Aim
Pinnipeds are thought to have evolved from a North Pacific ancestor, although some fossil evidence suggests a nonmarine Arctic origin and separate invasions into the North Pacific and North ...Atlantic. We here set out to test differing hypotheses about the origin of pinnipeds through identification and age estimation of pinniped marine invasions.
Location
Arctic, North America, North Atlantic, North Pacific.
Taxon
Pinnipeds (seals, sea lions, walruses and their fossil relatives).
Methods
Because evidence indicates that taste loss in marine mammals and birds results from adaptation to the marine environment, we examined 16 representative pinnipeds for loss‐of‐function mutations in the TAS1R1, TAS1R2 and TAS1R3 genes encoding the sweet T1R2–T1R3 and umami (savory) T1R1–T1R3 receptors, and used the loss‐of‐function events of these receptors as indicators of marine invasion.
Results
Numerous loss‐of‐function mutations were found in each pinniped TAS1R (22 in TAS1R1, 21 in TAS1R2 and 42 in TAS1R3). Six mutations were shared by all phocids and six other mutations by all otarioids (otariids and odobenids), but none by all phocids and all otarioids. Selective pressures on TAS1R1, TAS1R2 and TAS1R3 were estimated to have been relaxed, respectively, 16.3, 20.1 and 19.8 million years ago (Myra) in phocids, and 12.1, 18.1 and 18.2 Myra in otarioids.
Main conclusions
All TAS1Rs, T1R1–T1R3 and T1R2–T1R3 are nonfunctional in all extant pinnipeds. Both receptors lost their function approximately 20 Myra in the Phocidae lineage and approximately 18 Myra in the Otarioidea lineage. Both lineages have colonized the marine realm independently, which entails nonmarine origins of both Pinnipedia and its stem lineage. Combined with fossil evidence, molecular findings here suggest an Arctic centre of long‐lasting (approximately 38–18 Myra) nonmarine pinniped evolution and at least five separate marine invasions, with the extinct (enaliarctid, Desmatophocidae, Kolponomos) and Otarioidea lineages entering the North Pacific and the Phocidae lineage the North Atlantic.
A bioluminescent immunoassay system was developed to determine serine/threonine protein kinase activity using an aequorin-labeled monoclonal antibody and a synthetic peptide as the substrate. A ...monoclonal antibody against the synthetic phosphorylated serine peptide (K9P peptide) of histone H3 (19 amino acid residues), referred to as the H3S10P antibody, was chemically conjugated to maleimide-activated aequorin to prepare aequorin-labeled H3S10P (AQ-S-H3S10P). For the serine/threonine kinase assay, a non-phosphorylated serine peptide (K9C peptide) coated on a microplate was incubated with serine/threonine protein kinase in the presence of ATP and Mg2+. The resulting phosphorylated K9C peptides (K9P peptide) were identified using AQ-S-H3S10P. Thus, after the removal of unbound AQ-S-H3S10P though washing, the serine/threonine kinase activity was determined by the luminescence activity of aequorin from AQ-S-H3S10P bound to the K9P peptide. This assay system, in combination with the K9C peptide and AQ-S-H3S10P, could be used to screen inhibitors of various serine/threonine protein kinases in general.
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•The K9C peptide of histone H3 is used as a substrate for Ser/Thr protein kinase.•A monoclonal antibody against phosphorylated K9C peptide was labeled with aequorin.•Phosphorylated K9C peptide is detected using an aequorin-labeled antibody.•Ser/Thr kinase activity was determined with luminescence activity of aequorin.•Inhibition on Ser/Thr kinase by chemicals is determined by aequorin activity.
Objective
ε‐Poly‐l‐lysine (PLL) is a cationic polymer consisting of 25–35 l‐lysine residues. Our previous study revealed that fluorescently labelled PLL can stain the stratum corneum (SC) via ionic ...interactions between PLL and SC constituents. In this study, to further clarify the mechanisms underlying the interaction between PLL and the SC, the staining properties of fluorescent PLL were compared with that of fluorescently labelled anionic dextran (aDex), which has approximately the same molecular weight as PLL.
Methods
SC samples were collected by non‐invasive tape stripping and stained with fluorescent PLL and/or fluorescent aDex. Fluorescence images were acquired using a fluorescence microscope and then analysed.
