The structure of chromatophores from purple photosynthetic bacteria fused with lipid-impregnated collodion films determined by near-field scanning optical microscopy. (1/166)Lipid-impregnated collodion (nitrocellulose) films have been frequently used as a fusion substrate in the measurement and analysis of electrogenic activity in biological membranes and proteoliposomes. While the method of fusion of biological membranes or proteoliposomes with such films has found a wide application, little is known about the structures formed after the fusion. Yet, knowledge of this structure is important for the interpretation of the measured electric potential. To characterize structures formed after fusion of membrane vesicles (chromatophores) from the purple bacterium Rhodobacter sphaeroides with lipid-impregnated collodion films, we used near-field scanning optical microscopy. It is shown here that structures formed from chromatophores on the collodion film can be distinguished from the lipid-impregnated background by measuring the fluorescence originating either from endogenous fluorophores of the chromatophores or from fluorescent dyes trapped inside the chromatophores. The structures formed after fusion of chromatophores to the collodion film look like isolated (or sometimes aggregated, depending on the conditions) blisters, with diameters ranging from 0.3 to 10 microm (average approximately 1 microm) and heights from 0.01 to 1 microm (average approximately 0.03 microm). These large sizes indicate that the blisters are formed by the fusion of many chromatophores. Results with dyes trapped inside chromatophores reveal that chromatophores fused with lipid-impregnated films retain a distinct internal water phase. (+info)
Escape probability and trapping mechanism in purple bacteria: revisited. (2/166)Despite intensive research for decades, the trapping mechanism in the core complex of purple bacteria is still under discussion. In this article, it is attempted to derive a conceptionally simple model that is consistent with all basic experimental observations and that allows definite conclusions on the trapping mechanism. Some experimental data reported in the literature are conflicting or incomplete. Therefore we repeated two already published experiments like the time-resolved fluorescence decay in LH1-only purple bacteria Rhodospirillum rubrum and Rhodopseudomonas viridis chromatophores with open and closed (Q(A)(-)) reaction centers. Furthermore, we measured fluorescence excitation spectra for both species under the two redox-conditions. These data, all measured at room temperature, were analyzed by a target analysis based on a three-state model (antenna, primary donor, and radical pair). All states were allowed to react reversibly and their decay channels were taken into consideration. This leads to seven rate constants to be determined. It turns out that a unique set of numerical values of these rate constants can be found, when further experimental constraints are met simultaneously, i.e. the ratio of the fluorescence yields in the open and closed (Q(A)(-)) states F(m)/F(o) approximately 2 and the P(+)H(-)-recombination kinetics of 3-6 ns. The model allows to define and to quantify escape probabilities and the transfer equilibrium. We conclude that trapping in LH1-only purple bacteria is largely transfer-to-the-trap-limited. Furthermore, the model predicts properties of the reaction center (RC) in its native LH1-environment. Within the framework of our model, the predicted P(+)H(-)-recombination kinetics are nearly indistinguishable for a hypothetically isolated RC and an antenna-RC complex, which is in contrast to published experimental data for physically isolated RCs. Therefore RC preparations may display modified kinetic properties. (+info)
