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PloS One 2014Nuclear DNA content in gametophytes and sporophytes or the prostrate phases of the following species of Bonnemaisoniaceae (Asparagopsis armata, Asparagopsis taxiformis,...
Nuclear DNA content in gametophytes and sporophytes or the prostrate phases of the following species of Bonnemaisoniaceae (Asparagopsis armata, Asparagopsis taxiformis, Bonnemaisonia asparagoides, Bonnemaisonia clavata and Bonnemaisonia hamifera) were estimated by image analysis and static microspectrophotometry using the DNA-localizing fluorochrome DAPI (4', 6-diamidino-2-phenylindole, dilactate) and the chicken erythrocytes standard. These estimates expand on the Kew database of DNA nuclear content. DNA content values for 1C nuclei in the gametophytes (spermatia and vegetative cells) range from 0.5 pg to 0.8 pg, and for 2C nuclei in the sporophytes or the prostrate phases range from 1.15-1.7 pg. Although only the 2C and 4C values were observed in the sporophyte or the prostrate phase, in the vegetative cells of the gametophyte the values oscillated from 1C to 4C, showing the possible start of endopolyploidy. The results confirm the alternation of nuclear phases in these Bonnemaisoniaceae species, in those that have tetrasporogenesis, as well as those that have somatic meiosis. The availability of a consensus phylogenetic tree for Bonnemaisoniaceae has opened the way to determine evolutionary trends in DNA contents. Both the estimated genome sizes and the published chromosome numbers for Bonnemaisoniaceae suggest a narrow range of values consistent with the conservation of an ancestral genome.
Topics: Cell Nucleus; DNA, Algal; Genome; Germ Cells, Plant; Life Cycle Stages; Microspectrophotometry; Ploidies; Polyploidy; Rhodophyta
PubMed: 24465835
DOI: 10.1371/journal.pone.0086006 -
World Journal of Gastroenterology Jan 2005To observe the effect of cholecystokinin (CCK) on lipofusin value, neuronal dendrite and spine ultrastructure, and total cellular protein during the process of...
AIM
To observe the effect of cholecystokinin (CCK) on lipofusin value, neuronal dendrite and spine ultrastructure, and total cellular protein during the process of experimental neuronal aging.
METHODS
Experimental neuronal aging study model was established by NBA2 cellular serum-free culture method. By using single intracellular lipofusin value from microspectrophotometry, morphology of neuronal dendrites and spines from the scanner electron microscopy, and total cellular protein as the indexes of experimental neuronal aging, we observed the effect of CCK8 on the process of experimental neuronal aging.
RESULTS
Under the condition of serum-free culture, intracellular fluorescence value (%) increased with the extension of culture time (1 d 8.51+/-3.43; 5 d 10.12+/-3.03; 10 d 20.54+/-10.3; 15 d 36.88+/-10.49; (b)P<0.01). When CCK was added to serum-free culture medium, intracellular lipofusin value (%) decreased remarkably after consecutive CCK reaction for 10 and 15 d (control 36.88+/-10.49; 5 d 32.03+/-10.01; 10 d 14.37+/-5.55; 15 d 17.31+/-4.80; (b)P<0.01). As the time of serum-free culturing was prolonged, the number of neuronal dendrite and spine cells decreased. The later increased in number when CCK8 was added. CCK8 could improve the total cellular protein in the process of experimental neuronal aging.
CONCLUSION
CCK8 may prolong the process of experimental neuronal aging by maintaining the structure and the number of neuronal dendrite and spine cells and changing the total cellular protein.
Topics: Animals; Cell Line, Tumor; Cellular Senescence; Culture Media, Serum-Free; Flow Cytometry; Lipofuscin; Mice; Microscopy, Electron; Microvilli; Neuroblastoma; Neurons; Proteins; Sincalide
PubMed: 15641144
DOI: 10.3748/wjg.v11.i4.551 -
Zoological Letters Nov 2020The dorsal wings of male Sasakia charonda butterflies display a striking blue iridescent coloration, which is accentuated by white, orange-yellow and red spots, as well...
The dorsal wings of male Sasakia charonda butterflies display a striking blue iridescent coloration, which is accentuated by white, orange-yellow and red spots, as well as by brown margins. The ventral wings also have a variegated, but more subdued, pattern. We investigated the optical basis of the various colors of intact wings as well as isolated wing scales by applying light and electron microscopy, imaging scatterometry and (micro)spectrophotometry. The prominent blue iridescence is due to scales with tightly packed, multilayered ridges that contain melanin pigment. The scales in the brown wing margins also contain melanin. Pigments extracted from the orange-yellow and red spots indicate the presence of 3-OH-kynurenine and ommochrome pigment. The scales in the white spots also have multilayered ridges but lack pigment. The lower lamina of the scales plays a so-far undervalued but often crucial role. Its thin-film properties color the majority of the ventral wing scales, which are unpigmented and have large windows. The lower lamina acting as a thin-film reflector generally contributes to the reflectance of the various scale types.
