The flagellin gene of Borrelia miyamotoi sp. nov. and its phylogenetic relationship among Borrelia species

Abstract We have cloned and sequenced the flagellin gene from Borrelia miyamotoi strain HT31 and compared it with previously published flagellin sequences. Sequence similarity analysis demonstrated that strain HT31 is phylogenetically distant from the three species of Lyme disease borreliae and is deeply branched into the relapsing fever borrelia cluster. The result was in full agreement with the classification of Borrelia strains using 16S rRNA sequences. This finding indicates that a phylogenetic analysis using flagellin gene sequences might be useful for classification of Borrelia strains.     

Bis deficiency results in early lethality with metabolic deterioration and involution of spleen and thymus

Bcl-2 interacting cell death suppressor (Bis), also known as Bag3 or CAIR-1, is involved in antistress and antiapoptotic pathways. In addition to Bcl-2, Bis binds to several proteins, suggesting it has diverse functions in normal and pathological conditions. To better define the physiological function of Bis in vivo, we developed bis-deficient mice with a cre-loxP system. Targeted disruption of exon 4 of the bis gene was demonstrated by Southern blotting and PCR, and Western blotting showed that no intact or truncated Bis protein was synthesized in bis(-/-) mice. While heterozygotes were fertile and appeared normal, Bis-deficient mice showed growth retardation and died by 3 wk after birth. The relative weight of the thymus and spleen was reduced and the total numbers of white blood cells, splenocytes, and thymocytes were significantly reduced compared with wild-type littermates. Serum profiles indicated significant hypoglycemia as well as decrease in triglyceride and cholesterol levels. Expression profiles of metabolic genes indicated that gluconeogenesis and beta-oxidation are activated in the liver of bis(-/-) mice. This activation, as well as a decrease in peripheral fat and an induction of fatty liver, appears to be an adaptive response to hypoglycemia. Our study reveals that the absence of Bis has considerable influences on postnatal growth and survival, possibly due to a nutritional impairment.     

Linear and nonlinear relationships between neuronal activity, oxygen metabolism, and hemodynamic responses

We investigated the relationship between neuronal activity, oxygen metabolism, and hemodynamic responses in rat somatosensory cortex with simultaneous optical intrinsic signal imaging and spectroscopy, laser Doppler flowmetry, and local field potential recordings. Changes in cerebral oxygen consumption increased linearly with synaptic activity but with a threshold effect consistent with the existence of a tissue oxygen buffer. Modeling analysis demonstrated that the coupling between neuronal activity and hemodynamic response magnitude may appear linear over a narrow range but incorporates nonlinear effects that are better described by a threshold or power law relationship. These results indicate that caution is required in the interpretation of perfusion-based indicators of brain activity, such as functional magnetic resonance imaging (fMRI), and may help to refine quantitative models of neurovascular coupling.     

Food preferences and nematode parasitism in mycophagousDrosophila

Food preferences and nematode parasitism were studied in natural populations of mycophagousDrosophila in and near Sapporo, northern Japan. Species which preferred fresh mushrooms showed species-specific responses toPleurotus mushrooms:D. pirka bred only onPleurotus cornucopiae, D. trivitata onP. cornucopiae andP. ostreatus, D. trilineata on these twoPleurotus mushrooms and some other mushrooms, whileD. sexvittata bred on a wide variety of mushrooms but seldom onPleurotus mushrooms. Species which preferred decayed mushrooms (D. quadrivittata, D. histrioides, D. testacea and species of thequinaria species-group) showed host preferences different from those of the above species. The rate of parasitism by nematodes was generally higher in species which prefer decayed mushrooms than in species which prefer fresh mushrooms. Among species which prefer fresh mushrooms, onlyD. trilineata was parasitized frequently by nematodes. It was not clear what factors determine the rate of parasitism in these mycophagousDrosophila. D. pirka, D. trivittata andD. trilineata passed through three or four generations per year and entered reproductive diapause in early September in and near Sapporo. Bionomics of Drosophilidae (Diptera) in Hokkaido, IX.     

Evolutionary trends of the hairy-faceSaguinus in terms of the dental and cranial morphology

Shape variations in the dentition and the cranium were analyzed for sevenSaguinus forms of the hairy-face tamarin by applying the factor analysis method. The results obtained for the dental and cranial measurements were almost consistent with each other. The magnitude of the difference in shape factors between theS. nigricollis group and theS. midas group is appreciably larger than that between the former group and theS. mystax group. If the ancestral geographic centre of origin is postulated as being within the region which is inhabited by the livingS. nigricollis group, the morphological distances between any pairs of groups correlate well with the geographic distances between them. Concerning the dental and cranial morphologies, the physical changes in the three species group probably took place in two directions; that is, from theS. nigricollis group to theS. mystax group, and from theS. nigricollis group to theS. midas group. The forms belonging to each species group are more closely related to each other, with the exception ofS. imperator in theS. mystax group. The uniqueness ofS. imperator was clearly demonstrated by factor analysis and distance analysis. In theS. mystax group, although still hypothetical,S. imperator may have been related only through the basic ancestral stock toS. labiatus andS. mystax.     

A cladistic analysis of interspecific relationships ofSaguinus

The dental and cranial morphologies of all species ofSaguinus, S. oedipus, S. geoffroyi, S. leucopus, S. nigricollis, S. fuscicollis, S. labiatus, S. mystax, S. imperator, S. bicolor, andS. midas are examined. The following hypotheses are developed by cladistic methodology, using only synapomorphic characters to assess the interspecific relationships ofSaguinus.Saguinus are divided into two main groups; one consists ofS. oedipus, S. geoffroyi, andS. leucopus, and the other includesS. inustus, S. nigricollis, S. fuscicollis, S. labiatus, S. mystax, S. imperator, S. bicolor, andS. midas. In the former group,S. oedipus is more closely related toS. geoffroyi than either is toS. leucopus. In the latter group,S. labiatus, S. mystax, andS. imperator are classified into one group, andS. bicolor andS. midas form one monophyletic group.     

Antioxidant compounds have potent anti-fibrillogenic and fibril-destabilizing effects for alpha-synuclein fibrils in vitro

The aggregation of alpha-synuclein (alphaS) in the brain has been implicated as a critical step in the development of Lewy body diseases (LBD) and multiple system atrophy (MSA). Various antioxidants not only inhibit the formation of beta-amyloid fibrils (fAbeta), but also destabilize preformed fAb in vitro. Using fluorescence spectroscopy with thioflavin S and electron microscopy, here we examined the effects of the antioxidants nordihydroguaiaretic acid, curcumin, rosmarinic acid, ferulic acid, wine-related polyphenols [tannic acid, myricetin, kaempferol (+)-catechin and (-)-epicatechin], docosahexaenoic acid, eicosapentaenoic acid, rifampicin and tetracycline on the formation of alphaS fibrils (falphaS) and on preformed falphaS. All molecules, except for docosahexaenoic acid and eicosapentaenoic acid, dose-dependently inhibited the formation of falphaS. Moreover, these molecules dose-dependently destabilized preformed falphaS. The overall activity of the molecules examined was in the order of: tannic acid=nordihydroguaiaretic acid=curcumin=rosmarinic acid=myricetin>kaempferol=ferulic acid>(+)-catechin=(-)-epicatechin>rifampicin=tetracycline. These compounds with anti-fibrillogenic as well as antioxidant activities could be key molecules for the development of preventives and therapeutics for LBD and MSA as well as Alzheimer's disease.