Reduction and protonation of the secondary quinone acceptor of Rhodobacter sphaeroides photosynthetic reaction center: kinetic model based on a comparison of wild-type chromatophores with mutants carrying Arg-->Ile substitution at sites 207 and 217 in the L-subunit. (3/166)After the light-induced charge separation in the photosynthetic reaction center (RC) of Rhodobacter sphaeroides, the electron reaches, via the tightly bound ubiquinone QA, the loosely bound ubiquinone Q(B) After two subsequent flashes of light, Q(B) is reduced to ubiquinol Q(B)H2, with a semiquinone anion Q-(B) formed as an intermediate after the first flash. We studied Q(B)H2 formation in chromatophores from Rb. sphaeroides mutants that carried Arg-->Ile substitution at sites 207 and 217 in the L-subunit. While Arg-L207 is 17 A away from Q(B), Arg-L217 is closer (9 A) and contacts the Q(B)-binding pocket. From the pH dependence of the charge recombination in the RC after the first flash, we estimated deltaG(AB), the free energy difference between the Q-(A)Q(B) and Q(A)Q-(B) states, and pK212, the apparent pK of Glu-L212, a residue that is only 4 A away from Q(B). As expected, the replacement of positively charged arginines by neutral isoleucines destabilized the Q-(B) state in the L217RI mutant to a larger extent than in the L207RI one. Also as expected, pK212 increased by approximately 0.4 pH units in the L207RI mutant. The value of pK212 in the L217RI mutant decreased by 0.3 pH units, contrary to expectations. The rate of the Q-(A)Q-(B)-->Q(A)Q(B)H2 transition upon the second flash, as monitored by electrometry via the accompanying changes in the membrane potential, was two times faster in the L207RI mutant than in the wild-type, but remained essentially unchanged in the L217RI mutant. To rationalize these findings, we developed and analyzed a kinetic model of the Q-(A)Q-(B)-->Q(A)Q(B)H2 transition. The model properly described the available experimental data and provided a set of quantitative kinetic and thermodynamic parameters of the Q(B) turnover. The non-electrostatic, 'chemical' affinity of the QB site to protons proved to be as important for the attracting protons from the bulk, as the appropriate electrostatic potential. The mutation-caused changes in the chemical proton affinity could be estimated from the difference between the experimentally established pK2J2 shifts and the expected changes in the electrostatic potential at Glu-L212, calculable from the X-ray structure of the RC. Based on functional studies, structural data and kinetic modeling, we suggest a mechanistic scheme of the QB turnover. The detachment of the formed ubiquinol from its proximal position next to Glu-L212 is considered as the rate-limiting step of the reaction cycle. (+info)
DCCD inhibits the reactions of the iron-sulfur protein in Rhodobacter sphaeroides chromatophores. (4/166)N,N'-dicyclohexylcarbodiimide (DCCD) has been reported to inhibit proton translocation by cytochrome bc(1) and b(6)f complexes without significantly altering the rate of electron transport, a process referred to as decoupling. To understand the possible role of DCCD in inhibiting the protonogenic reactions of cytochrome bc(1) complex, we investigated the effect of DCCD modification on flash-induced electron transport and electrochromic bandshift of carotenoids in Rb. sphaeroides chromatophores. DCCD has two distinct effects on phase III of the electrochromic bandshift of carotenoids reflecting the electrogenic reactions of the bc(1) complex. At low concentrations, DCCD increases the magnitude of the electrogenic process because of a decrease in the permeability of the membrane, probably through inhibition of F(o)F(1). At higher concentrations (>150 microM), DCCD slows the development of phase III of the electrochromic shift from about 3 ms in control preparations to about 23 ms at 1.2 mM DCCD, without significantly changing the amplitude. DCCD treatment of chromatophores also slows down the kinetics of flash-induced reduction of both cytochromes b and c, from 1.5-2 ms in control preparations to 8-10 ms at 0.8 mM DCCD. Parallel slowing of the reduction of both cytochromes indicates that DCCD treatment modifies the reaction of QH(2) oxidation at the Q(o) site. Despite the similarity in the kinetics of both cytochromes, the onset of cytochrome c re-reduction is delayed 1-2 ms in comparison to cytochrome b reduction, indicating that DCCD inhibits the delivery of electrons from quinol to heme c(1). We conclude that DCCD treatment of chromatophores leads to modification of the rate of Q(o)H(2) oxidation by the iron-sulfur protein (ISP) as well as the donation of electrons from ISP to c(1), and we discuss the results in the context of the movement of ISP between the Q(o) site and cytochrome c(1). (+info)
