Voluntary running exercise alters microbiota composition and increases n-butyrate concentration in the rat cecum

The effects of voluntary wheel-running exercise on cecal microbiota and short-chain fatty acid production were investigated in rats. The microbiota composition was notably different between the exercised and sedentary rats. Furthermore, the exercised rats showed a significantly higher n-butyrate concentration than the sedentary rats. This alteration of the cecal microbial environment may contribute to the beneficial effect of exercise on gastrointestinal disorders.     

Immuno-gold Localization of Nitrate Reductase in Spinach (Spinacia oleracea) Leaves

The intracellular location of nitrate reductase in spinach leaveswas examined by applying an immunocytochemical method. Thinsections were first treated with immunopurified anti-nitratereductase monospecific antibodies, followed by incubation withcolloidal gold-labelled goat anti-rabbit immunoglobulin G asa marker. The nitrate reductase was specifically located inthe chloroplast. When anti-nitrate reductase antibodies wereomitted, or when pre-immune serum was used no label was observed. (Received October 30, 1986; Accepted December 25, 1986)     

Efficient Solar‐Driven Water Oxidation over Perovskite‐Type BaNbO2N Photoanodes Absorbing Visible Light up to 740 nm

Photoelectrochemical water splitting using semiconductors absorbing a wide range of visible light is a potentially attractive means of harvesting large portions of the solar spectrum. However, this is also very challenging because narrowing the semiconductor band gap lowers the driving force for photoreactions. Herein, a highly active perovskite BaNbO₂N exhibiting photoexcitation up to 740 nm for water oxidation is reported. The synthesis route, consisting of moderate nitridation and subsequent annealing in inert Ar flow, enhances the crystallinity of the BaNbO₂N surface without inducing the reduction of the Nb species. As a result, a particulate BaNbO₂N photoanode exhibits a photocurrent of 5.2 mA cm^?2 at 1.23 V_RHE under simulated solar irradiation, which is the highest yet reported for an oxynitride responsive at wavelengths above 600 nm. Suppressing the reduction of B‐site cations during the synthesis of perovskite AB(O,N)₃, which otherwise results in surface defects or impurities, is critical for achieving high water oxidation activity.     

First record of the brown lanternshark,Etmopterus unicolor, from the waters around New Zealand, and comparison with the southern lanternshark,E. granulosus

Specimens of the brown lanternshark,Etmopterus unicolor, reported here for the first time from the waters around New Zealand, were caught on bottom longlines. This study compares morphometeric and meristic characters of New Zealand and Japanese specimens ofE. unicolor and New Zealand specimens of the southern lanternshark,E. granulosus. E. unicolor andE. granulosus are clearly distinguishable by the height of the first dorsal fin, number of spiral valves, number of vertebrae, and shape of the dermal denticles and teeth.     

Development of intestinal microbiota in mice and its possible interaction with the evolution of luminal IgA in the intestine.

The development of the intestinal microbiota and the evolution of the fecal IgA in mice were analyzed from 18 to 40 days old by PCR temperature gradient gel electrophoresis (TGGE) and ELISA, respectively. There were two events for the diversification of the intestinal microbiota from suckling to maturity. The first change occurred between days 21 and 22 after birth, when the diversity of the intestinal microbiota showed a remarkable increase at this time. The second change occurred from days 27 to 30 after birth, and the increase in the diversity of the intestinal microbiota ceased. The amount of fecal IgA decreased from days 18 to 20, remained low until day 22, on day 23, it recovered and then continued to increase. This study suggests that there are possible interactions between the development of intestinal microbiota and the evolution of intestinal secretion of IgA in mice, the same as in rats, although the second change in mice intestinal microbiota occurred a few days later than in rats. The decline in maternal IgA supply as the suckling period proceeded presumably allowed the bacterial colonization. As a consequence of this increase in bacterial colonization, the secretion of the self-SIgA was accelerated in the pups.     

Transient Acceleration of Epidermal Growth Factor Receptor Dynamics Produces Higher-Order Signaling Clusters

Cell signaling depends on spatiotemporally regulated molecular interactions. Although the movements of signaling proteins have been analyzed with various technologies, how spatial dynamics influence the molecular interactions that transduce signals is unclear. Here, we developed a single-molecule method to analyze the spatiotemporal coupling between motility, clustering, and signaling. The analysis was performed with the epidermal growth factor receptor (EGFR), which triggers signaling through its dimerization and phosphorylation after association with EGF. Our results show that the few EGFRs isolated in membrane subdomains were released by an EGF-dependent increase in their diffusion area, facilitating molecular associations and producing immobile clusters. Using a two-color single-molecule analysis, we found that the EGF-induced state transition alters the properties of the immobile clusters, allowing them to interact for extended periods with the cytoplasmic protein, GRB2. Our study reveals a novel correlation between this molecular interaction and its mesoscale dynamics, providing the initial signaling node.     

Development of vaccines against pertussis caused by Bordetella holmesii using a mouse intranasal challenge model

Bordetella holmesii is recognized as the third causative agent of pertussis (whooping cough) in addition to Bordetella pertussis and Bordetella parapertussis. Pertussis caused by B. holmesii is not rare around the world. However, to date, there is no effective vaccine against B. holmesii. We examined the protective potency of pertussis vaccines available in Japan and vaccines prepared from B. holmesii. A murine model of respiratory infection was exploited to evaluate protective potency. No Japanese commercial pertussis vaccines were effective against B. holmesii. In contrast, a wBH vaccine and an aBH vaccine prepared from B. holmesii were both protective. Passive immunization with sera from mice immunized with aBH vaccine established protection against B. holmesii, indicating that B. holmesii‐specific serum antibodies might play an important role in protection. Immuno‐proteomic analysis with sera from mice immunized with aBH vaccine revealed that the sera recognized a BipA‐like protein of B. holmesii. An aBH vaccine prepared from a BipA‐like protein‐deficient mutant strain did not have a protective effect against B. holmesii. Taken together, our results suggest that the BipA‐like protein plays an important role in the protective efficacy of aBH vaccine.     

An exception among diatoms: unique organization of genes involved in isoprenoid biosynthesis in Rhizosolenia setigera CCMP 1694

The marine diatom Rhizosolenia setigera is unique among this group of microalgae given that it is only one of a handful of diatom species that can produce highly branched isoprenoid (HBI) hydrocarbons. In our efforts to determine distinguishing molecular characteristics in R. setigera CCMP 1694 that could help elucidate the underlying mechanisms for its ability to biosynthesize HBIs, we discovered the occurrence of independent genes encoding for two isopentenyl diphosphate isomerases (RsIDI1 and RsIDI2) and one squalene synthase (RsSQS), enzymes that catalyze non‐consecutive steps in isoprenoid biosynthesis. These genes are peculiarly fused in all other genome‐sequenced diatoms to date, making their organization in R. setigera CCMP 1694 a clear distinguishing molecular feature. Phylogenetic and sequence analysis of RsIDI1, RsIDI2, and RsSQS revealed that such an arrangement of individually transcribed genes involved in isoprenoid biosynthesis could have arisen through a secondary gene fission event. We further demonstrate that inhibition of squalene synthase (SQS) shifts the flux of exogenous isoprenoid precursors towards HBI biosynthesis suggesting the competition for isoprenoid substrates in the form of farnesyl diphosphate between the sterol and HBI biosynthetic pathways in this diatom.