Results
The SC could be stained with either fluorescent PLL or aDex, both of which were inhibited by the addition of high concentrations of salt solutions. In particular, aDex staining was inhibited at a lower salt concentration than PLL staining. Moreover, PLL staining was inhibited under acidic conditions, while aDex staining was inhibited under neutral to alkaline conditions. Double staining of SC with both fluorescent polymers produced heterogeneous staining patterns: corneocytes stained with both polymers, corneocytes stained with PLL or aDex in a mutually exclusive manner, and unstained corneocytes. Staining of SC samples from the face was more extensive than staining of SC samples from the inside of the upper arm with both polymers. In addition, pretreatment of the SC with ethanol resulted in enhanced staining with both polymers. These results suggest that double staining of SC with both polymers can provide information on the damaged SC.
Conclusion
Staining of SC with fluorescent PLL depends on its properties of a cationic and hydrophobic polymer with appropriate molecular size, which can distinguish the damaged SC. Double staining of SC with fluorescent PLL and aDex is a novel approach to obtain information for the analysis of skin conditions.
Résumé
Objectif
La ε‐poly‐L‐lysine (PLL) est un polymère cationique constitué de résidus de 25 à 35 L‐lysines. Notre précédente étude a révélé que la PLL marquée par fluorescence peut colorer le stratum corneum (SC) par des interactions ioniques entre la PLL et les constituants du SC. Dans cette étude, afin de clarifier davantage les mécanismes sous‐jacents à l’interaction entre la PLL et le SC, les propriétés de coloration de la PLL fluorescent ont été comparées à celles du dextran anionique (aDex) marqué par fluorescence, qui a à peu près le même poids moléculaire que la PLL.
Méthodes
Les échantillons SC ont été prélevés par «tape stripping» non invasif et colorés avec de la PLL fluorescente et/ou de l’aDex fluorescent. Les images de fluorescence ont été acquises au microscope à fluorescence puis analysées.
Résultats
Le SC pouvait être coloré avec de la PLL ou de l’aDex fluorescents, tous deux inhibés par l’ajout de fortes concentrations de solutions salines. En particulier, la coloration par aDex était inhibée à une concentration en sel inférieure à la coloration par PLL. En outre, la coloration de la PLL a été inhibée dans des conditions acides, tandis que la coloration de l’aDex a été inhibée dans des conditions neutres à alcalines. La double coloration de SC avec les deux polymères fluorescents a produit des modes de coloration hétérogènes: cornéocytes colorés avec les deux polymères, cornéocytes colorés avec de la PLL ou de l’aDex d’une manière mutuellement exclusive, et cornéocytes non colorés. La coloration des échantillons de SC sur le visage était plus étendue que la coloration des échantillons de SC sur la face intérieure du haut du bras avec les deux polymères. En outre, le prétraitement du SC avec de l’éthanol a entraîné une coloration améliorée avec les deux polymères. Ces résultats indiquent qu’une double coloration du CS avec les deux polymères peut fournir des informations sur le CS endommagé.
Conclusion
La coloration du CS avec de la PLL fluorescente dépend de ses propriétés de polymère cationique et hydrophobe de taille moléculaire appropriée, ce qui permet de distinguer le CS endommagé. La double coloration de SC avec de la PLL et de l’aDex fluorescents est une nouvelle approche pour obtenir des informations pour l’analyse des affections cutanées.
Double staining of the stratum corneum with fluorescent ε‐poly‐l‐lysine and anionic dextran resulted in a heterogeneous pattern of corneocytes reflecting skin conditions.
Abstract
Controversy and misunderstanding surround the role of feeding specialization in taste receptor loss in vertebrates. We refined and tested the hypothesis that this loss is caused by feeding ...specializations. Specifically, feeding specializations were proposed to trigger time-dependent process of taste receptor loss through deprivation of benefit of using the receptor’s gustatory function. We propose that this process may be accelerated by abiotic environmental conditions or decelerated/stopped because of extragustatory functions of the receptor’s protein(s). As test case we used evolution of the sweet (TAS1R2+TAS1R3) and umami (TAS1R1+TAS1R3) receptors in Carnivora (dogs, cats, and kin). We predicted these receptors’ absence/presence using data on presence/absence of inactivating mutations in these receptors’ genes and data from behavioral sweet/umami preference tests. We identified 20 evolutionary events of sweet (11) or umami (9) receptor loss. These events affected species with feeding specializations predicted to favor sweet/umami receptor loss (27 and 22 species, respectively). All species with feeding habits predicted to favor sweet/umami receptor retention (11 and 24, respectively) were found to retain that receptor. Six species retained the sweet (5) or umami (1) receptor despite feeding specialization predicted to favor loss of that receptor, which can be explained by the time dependence of sweet/umami receptor loss process and the possible decelerating effect of TAS1R extragustatory functions so that the sweet/umami receptor process is ongoing in these species. Our findings support the idea that feeding specialization leads to taste receptor loss and is the main if not only triggering factor for evolutionary loss of taste receptors.