Fusion of chromatophores from photosynthetic bacteria with a supported lipid layer: characterization of the electric units. (5/166)Direct electrometric measurements of membrane potential changes are a valuable tool for study of vectorial transfer of electrons, protons, and ions. Commonly model membrane systems are created by fusion of lipid/protein vesicles with lipid-coated thin films. We characterized the electric units resulting from this process using chromatophores from the purple bacterium Rhodobacter sphaeroides and either a Mylar film or a planar modified gold electrode as support. Investigation of the shunting activity of the ionophore gramicidin on the flash-induced potential change demonstrates fusion of individual chromatophores to form independent 'blisters', which preserve an interior aqueous compartment. Under current-clamp conditions the photovoltage follows the change of the membrane potential of the individual blisters. (+info)
Electrogenic proton transfer in Rhodobacter sphaeroides reaction centers: effect of coenzyme Q(10) substitution by decylubiquinone in the Q(B) binding site. (6/166)An electrometric technique was used to investigate the effect of coenzyme Q(10) (UQ), substitution by decylubiquinone (dQ) at the Q(B) binding site of reaction centers (UQ-RC and dQ-RC, respectively) on the electrogenic proton transfer kinetics upon Q(B) reduction in Rhodobacter sphaeroides chromatophores. Unlike dQ-RC, the kinetics of the second flash-induced proton uptake in UQ-RC clearly deviated from the mono-exponential one. The activation energy (about 30 kJ/mol) and the pH profile of the kinetics in dQ-RC were similar to those in UQ-RC, with the power law approximation used in the latter case. The interpretation of the data presumed the quinone translocation between the two binding positions within the Q(B) site. It is proposed that the native isoprenyl side chain (in contrast to decyl chain) favors the equilibrium binding of neutral quinone at the redox-active 'proximal' position, but causes a higher barrier for the hydroquinone movement from 'proximal' to 'distal' position. (+info)
Changes in the acyl lipid composition of photosynthetic bacteria grown under photosynthetic and non-photosynthetic conditions. (7/166)The acyl lipids and their constituent fatty acids were studied in the photosynthetic bacteria Rhodospirillum rubrum, Rhodopseudomonas capsulata and Rhodopseudomonas sphaeroides, which were grown under photosynthetic and non-photosynthetic conditions. The major lipids were found to be phosphatidylethanolamine, phosphatidylglycerol and cardiolipin in each bacterium. The two Rhodopseudomonas species also contained significant quantities of phosphatidylcholine. Other acyl lipids accounted for less than 10% of the total. On changing growth conditions from non-photosynthetic to photosynthetic a large increase in the relative proportion of phosphatidylglycerol was seen at the expense of phosphatidyl-ethanolamine. In Rhodospirillum rubrum the fatty acids of the major phospholipids showed an increase in the proportion of palmitate and stearate and a decrease in palmitoleate and vaccenate on changing growth conditions to photosynthetic. In contrast, the exceptionally high levels (>80%) of vaccenate in individual phospholipids of Rhodopseudomonas capsulata and Rhodopseudomonas sphaeroides were unaffected by changing growth conditions to photosynthetic. Analysis of the lipids of chromatophores, isolated from the three bacteria, showed that these preparations were enriched in phosphatidylglycerol. The large increase in this phospholipid, seen during growth under photosynthetic conditions, appeared, therefore, to be due to a proliferation of chromatophore membranes. Possible roles for acyl lipids in the formation and function of the photosynthetic apparatus of bacteria are discussed. (+info)
Coupling of proton flow to ATP synthesis in Rhodobacter capsulatus: F(0)F(1)-ATP synthase is absent from about half of chromatophores. (8/166)F(0)F(1)-ATP synthase (H(+)-ATP synthase, F(0)F(1)) utilizes the transmembrane protonmotive force to catalyze the formation of ATP from ADP and inorganic phosphate (P(i)). Structurally the enzyme consists of a membrane-embedded proton-translocating F(0) portion and a protruding hydrophilic F(1) part that catalyzes the synthesis of ATP. In photosynthetic purple bacteria a single turnover of the photosynthetic reaction centers (driven by a short saturating flash of light) generates protonmotive force that is sufficiently large to drive ATP synthesis. Using isolated chromatophore vesicles of Rhodobacter capsulatus, we monitored the flash induced ATP synthesis (by chemoluminescence of luciferin/luciferase) in parallel to the transmembrane charge transfer through F(0)F(1) (by