PubMed: 33292721
DOI: 10.1186/s40851-020-00164-6 -
PloS One 2012Caulerpa species are marine green algae, which often act as invasive species with rapid clonal proliferation when growing outside their native biogeographical borders....
Caulerpa species are marine green algae, which often act as invasive species with rapid clonal proliferation when growing outside their native biogeographical borders. Despite many publications on the genetics and ecology of Caulerpa species, their life history and ploidy levels are still to be resolved and are the subject of large controversy. While some authors claimed that the thallus found in nature has a haplodiplobiontic life cycle with heteromorphic alternation of generations, other authors claimed a diploid or haploid life cycle with only one generation involved. DAPI-staining with image analysis and microspectrophotometry were used to estimate relative nuclear DNA contents in three species of Caulerpa from the Mediterranean, at individual, population and species levels. Results show that ploidy levels and genome size vary in these three Caulerpa species, with a reduction in genome size for the invasive ones. Caulerpa species in the Mediterranean are polyploids in different life history phases; all sampled C. taxifolia and C. racemosa var. cylindracea were in haplophasic phase, but in C. prolifera, the native species, individuals were found in both diplophasic and haplophasic phases. Different levels of endopolyploidy were found in both C. prolifera and C. racemosa var. cylindracea. Life history is elucidated for the Mediterranean C. prolifera and it is hypothesized that haplophasic dominance in C. racemosa var. cylindracea and C. taxifolia is a beneficial trait for their invasive strategies.
Topics: Caulerpa; Cytophotometry; DNA, Plant; Flow Cytometry; Genome, Plant; Indoles; Introduced Species; Mediterranean Region; Microspectrophotometry; Polyploidy; Species Specificity
PubMed: 23110095
DOI: 10.1371/journal.pone.0047728 -
Proceedings. Biological Sciences May 2009Animals change their body coloration for a variety of purposes including communication, thermoregulation and crypsis. The cues that trigger adaptive colour change are...
Animals change their body coloration for a variety of purposes including communication, thermoregulation and crypsis. The cues that trigger adaptive colour change are often unclear, and the role of colour vision remains largely untested. Here, we investigated the bluestriped fangblenny (Plagiotremus rhinorhynchos), an aggressive mimic that changes its body coloration to impersonate a variety of coral reef fishes. In this field, we determined the fish species that the fangblenny associated with and measured the spectral reflectance of mimics and their models. We measured the spectral absorbance characteristics of the retinal photoreceptor visual pigments in the bluestriped fangblenny using microspectrophotometry and found it to have rod photoreceptors (lambda(max) 498 nm), single cones (449 nm) and double cones (561 nm principal member; 520 nm accessory member). Using theoretical vision models, fangblennies could discriminate between the colours they adopted and the colours of the fish they associated with. Potential signal receivers (Abudefduf abdominalis and Ctenochaetus strigosus) perceived colours of most mimics to closely resemble fishes they associated with. However, fishes with ultraviolet-sensitive visual pigments were better at discriminating between mimics and models. Therefore, colour vision could be used by fangblennies when initiating colour change enabling them to accurately resemble fishes they associate with and to avoid detection by signal receivers.
Topics: Adaptation, Physiological; Animals; Behavior, Animal; Color; Color Vision; Cues; Perciformes; Photoreceptor Cells, Vertebrate
PubMed: 19324827
DOI: 10.1098/rspb.2008.1819 -
Acta Crystallographica. Section D,... Dec 2013Free-energy landscapes decisively determine the progress of enzymatically catalyzed reactions [Cornish-Bowden (2012), Fundamentals of Enzyme Kinetics, 4th ed.]....
