Three-dimensional readout of flash x-ray images of living sperm in water by atomic-force microscopy

The imaging of living specimens in water by x-ray microscopy can be greatly enhanced with the use of an intense flash x-ray source and sophisticated technologies for reading x-ray images. A subnanosecond [corrected] x-ray pulse from a laser-produced plasma was used to record the x-ray image of living sea urchin sperm in an x-ray resist. The resist relief was visualized at high resolution by atomic-force microscopy. Internal structure of the sperm head was evident, and the carbon density in a flagellum was estimated from the relief height.     

Susceptibility difference between methicillin‐susceptible and methicillin‐resistant Staphylococcus aureus to a bovine myeloid antimicrobial peptide (BMAP‐28)

A bovine myeloid antimicrobial peptide antimicrobial peptide (BMAP‐28) is a member of the cathelicidin family and acts as a component of innate immunity. There are few reports of susceptibility difference of methicillin‐resistant Staphylococcus aureus (MRSA) and susceptible strains (MSSA) against BMAP‐28. This study aims to clarify how a few amino acid substitutions of BMAP‐28 are related to its antimicrobial activity using four analog peptides of BMAP‐28. We also compared cellular fatty acid components of MSSA and MRSA using gas chromatography. We found that a few amino acid substitutions of BMAP‐28 do not change antimicrobial activity. It was also revealed that the percentage of cis‐11‐eicosenoic acid in total detected fatty acids of MRSA was significantly higher than that of MSSA. In addition, the percentage of palmitic acid in total detected fatty acids of MRSA tended to be lower than that of MSSA. Our results will provide new information to deal with the question of differences in bacterial susceptibility against BMAP‐28.     

Effect of food amount and temperature on growth rate and aerobic scope of juvenile chum salmon

Offshore migration of Pacific salmon Oncorhynchus spp. is partly triggered by increasing body size and high motility in the early stages of life. The survival of juvenile salmon may depend on their growth rate during the first few months in the sea, and this factor partly regulates the dynamics of adult populations. Here, we assessed the effects of water temperature and food availability on the growth of juvenile chum salmon O. keta. In addition, by combining the measurements of metabolic performance for growth and activity (Absolute Aerobic Scope: AAS) with a bioenergetics model, we estimated the energy allocation for different activities in the juveniles. Under high temperatures (14 °C), juveniles reared at low food levels (1% body weight) allocated less than half their energy for growth than those reared at high food levels (4% body weight). These findings suggest that high temperature and low food level constrain the growth of juveniles, providing an insight into the effect of the recent increase in warm and low-nutrient water masses on survival of juveniles and catches of adult chum salmon on the Pacific side of Honshu Island, Japan.

     

A low body-color regulating ability of spotted halibut Verasper variegatus: Evaluation of the roles of melanin-concentrating hormone and proopiomelanocortin systems

In teleosts, melanin-concentrating hormone (MCH) induces body brightening. On the other hand, α-melanophore-stimulating hormone (α-MSH), derived from the precursor proopiomelanocortin (POMC), leads to body darkening. In many teleosts, the expression level of pmch is high in light backgrounds, while that of pomc is low in dark backgrounds. In the present study, we investigated the ability of spotted halibut Verasper variegatus to regulate body coloration. Intraperitoneal administration of MCH resulted in a dose-dependent brightening of body color. The body color and brain contents of pmch1 and pmch2 in spotted halibut acclimated to the black or white background were not almost affected by background color. In addition, pituitary mRNA levels of pomc-a, pomc-b, and pomc-c genes in fish acclimated to the white background often exceed those levels of fish kept under the black background. These results suggest that the weak response of expression levels of pmch genes in response to background color is a factor in the blunt ability of spotted halibut to regulate body color. The different profiles of pomc gene expression to background color compared to that reported in other teleosts may be another factor for the weak ability of body color change in the spotted halibut.