following the decay of electrochromic bandshifts of intrinsic carotenoids). With the help of specific inhibitors of F(1) (efrapeptin) and of F(0) (venturicidin), we decomposed the kinetics of the total proton flow through F(0)F(1) into (i) those coupled to the ATP synthesis and (ii) the de-coupled proton escape through F(0). Taking the coupled proton flow, we calculated the H(+)/ATP ratio; it was found to be 3.3+/-0.6 at a large driving force (after one saturating flash of light) but to increase up to 5.1+/-0.9 at a smaller driving force (after a half-saturating flash). From the results obtained, we conclude that our routine chromatophore preparations contained three subsets of chromatophore vesicles. Chromatophores with coupled F(0)F(1) dominated in fresh material. Freezing/thawing or pre-illumination in the absence of ADP and P(i) led to an increase in the fraction of chromatophores with at least one de-coupled F(0)(F(1)). The disclosed fraction of chromatophores that lacked proton-conducting F(0)(F(1)) (approx. 40% of the total amount) remained constant upon these treatments. (+info)
Chromatophores are pigment-containing cells found in various organisms, including animals and plants. In animals, chromatophores are primarily found in the skin, eyes, and hair or feathers, and they play a crucial role in color changes exhibited by many species. These cells contain pigments that can be concentrated or dispersed to change the color of the cell, allowing the animal to camouflage itself, communicate with other individuals, or regulate its body temperature.
There are several types of chromatophores, including:
1. Melanophores: These cells contain the pigment melanin and are responsible for producing dark colors such as black, brown, and gray. They are found in many animals, including mammals, birds, reptiles, amphibians, and fish.
2. Xanthophores: These cells contain yellow or orange pigments called pteridines and carotenoids. They are found in many animals, including fish, amphibians, and reptiles.
3. Iridophores: These cells do not contain pigments but instead reflect light to produce iridescent colors. They are found in many animals, including fish, reptiles, and amphibians.
4. Erythrophores: These cells contain red or pink pigments called porphyrins and are found in some species of fish and crustaceans.
5. Leucophores: These cells reflect white light and are found in some species of fish, cephalopods (such as squid and octopuses), and crustaceans.
The distribution and concentration of pigments within chromatophores can be controlled by hormones, neurotransmitters, or other signaling molecules, allowing the animal to change its color rapidly in response to environmental stimuli or social cues.
Bacterial chromatophores are membranous structures within certain bacteria that contain pigments and are involved in light absorption. They are primarily found in photosynthetic bacteria, where they play a crucial role in the process of photosynthesis by capturing light energy and converting it into chemical energy.
The term "chromatophore" is derived from the Greek words "chroma," meaning color, and "phoros," meaning bearer. In bacteria, chromatophores are typically composed of one or more membrane-bound vesicles called thylakoids, which contain various pigments such as bacteriochlorophylls and carotenoids.
Bacterial chromatophores can be found in several groups of photosynthetic bacteria, including cyanobacteria, green sulfur bacteria, purple sulfur bacteria, and purple nonsulfur bacteria. The specific arrangement and composition of the pigments within the chromatophores determine the type of light that is absorbed and the wavelengths that are utilized for photosynthesis.
Overall, bacterial chromatophores are essential organelles for the survival and growth of many photosynthetic bacteria, allowing them to harness the energy from sunlight to fuel their metabolic processes.
"Rhodospirillum rubrum" is a gram-negative, facultatively anaerobic, photosynthetic bacteria species. It is commonly found in freshwater and soil environments, and it has the ability to carry out both photosynthesis and respiration, depending on the availability of light and oxygen. The bacteria contain bacteriochlorophyll and carotenoid pigments, which give them a pinkish-red color, hence the name "rubrum." They are known to be important organisms in the study of photosynthesis, nitrogen fixation, and other metabolic processes.