Free-energy landscapes decisively determine the progress of enzymatically catalyzed reactions [Cornish-Bowden (2012), Fundamentals of Enzyme Kinetics, 4th ed.]. Time-resolved macromolecular crystallography unifies transient-state kinetics with structure determination [Moffat (2001), Chem. Rev. 101, 1569-1581; Schmidt et al. (2005), Methods Mol. Biol. 305, 115-154; Schmidt (2008), Ultrashort Laser Pulses in Medicine and Biology] because both can be determined from the same set of X-ray data. Here, it is demonstrated how barriers of activation can be determined solely from five-dimensional crystallography, where in addition to space and time, temperature is a variable as well [Schmidt et al. (2010), Acta Cryst. A66, 198-206]. Directly linking molecular structures with barriers of activation between them allows insight into the structural nature of the barrier to be gained. Comprehensive time series of crystallographic data at 14 different temperature settings were analyzed and the entropy and enthalpy contributions to the barriers of activation were determined. One hundred years after the discovery of X-ray scattering, these results advance X-ray structure determination to a new frontier: the determination of energy landscapes.
Topics: Bacteria; Bacterial Proteins; Crystallography, X-Ray; Kinetics; Photoreceptors, Microbial; Protein Conformation; Thermodynamics
PubMed: 24311594
DOI: 10.1107/S0907444913025997 -
Journal of Dentistry Feb 2013The purpose of this study was to develop an adhesive resin with incorporation of niobium pentoxide and evaluate its properties.
OBJECTIVES
The purpose of this study was to develop an adhesive resin with incorporation of niobium pentoxide and evaluate its properties.
METHODS
Niobium pentoxide was characterised by X-ray diffraction, surface area, particle size, micro-Raman, scanning electron microscopy and the effectiveness of silanisation process by Fourier Transform Infrared (FTIR). An experimental adhesive resin was formulated with 0, 5, 10 and 20wt% Nb(2)O(5). The formulated adhesive resins were evaluated based on microhardness, degree of conversion, radiopacity and interface (resin/dentine) characterisation by micro-Raman.
RESULTS
The particles used in this study presented a monoclinic crystalline phase with typical chemical groups and micrometre mean size. Microhardness and radiopacity increased with higher amounts of Nb(2)O(5), and the particles were able to penetrate into the hybrid layers.
CONCLUSIONS
Therefore, Nb(2)O(5) may be an alternative for polymer-based biomaterials.
CLINICAL SIGNIFICANCE
Niobium pentoxide could be used to produce adhesive resins with enhanced properties.
Topics: Acid Etching, Dental; Animals; Bisphenol A-Glycidyl Methacrylate; Camphor; Cattle; Contrast Media; Crystallography; Dental Bonding; Dentin; Hardness; Methacrylates; Microscopy, Electron, Scanning; Microspectrophotometry; Niobium; Oxides; Particle Size; Polyethylene Glycols; Polymerization; Polymethacrylic Acids; Refractometry; Resin Cements; Silanes; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Raman; Surface Properties; Temperature; Time Factors; X-Ray Diffraction; para-Aminobenzoates
PubMed: 22564371
DOI: 10.1016/j.jdent.2012.04.022 -
The Journal of Physiology May 2012When a substantial fraction of rhodopsin in a rod photoreceptor is exposed to bright light, the rod is desensitized by a process known as bleaching adaptation....
When a substantial fraction of rhodopsin in a rod photoreceptor is exposed to bright light, the rod is desensitized by a process known as bleaching adaptation. Experiments on isolated photoreceptors in amphibians have revealed many of the features of bleaching adaptation, but such experiments have not so far been possible in mammals. We now describe a method for making microspectrophotometric measurements of pigment concentration and suction-electrode recording of electrical responses over a wide range of bleaching exposures from isolated mouse rods or pieces of mouse retina. We show that if pigment is bleached at a low rate in the presence of bovine serum albumin (BSA), and intermediate photoproducts are allowed to decay, mouse rods are stably desensitized; subsequent treatment with exogenous 11-cis retinal results in pigment regeneration and substantial recovery of sensitivity to the dark-adapted value. Stably bleached wild-type (WT) rods show a decrease in circulating current and acceleration of the time course of decay, much as in steady background light; similar effects are seen in guanylyl cyclase-activating protein knockout (GCAPs(-/-)) rods, indicating that regulation of guanylyl cyclase is not necessary for at least a part of the adaptation produced by bleaching. Our experiments demonstrate that in mammalian rods, as in amphibian rods, steady-state desensitization after bleaching is produced by two components: (1) a reduction in the probability of photon absorption produced by a decrease in rhodopsin concentration; and (2) an equivalent background light whose intensity is proportional to the fraction of bleached pigment, and which adapts the rod like real background light. These two mechanisms together fully account for the ‘log-linear' relationship in mammalian retina between sensitivity and per cent bleach, which can be measured in the steady state following exposure to bright light. Our methods will now make possible an examination of bleaching adaptation and pigment regeneration in mouse animal lines with mutations or other alterations in the proteins of transduction.