We present a series of quantum states that are characterized by dark solitons of the nonlinear Schrödinger equation (i.e. the Gross-Pitaevskii equation) for the one-dimensional Bose gas interacting ...through the repulsive delta-function potentials. The classical solutions satisfy the periodic boundary conditions and we simply call them classical dark solitons. Through exact solutions we show corresponding aspects between the states and the solitons in the weak coupling case: the quantum and classical density profiles completely overlap with each other not only at an initial time but also at later times over a long period of time, and they move together with the same speed in time; the matrix element of the bosonic field operator between the quantum states has exactly the same profiles of the square amplitude and the phase as the classical complex scalar field of a classical dark soliton not only at the initial time but also at later times, and the corresponding profiles move together for a long period of time. We suggest that the corresponding properties hold rigorously in the weak coupling limit. Furthermore, we argue that the lifetime of the dark soliton-like density profile in the quantum state becomes infinitely long as the coupling constant approaches zero, by comparing it with the quantum speed limit time. Thus, we call the quantum states quantum dark soliton states.
Clytin II (CLII) is a Ca2+-binding photoprotein and has been identified as an isotype of clytin I (CLI). CLII consists of apoCLII (an apoprotein) and 2-peroxide of coelenterazine (an adduct of ...molecular oxygen to coelenterazine), which is identical to the widely used Ca2+-binding photoprotein, aequorin (AQ). However, CLII triggered by Ca2+ exhibits a 4.5-fold higher maximum luminescence intensity (Imax) compared to both AQ and CLI, and it is approximately 5 times less sensitive to Ca2+ than AQ. To confirm the suitability of the preferred human codon-optimized CLII (pCLII) gene for cell-based G-protein-coupled receptor (GPCR) assays, a transformant stably expressing apoprotein of pCLII using the pCLII gene in the mitochondria of CHO–K1 cells was established and in situ regenerated pCLII in the cells were applied to the high-throughput screening system. An ATP-stimulated GPCR assay for endogenous P2Y purinergic receptors was confirmed using the established stable transformant.
•The Ca2+-binding photoprotein clytin II with a high signal-to-noise ratio is applied to the assays.•Preferred human codon-optimized clytin II (pCLII) gene is expressed efficiently in CHO–K1 cells.•The pCLII gene with the signal peptide sequence is expressed in the mitochondria of CHO–K1 cells.•CHO–K1 cells stably expressing the pCLII gene in mitochondria are established for the GPCR assay.•ATP-stimulated GPCR assay of endogenous P2Y purinergic receptors are successfully performed.
Cesium lead halide (CsPbX3, X = Cl, Br, or I) perovskite quantum dots (QDs) are known as ionic nanocrystals, and their optical properties are greatly affected by the washing solvent used during the ...purification process. Here, we demonstrate the purification process of CsPbBr3 perovskite QDs using low-dielectric-constant solvents to completely remove impurities, such as the reaction solvent and desorbed ligands. The use of the ether solvent diethylene glycol dimethyl ether (diglyme), having a low dielectric constant of ε = 7.23, as a poor solvent for reprecipitation allowed for multiple wash cycles, which led to high purity and high photoluminescence quantum yield for CsPbBr3 QDs. The light-emitting device constructed with the CsPbBr3 QDs and washed twice with diglyme (two-wash) showed a low turn-on voltage of 2.7 V and a peak external quantum efficiency of over 8%. Thus, the purification of perovskite QDs with multiple wash cycles using a low-dielectric-constant solvent is an effective approach for enhancing not only the optical properties but also the efficiency of perovskite quantum dot light-emitting devices.
The structure-activity relationship (SAR) for a novel series of catechol conjugated siderophore cephalosporins is described with their in vitro activities against multi-drug resistant Gram-negative ...pathogens including Pseudomonas aeruginosa, Acinetobacter baumannii, Stenotrophomonas maltophilia and Enterobacteriaceae. Cefiderocol (3) was one of the best molecules which displayed well-balanced and potent activities against multi-drug resistant Gram-negative pathogens including carbapenem resistant bacteria among the prepared compounds with the modified C-7 side chain and the modified C-3 side chain. Cefiderocol (3) is a highly promising parenteral cephalosporin for the treatment of multi-drug resistant Gram-negative infection.
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•New catechol conjugated cephalosporins were synthesized.•Most of them exhibited potent antibacterial activities against MDR Gram-negative pathogens.•The relationship between the chelating activity with Fe3+ and the antibacterial activities was discussed.•Cefiderocol (3) is a highly promising parenteral cephalosporin for the treatment of multi-drug resistant Gram-negative infection.
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