Rhodospirillum is a genus of purple nonsulfur bacteria that are capable of photosynthesis. These bacteria are gram-negative, motile, and spiral-shaped, with a single flagellum at each end. They are found in freshwater and soil environments, and are capable of using light as an energy source for growth. Rhodospirillum species can also fix nitrogen gas, making them important contributors to the nitrogen cycle in their habitats.
The name "Rhodospirillum" comes from the Greek words "rhodo," meaning rose-colored, and "spira," meaning coil or spiral, referring to the pinkish-red color and spiral shape of these bacteria.
It's important to note that medical definitions typically refer to conditions, diseases, or processes related to human health, so a medical definition of Rhodospirillum may not be readily available as it is not directly related to human health. However, in rare cases, some species of Rhodospirillum have been associated with human infections, such as endocarditis and bacteremia, but these are not common.
Bacteriochlorophylls are a type of pigment that are found in certain bacteria and are used in photosynthesis. They are similar to chlorophylls, which are found in plants and algae, but have some differences in their structure and absorption spectrum. Bacteriochlorophylls absorb light at longer wavelengths than chlorophylls, with absorption peaks in the near-infrared region of the electromagnetic spectrum. This allows bacteria that contain bacteriochlorophylls to carry out photosynthesis in environments with low levels of light or at great depths in the ocean where sunlight is scarce.
There are several different types of bacteriochlorophylls, including bacteriochlorophyll a, bacteriochlorophyll b, and bacteriochlorophyll c. These pigments play a role in the capture of light energy during photosynthesis and are involved in the electron transfer processes that occur during this process. Bacteriochlorophylls are also used as a taxonomic marker to help classify certain groups of bacteria.
Rhodopseudomonas is a genus of gram-negative, rod-shaped bacteria that are capable of photosynthesis. These bacteria contain bacteriochlorophyll and can use light as an energy source in the absence of oxygen, which makes them facultative anaerobes. They typically inhabit freshwater and soil environments, and some species are able to fix nitrogen gas. Rhodopseudomonas species are known to cause various infections in humans, including bacteremia, endocarditis, and respiratory tract infections, particularly in immunocompromised individuals. However, such infections are relatively rare.
Photophosphorylation is the process by which ATP (adenosine triphosphate) is produced during photosynthesis, utilizing light energy to add a phosphate group to ADP (adenosine diphosphate). This process occurs in the chloroplasts of plant cells and cyanobacteria, in a series of steps that are catalyzed by several complexes of proteins. There are two types of photophosphorylation: cyclic and non-cyclic. Cyclic photophosphorylation involves the use of only one photosystem and results in the production of ATP, while non-cyclic photophosphorylation involves the use of two photosystems and leads to the production of both ATP and NADPH, as well as the reduction of NADP+ to NADPH. Overall, photophosphorylation plays a crucial role in providing energy for various metabolic processes in plant cells and is essential for life on Earth.
Rhodobacter sphaeroides is not a medical term, but rather a scientific name for a type of bacteria. It belongs to the class of proteobacteria and is commonly found in soil, fresh water, and the ocean. This bacterium is capable of photosynthesis, and it can use light as an energy source, converting it into chemical energy. Rhodobacter sphaeroides is often studied in research settings due to its unique metabolic capabilities and potential applications in biotechnology.
In a medical context, Rhodobacter sphaeroides may be mentioned in relation to rare cases of infection, particularly in individuals with weakened immune systems. However, it is not considered a significant human pathogen, and there are no specific medical definitions associated with this bacterium.
"Sepia" is not a term used in medical definitions. It is a color, often associated with the brownish-gray ink produced by cuttlefish, and it has been used historically in photography and dyes. In the context of human health or medicine, "sepia" does not have a specific meaning or definition.
"Chromatium" is a genus of bacteria that are commonly found in aquatic environments, particularly in anaerobic or low-oxygen conditions. These bacteria are known for their ability to perform anaerobic respiration using sulfur as the final electron acceptor in the electron transport chain. This process is often referred to as "sulfur reduction" or "sulfur respiration."