Topics: Adaptation, Ocular; Animals; Electrodes; Guanylate Cyclase-Activating Proteins; Light; Mice; Mice, Inbred C57BL; Mice, Knockout; Microspectrophotometry; Retinal Rod Photoreceptor Cells
PubMed: 22451436
DOI: 10.1113/jphysiol.2012.228627 -
Vision Research Feb 2007Photoreceptors of nocturnal geckos are transmuted cones that acquired rod morphological and physiological properties but retained cone-type phototransduction proteins....
Photoreceptors of nocturnal geckos are transmuted cones that acquired rod morphological and physiological properties but retained cone-type phototransduction proteins. We have used microspectrophotometry and microfluorometry of solitary isolated green-sensitive photoreceptors of Tokay gecko to study the initial stages of the visual cycle within these cells. These stages are the photolysis of the visual pigment, the reduction of all-trans retinal to all-trans retinol, and the clearance of all-trans retinol from the outer segment (OS) into the interphotoreceptor space. We show that the rates of decay of metaproducts (all-trans retinal release) and retinal-to-retinol reduction are intermediate between those of typical rods and cones. Clearance of retinol from the OS proceeds at a rate that is typical of rods and is greatly accelerated by exposure to interphotoreceptor retinoid-binding protein, IRBP. The rate of retinal release from metaproducts is independent of the position within the OS, while its conversion to retinol is strongly spatially non-uniform, being the fastest at the OS base and slowest at the tip. This spatial gradient of retinol production is abolished by dialysis of saponin-permeabilized OSs with exogenous NADPH or substrates for its production by the hexose monophosphate pathway (NADP+glucose-6-phosphate or 6-phosphogluconate, glucose-6-phosphate alone). Following dialysis by these agents, retinol production is accelerated by several-fold compared to the fastest rates observed in intact cells in standard Ringer solution. We propose that the speed of retinol production is set by the availability of NADPH which in turn depends on ATP supply within the outer segment. We also suggest that principal source of this ATP is from mitochondria located within the ellipsoid region of the inner segment.
Topics: Animals; Dark Adaptation; Eye Proteins; Lizards; Microspectrophotometry; NADP; Photic Stimulation; Photolysis; Photoreceptor Cells, Vertebrate; Retinal Pigments; Retinol-Binding Proteins; Rhodopsin; Tissue Culture Techniques; Vitamin A
PubMed: 17049961
DOI: 10.1016/j.visres.2006.08.024 -
ChemMedChem Jul 2014Cystalysin from Treponema denticola is a pyridoxal 5'-phosphate dependent lyase that catalyzes the formation of pyruvate, ammonia, and sulfide from cysteine. It is a...
Cystalysin from Treponema denticola is a pyridoxal 5'-phosphate dependent lyase that catalyzes the formation of pyruvate, ammonia, and sulfide from cysteine. It is a virulence factor in adult periodontitis because its reaction contributes to hemolysis, which sustains the pathogen. Therefore, it was proposed as a potential antimicrobial target. To identify specific inhibitors by structure-based in silico methods, we first validated the crystal structure of cystalysin as a reliable starting point for the design of ligands. By using single-crystal absorption microspectrophotometry, we found that the enzyme in the crystalline state, with respect to that in solution, exhibits: 1) the same absorption spectra for the catalytic intermediates, 2) a close pKa value for the residue controlling the keto enamine ionization, and 3) similar reactivity with glycine, L-serine, L-methionine, and the nonspecific irreversible inhibitor aminoethoxyvinylglycine. Next, we screened in silico a library of 9357 compounds with the Fingerprints for Ligands and Proteins (FLAP) software, by using the three-dimensional structure of cystalysin as a template. From the library, 17 compounds were selected and experimentally evaluated by enzyme assays and spectroscopic methods. Two compounds were found to competitively inhibit recombinant T. denticola cystalysin, with inhibition constant (Ki ) values of 25 and 37 μM. One of them exhibited a minimum inhibitory concentration (MIC) value of 64 μg mL(-1) on Moraxella catarrhalis ATCC 23246, which proves its ability to cross bacterial membranes.
Topics: Anti-Bacterial Agents; Binding Sites; Catalytic Domain; Cystathionine gamma-Lyase; Enzyme Inhibitors; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Microbial Sensitivity Tests; Molecular Docking Simulation; Periodontitis; Recombinant Proteins; Small Molecule Libraries; Treponema denticola
PubMed: 24616267
DOI: 10.1002/cmdc.201300527