding offspring. Most of them remain with their parents for their lifetime and help to maintain and defend the natal burrow system, forage, and care for younger siblings. Since incest avoidance is based on individual recognition (and not on social suppression) we expect that non-breeders produce viable sperm spontaneously. We compared the sperm of breeding and non-breeding males, obtained by electroejaculation and found no significant differences in sperm parameters between both groups. Here, we used electroejaculation to obtain semen for the first time in a subterranean mammal. Spermiogram analysis revealed no significant differences in sperm parameters between breeders and non-breeders. We found significantly larger testes (measured on autopsies and on living animals per ultrasonography) of breeders compared to non-breeders (with body mass having a significant effect). There were no marked histological differences between breeding and non-breeding males, and the relative area occupied by Leydig cells and seminiferous tubules on histological sections, respectively, was not significantly different between both groups. The seminiferous epithelium and to a lesser degree the interstitial testicular tissue are characterized by lesions (vacuolar degenerations), however, this feature does not hinder fertilization even in advanced stages of life. The continuous production of viable sperm also in sexually abstinent non-breeders might be best understood in light of the mating and social system of Fukomys anselli, and the potential to found a new family following an unpredictable and rare encounter with an unfamiliar female ("provoked or induced dispersal"). Apparently, the non-breeders do not reproduce because they do not copulate but not because they would be physiologically infertile. The significantly increased testes volume of breeding males (compared to non-breeders) is in agreement with previously found higher testosterone levels of breeders.
- MeSH
- chov metody MeSH
- mikroftalmičtí podzemní hlodavci fyziologie MeSH
- rozmnožování fyziologie MeSH
- spermie fyziologie MeSH
- testis fyziologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Over 400 cyanobacterial genera have been described up to the present. Since the Cambridge Rules (https://www.iapt-taxon.org/historic/1935.htm: Rendle 1935), a type species (generitype) must be specified at the time of description for a new genus to be validly described. Even though we have entered a time in which sequencing has become practical and widespread, the basic molecular characterization (e.g., 16S rRNA gene sequence) of most cyanobacterial generitypes is still lacking. About 15 cyanobacterial genera were originally described from Scandinavia. Following a field excursion in which the type or syntype localities for the type species of these genera were visited and sampled, we succeeded in finding three type species from their type or syntype localities: Capsosira brebissonii, Stigonema mamillosum, and Paracapsa siderophila. Epitypes for all three generitypes are herein established. Cells or filaments of C. brebissonii and S. mamillosum were isolated and used for single-cell/filament PCR amplification of the 16S rRNA gene and subsequent cloning and sequencing of the PCR amplicons. This allows a firm establishment of reference sequences of these two genera, to which morphologically similar taxa can now be compared. Stigonema and Capsosira are shown herein to be sister to Aetokthonos hydrillicola, a cyanobacterium known to cause avian vacuolar myelinopathy in birds, including bald eagles.
- Klíčová slova
- Capsosira brebissonii, Paracapsa siderophila, Stigonema mamillosum, 16S rRNA gene, 16S–23S ITS, avian vacuolar myelinopathy, cyanobacteria, generitypes, type locality,
- Publikační typ
- časopisecké články MeSH
A morphological type of Sarcocystis cysts found in one of two examined great black-backed gull, Larus marinus (Linnaeus) (Laridae), is considered to represent a new species for which the name Sarcocystis lari sp. n. is proposed and its description is provided. The cysts are ribbon-shaped, very long (the largest fragment found was 6 mm long) and relatively narrow (up to 75 microm). Under a light microscope the cyst wall reaches up to 1 microm and seems to be smooth. Using a computerized image analysis system, knolls, which resemble protrusions on the wall surface, are visible. Lancet-shaped cystozoites measure in average 6.9 x 1.4 microm (range 6.3-7.9 microm x 1.2-1.5 microm) in length. Observed using Transmission electron microscopy (TEM), the cyst wall is wavy and measures up to 1.2 microm in thickness. The parasitophorous vacuolar membrane has regularly arranged small invaginations. Cyst content is divided into large chambers by septa. Sarcocystis lari sp. n. has type-1 tissue cyst wall and is morphologically indistinguishable from other bird Sarcocystis species characterized by the same type of the wall. On the basis of 18S rRNA gene, 28S rRNA gene and ITS-1 region sequences, S. lari is a genetically distinct species, being most closely related to avian Sarcocystis species whose definitive hosts are predatory birds.
- MeSH
- Charadriiformes MeSH
- fylogeneze MeSH
- kosterní svaly parazitologie MeSH
- nemoci ptáků parazitologie MeSH
- protozoální DNA genetika MeSH
- RNA protozoální genetika MeSH
- RNA ribozomální 18S genetika MeSH
- RNA ribozomální 28S genetika MeSH
- Sarcocystis klasifikace genetika MeSH
- sarkocystóza parazitologie veterinární MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- protozoální DNA MeSH
- RNA protozoální MeSH
- RNA ribozomální 18S MeSH
- RNA ribozomální 28S MeSH
Cyanobacteria are well known producers of bioactive metabolites, including harmful substances. The recently discovered "eagle killer" neurotoxin aetokthonotoxin (AETX) is produced by the epiphytic cyanobacterium Aetokthonos hydrillicola growing on invasive water thyme (Hydrilla verticillata). The biosynthetic gene cluster of AETX was previously identified from an Aetokthonos strain isolated from the J. Strom Thurmond Reservoir, Georgia, USA. Here, a PCR protocol for easy detection of AETX-producers in environmental samples of plant-cyanobacterium consortia was designed and tested. Three different loci of the AETX gene cluster were amplified to confirm the genetic potential for AETX production, along with two variable types of rRNA ITS regions to confirm the homogeneity of the producer´s taxonomic identity. In samples of Hydrilla from three Aetokthonos-positive reservoirs and one Aetokthonos-negative lake, the PCR of all four loci provided results congruent with the Aetokthonos presence/absence detected by light and fluorescence microscopy. The production of AETX in the Aetokthonos-positive samples was confirmed using LC-MS. Intriguingly, in J. Strom Thurmond Reservoir, recently Hydrilla free, an Aetokthonos-like cyanobacterium was found growing on American water-willow (Justicia americana). Those specimens were positive for all three aet markers but contained only minute amounts of AETX. The obtained genetic information (ITS rRNA sequence) and morphology of the novel Aetokthonos distinguished it from all the Hydrilla-hosted A. hydrillicola, likely at the species level. Our results suggest that the toxigenic Aetokthonos spp. can colonize a broader array of aquatic plants, however the level of accumulation of the toxin may be driven by host-specific interactions such as the locally hyper-accumulated bromide in Hydrilla.
- Klíčová slova
- Aetokthonos, Cyanotoxin, Hydrilla, Justicia, Vacuolar myelinopathy, rRNA ITS,
- MeSH
- chromatografie kapalinová MeSH
- hmotnostní spektrometrie MeSH
- jezera * MeSH
- polymerázová řetězová reakce MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- aetokthonotoxin MeSH Prohlížeč