The name "Chromatium" comes from the Greek word "chroma," which means "color," and refers to the distinctive purple color of these bacteria, which is due to the presence of bacteriochlorophyll and carotenoid pigments. These pigments allow Chromatium species to perform photosynthesis, using light energy to convert carbon dioxide into organic compounds.
It's worth noting that "Chromatium" is a specific taxonomic name for a genus of bacteria, and should not be confused with the more general term "chromatin," which refers to the complex of DNA, histone proteins, and other molecules that make up the chromosomes in eukaryotic cells.
Melanophores are specialized pigment-containing cells found in various organisms, including vertebrates and some invertebrates. In humans and other mammals, melanophores are primarily located within the skin's dermal layer and are part of the larger group of chromatophores.
Melanophores contain melanosomes, which are organelles that store and transport the pigment melanin. These cells play a crucial role in determining the coloration of an individual's skin, hair, and eyes by producing, storing, and distributing melanin granules within their cytoplasm.
In response to hormonal signals or neural stimulation, melanophores can undergo changes in the distribution of melanosomes, leading to variations in color intensity. This process is known as melanin dispersion or aggregation and is responsible for various physiological responses, such as skin tanning upon exposure to sunlight or the color-changing abilities observed in some animals like chameleons and cuttlefish.
It's important to note that while humans do not have the ability to change their skin color rapidly like some other animals, melanophores still play a significant role in protecting our skin from harmful ultraviolet radiation by producing melanin, which helps absorb and dissipate this energy, reducing damage to skin cells.
I could not find a medical definition for "animal fins" as a single concept. However, in the field of comparative anatomy and evolutionary biology, fins are specialized limbs that some aquatic animals use for movement, stability, or sensory purposes. Fins can be found in various forms among different animal groups, including fish, amphibians, reptiles, and even mammals like whales and dolphins.
Fins consist of either bony or cartilaginous structures that support webs of skin or connective tissue. They may contain muscles, blood vessels, nerves, and sensory organs, which help animals navigate their underwater environment efficiently. The specific structure and function of fins can vary greatly depending on the animal's taxonomic group and lifestyle adaptations.
In a medical context, studying animal fins could provide insights into the evolution of limbs in vertebrates or contribute to the development of biomimetic technologies inspired by nature. However, there is no standalone medical definition for 'animal fins.'
Pigmentation, in a medical context, refers to the coloring of the skin, hair, or eyes due to the presence of pigment-producing cells called melanocytes. These cells produce a pigment called melanin, which determines the color of our skin, hair, and eyes.
There are two main types of melanin: eumelanin and pheomelanin. Eumelanin is responsible for brown or black coloration, while pheomelanin produces a red or yellow hue. The amount and type of melanin produced by melanocytes can vary from person to person, leading to differences in skin color and hair color.
Changes in pigmentation can occur due to various factors such as genetics, exposure to sunlight, hormonal changes, inflammation, or certain medical conditions. For example, hyperpigmentation refers to an excess production of melanin that results in darkened patches on the skin, while hypopigmentation is a condition where there is a decreased production of melanin leading to lighter or white patches on the skin.
Rhodobacter capsulatus is not a medical term, but a species name in the field of microbiology. It refers to a type of purple nonsulfur bacteria that is capable of photosynthesis and can be found in freshwater and soil environments. These bacteria are known for their ability to switch between using light and organic compounds as sources of energy, depending on the availability of each. They have been studied for their potential applications in biotechnology and renewable energy production.
While not directly related to medical definitions, some research has explored the potential use of Rhodobacter capsulatus in bioremediation and wastewater treatment due to its ability to break down various organic compounds. However, it is not a pathogenic organism and does not have any direct relevance to human health or disease.
List of MeSH codes (A11)
Bacterial cell structure
Purple sulfur bacteria
List of sequenced plastomes
List of skin conditions
List of MeSH codes (A11) - Wikipedia
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Frontiers | The Puzzle of Metabolite Exchange and Identification of Putative Octotrico Peptide Repeat Expression Regulators in...