     

Development of a multiplex allele‐specific primer PCR assay for simultaneous detection of QoI and CAA fungicide resistance alleles in Plasmopara viticola populations

BACKGROUND: DNA‐based diagnosis has become a common tool for the evaluation of fungicide resistance in obligate phytopathogenic fungus Plasmopara viticola. RESULTS: A multiplex allele‐specific primer PCR assay has been developed for the rapid detection of fungicide resistance in P. viticola populations. With this assay, a glycine‐to‐alanine substitution at codon 143 of the P. viticola cytochrome b gene, which conferred QoI fungicide resistance, and a glycine‐to‐serine substitution at codon 1105 of the P. viticola cellulose synthase gene PvCesA3, which conferred CAA fungicide resistance, were detected simultaneously. CONCLUSION: It is suggested that the present assay is a reliable tool for the rapid and simultaneous detection of QoI and CAA fungicide resistance alleles in P. viticola populations. The assay required only 2 h from the sampling of symptoms to the detection of resistance alleles to both fungicides. Copyright © 2012 Society of Chemical Industry     

Ingestion of proteoglycan fraction from shark cartilage increases serum inhibitory activity against matrix metalloproteinase-9 and suppresses development of N-nitrosobis(2-oxopropyl)amine-induced pancreatic duct carcinogenesis in hamster

A water extract of shark cartilage was fractionated into acidic and basic fractions by preparative isoelectric focusing on the basis of the amphoteric nature of samples. The acidic fraction was further fractionated into ethanol-soluble and -precipitate fractions. After the carcinogenesis treatment using N-nitrosobis(2-oxopropyl)amine, hamsters received a diet containing each fraction or purified chondroichin sulfate to give 0.4% (w/w) for 50 days. Only administration of the acidic ethanol-precipitate-fraction-containing diet significantly increased serum inhibitory activity against matrix metalloproteinase (MMP)-9 and reduced the number of adenocarcinomas in the pancreatic duct. The active fraction predominantly consisted of chondroichin sulfate-containing proteoglycan. However, the purified chondroichin sulfate had no significant activity. These results suggest that the protein moiety of the proteoglycan might be involved in the increase of serum inhibitory activity against MMP-9 and suppression of pancreatic carcinogenesis in hamster.     

A natural two-nucleotide deletion affirms role for NADPH oxidase in pathogenicity and perithecium formation in Fusarium graminearum species complex

Members of the Fusarium graminearum species complex are known to cause head blight of wheat. A natural nonpathogenic mutant, strain Fa0233007, was found in the strain collection of the Japanese F. graminearum species complex. In addition, this strain cannot form perithecia. Complete linkage of these deficiencies in the progenies obtained from crossing a wild-type strain and the mutant strain suggested that a single genomic locus was responsible for deficiencies in both traits. The locus was mapped to chromosome 1 using sequence-tagged markers. An NADPH oxidase gene (NoxA, FGSG00739) was identified in the mapped region, and a 2-bp deletion that results in premature termination of the open reading frame was detected in the gene. Both pathogenicity and perithecium formation were recovered by FGSG00739 complementation in the mutant strain.     

Chromospheric anemone jets as evidence of ubiquitous reconnection

The heating of the solar chromosphere and corona is a long-standing puzzle in solar physics. Hinode observations show the ubiquitous presence of chromospheric anemone jets outside sunspots in active regions. They are typically 3 to 7 arc seconds = 2000 to 5000 kilometers long and 0.2 to 0.4 arc second = 150 to 300 kilometers wide, and their velocity is 10 to 20 kilometers per second. These small jets have an inverted Y-shape, similar to the shape of x-ray anemone jets in the corona. These features imply that magnetic reconnection similar to that in the corona is occurring at a much smaller spatial scale throughout the chromosphere and suggest that the heating of the solar chromosphere and corona may be related to small-scale ubiquitous reconnection.     

Complete amino acid sequence of the Mu heavy chain of a human IgM immunoglobulin

The amino acid sequence of the micro, chain of a human IgM immunoglobulin, including the location of all disulfide bridges and oligosaccharides, has been determined. The homology of the constant regions of immunoglobulin micro, gamma, alpha, and epsilon heavy chains reveals evolutionary relationships and suggests that two genes code for each heavy chain.