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- The cercozoan amoeba Paulinella chromatophora contains photosynthetic organelles-termed chromatophores-that evolved from a cyanobacterium ∼100 million years ago, independently from plastids in plants and algae. (frontiersin.org)
- Gene transfers from diverse bacteria compensate for reductive genome evolution in the chromatophore of Paulinella chromatophora. (avcr.cz)
- Paulinella chromatophora is a unicellular eukaryote that bears photosynthetic entities called chromatophores that are derived from cyanobacteria and has thus received much attention as a possible example of an organism in the early stages of organellogenesis. (biomedcentral.com)
- Early ultrastructural observations [ 8 ] showed that the chromatophore of Paulinella shares a suite of characteristics with extant cyanobacteria, particularly members of the genus Synechococcus , including the presence of a thick peptidoglycan wall and a similar manner of binary fission. (biomedcentral.com)
- (b) Light micrograph of a Paulinella cell bearing chromatophores. (biomedcentral.com)
- These bacterial 'organelles' are ideal model systems for studying how the organisation of the photosynthetic complexes therein shape membrane architecture. (uea.ac.uk)
- In different bacterial species, the photosynthetic core complex can take on very different organizations. (uiuc.edu)
- Figure 1 - Schematics of different organizations of the bacterial photosynthetic core complexes. (uiuc.edu)
- The question has long been: is the chromatophore just an endosymbiotic cyanobacterium or is it a photosynthetic organelle [ 9 ]? (biomedcentral.com)
- 2010. Potential of the melanophore pigment response for detection of bacterial toxicity. (oregonstate.edu)
- 2010. Conservation of the chromatophore pigment response. (oregonstate.edu)
- Fish skin contains different types of pigment cells or chromatophores, which are under the control of the hormonal and nervous systems. (drjohnson.com)
- This type of tumor is also known as the pigment cell tumor, and it is derived from the chromatophores that are found in the skin of the goldfish or other fish species, amphibians, and reptiles. (epetsquare.com)
- These are called chromatophores and contain pigments, e.g. in cyanobacteria. (excellup.com)
- What makes this organism remarkable is the presence of one or two blue-green sausage-shaped chromatophores in its cytoplasm (Figure 1b ). (biomedcentral.com)
- These findings imply that similar to the situation in mitochondria and plastids, also in P. chromatophora nuclear factors evolved that control metabolite exchange and gene expression in the chromatophore. (frontiersin.org)
- Most bacteria have not been characterised, and only about half of the bacterial phyla have species that can be grown in the laboratory. (alchetron.com)
- They are of medical importance because some fimbriae mediate the attachment of bacteria to cells via adhesins (ADHESINS, BACTERIAL). (childrensmercy.org)
- Bacterial tolerance to 6-methoxy-benzoxazolin-2-one (MBOA), the most abundant and selective antimicrobial metabolite in the maize rhizosphere, correlated significantly with the abundance of these bacteria on BX-exuding maize roots. (bvsalud.org)
- A bacterial resting cell, -- formerly considered a spore, but now known to occur even in endosporous bacteria. (rhymingnames.com)
- It imports hundreds of nucleus-encoded proteins, and diverse metabolites are continuously exchanged across the two chromatophore envelope membranes. (frontiersin.org)
- Bacterial cells can be motile or non-motile. (excellup.com)
- There are typically 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water . (alchetron.com)
- There are approximately ten times as many bacterial cells in the human microbiota as there are human cells in the body, with their largest number being in the gut flora, and a large number on the skin . (alchetron.com)
- Unlike cells of animals and other eukaryotes , bacterial cells do not contain a nucleus and rarely harbour membrane-bound organelles . (alchetron.com)
- Specialized cells called chromatophores are responsible for producing these pigmentations. (anglersadvantageguideservice.com)
- A membrane-bound organelle that is present in all plant and fungal cells and some protist, animal and bacterial cells. (hokudai.ac.jp)
- Furthermore, chromatophore-localized biosynthetic pathways as well as multiprotein complexes include proteins of dual genetic origin, suggesting that mechanisms evolved that coordinate gene expression levels between chromatophore and nucleus. (frontiersin.org)
- Here we show by mass spectrometric analyses of enriched insoluble protein fractions that, unexpectedly, nucleus-encoded transporters are not inserted into the chromatophore inner envelope membrane. (frontiersin.org)
- It mainly develops when the fish gills are damaged as a result of bacterial infection, parastials, physical injury, and toxins. (epetsquare.com)
- sphaeroides, solar energy is converted via coupled electron and proton transfer reactions within the intracytoplasmic membranes (ICMs), infoldings of the cytoplasmic membrane that form spherical 'chromatophore' vesicles. (uea.ac.uk)
- Complementary high-resolution atomic force microscopy (AFM) of intact, purified chromatophores verifies the close association of cytochrome bc1 complexes with RC-LH1-PufX dimers. (uea.ac.uk)
- The most common fatal bacterial diseases are respiratory infections, with tuberculosis alone killing about 2 million people per year, mostly in sub-Saharan Africa . (alchetron.com)
- Sudden temperature drops, for example, adding cold water or heater malfunctions, can trigger various bacterial diseases and parasites in the aquarium. (fishparlor.com)
- There are two causes for this, a form of vascular shock sometimes unexplained, sometimes caused by bacterial infection especially localizing in and spreading from the kidney can cause the fish to blanch in the middle. (drjohnson.com)
- Thus, the mechanism generating metabolic connectivity of the chromatophore fundamentally differs from the one for mitochondria and plastids, but likely rather resembles the poorly understood mechanism in various bacterial endosymbionts in plants and insects. (frontiersin.org)
- We propose that bacterial tolerance to root-derived antimicrobial compounds is an underlying mechanism determining the structure of host-specific microbial communities. (bvsalud.org)
- Apparently these chromatophore-targeted proteins evolved convergently to plastid-targeted expression regulators and are likely involved in gene expression control in the chromatophore. (frontiersin.org)
- This graph shows the total number of publications written about "Fimbriae, Bacterial" by people in this website by year, and whether "Fimbriae, Bacterial" was a major or minor topic of these publications. (childrensmercy.org)
- Bacterial fimbriae refer to common pili, to be distinguished from the preferred use of "pili", which is confined to sex pili (PILI, SEX). (childrensmercy.org)
- Below are the most recent publications written about "Fimbriae, Bacterial" by people in Profiles. (childrensmercy.org)
- Instead we identified several expanded groups of short chromatophore-targeted orphan proteins. (frontiersin.org)
- In bacterial isolates of prisoners and ex-prisoners from the general population, there were 2 strains, which had identical banding patterns, while there were clear similarities between several isolates. (who.int)
- sphaeroides, solar energy is converted via coupled electron and proton transfer reactions within the intracytoplasmic membranes (ICMs), infoldings of the cytoplasmic membrane that form spherical 'chromatophore' vesicles. (whiterose.ac.uk)
- Chameleons have several unique adaptations that allow them to change color, including specialized skin cells called chromatophores that contain pigments which can be expanded or contracted to alter the animal's hue. (wiki--travel.com)
- The color changes are controlled by specialized skin cells called chromatophores, which contain pigments that can be expanded or contracted to produce different hues. (wiki--travel.com)
- The efficiency of this process is further enhanced by the presence of specialized cells called gill cells or chromatophores, which contain pigments that help to extract oxygen from the water. (fisharticle.com)
- The chromatophores are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants. (easynotecards.com)
- Ethnic differences in COVID-19 pathogenic risks have raised more awareness on the potential immunological roles of chromatophores against autoimmune pathogens, and the studies will focus on sebum in immunological chains [6-8]. (crimsonpublishers.com)
- The book concludes by exploring the physiological aspects of bacterial luminescence as well as the taxonomy and evolution of luminous bacteria. (elsevier.com)
- Current studies on the chromatophores' influences focus on skin-brain neuroendocrine activities with solar entropic activities, and the classical studies focus on microbe bacteria [4,5]. (crimsonpublishers.com)