Anisotropy and corotation of galactic cosmic rays

The intensity of Galactic cosmic rays is nearly isotropic because of the influence of magnetic fields in the Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using the large data sample of the Tibet Air Shower Arrays. Besides revealing finer details of the known anisotropies, a new component of Galactic cosmic ray anisotropy in sidereal time is uncovered around the Cygnus region direction. For cosmic-ray energies up to a few hundred TeV, all components of anisotropies fade away, showing a corotation of Galactic cosmic rays with the local Galactic magnetic environment. These results have broad implications for a comprehensive understanding of cosmic rays, supernovae, magnetic fields, and heliospheric and Galactic dynamic environments.     

Analyses of leaves from open field-grown transgenic poplars overexpressing xyloglucanase

The transgenic expression of Aspergillus xyloglucanase cDNA (AaXEG2) with 35S promoter in the leaves of open field-grown poplars was studied. The level of xyloglucan in the transgenic poplars was decreased to 15–16% in the non-fertile soil (forest-field soil) and to 21–22% in the fertile soil (farming-field soil) compared with that of the wild-type poplars. The leaves exhibited a smaller surface area with more rounded teeth than those of the wild-type plants, similar to the sun leaf variety that was grown in the incubation room and subsequently greenhoused. The majority of total veins with water-conducting vascular bundles were shorter in the leaves of the transgenic poplars than those of the wild type. This decrease in vein length may result from a decrease in xyloglucan during leaf development, from which large numbers of proteins were markedly downregulated in the leaves of the transgenic plants via proteomic analysis. It seems likely that the leaves of the transgenic poplars came to relax the edges of their tooth rather than extend their veins as a result of the loosening of the xyloglucan cellulose networks in the leaves.     

Mapping of a gene that confers short lateral branching (slb) in melon (Cucumis melo L.)

Plant architecture plays an important role in the yield, product quality, and cultivation practices of many crops. Branching pattern is one of the most important components in the plant architecture of melon (Cucumis melo L.). ‘Melon Chukanbohon Nou 4 Go’ (Nou-4) has a short-lateral-branching trait derived from a weedy melon, LB-1. This trait is reported to be controlled by a single recessive or incompletely dominant major gene called short lateral branching (slb). To find molecular markers for marker-assisted selection of this gene, we first constructed a linkage map using 94 F₂ plants derived from a cross between Nou-4 and ‘Earl’s Favourite (Harukei-3)’, a cultivar with normal branching. We then conducted quantitative trait locus (QTL) analysis and identified two loci for short lateral branching. A major QTL in linkage group (LG) XI, at which the Nou-4 allele is associated with short lateral branching, explained 50.9 % of the phenotypic variance, with a LOD score of 12.5. We suggest that this QTL corresponds to slb because of the magnitude of its effect. Another minor QTL in LG III, at which the Harukei-3 allele is associated with short lateral branching, explained 9.9 % of the phenotypic variance, with a LOD score of 4.2. Using an independent population, we demonstrated that an SSR marker linked to the QTL in LG XI (slb) could be used to select for short lateral branching. This is the first report of mapping a gene regulating the plant architecture of melon.     

Pigment pattern formation by contact-dependent depolarization

Although recent experimental studies have suggested that the interactions among the pigment cells play a key role in the skin pattern formation, details of the mechanism remain largely unknown. By using an in vitro cell culture system, we have detected interactions between the two pigment cell types, melanophores and xanthophores, in the zebrafish skin. During primary culture, the melanophore membrane transiently depolarizes when contacted with the dendrites of a xanthophore. This depolarization triggers melanophore migration to avoid further contact with the xanthophores. Cell depolarization and repulsive movement were not observed in pigment cells with the jaguar mutant, which shows defective segregation of melanophores and xanthophores. The depolarization-repulsion of wild-type pigment cells may explain the pigment cell behaviors generating the stripe pattern of zebrafish.     

Dysfunction of erythropoietin-producing interstitial cells in the kidneys of ICR-derived glomerulonephritis (ICGN) mice

Anemia is a major secondary symptom in chronic renal disorder (CRD), but the precise cause of insufficient production of erythropoietin (EPO) remains unclear owing to the controversial localization of EPO-producing cells in the kidneys. The ICR-derived glomerulonephritis (ICGN) mouse, a new hereditary nephrotic mouse, is an appropriate model of anemia associated with CRD. By using an amplified in situ hybridization technique, we detected and counted the renal EPO-producing cells under both normoxic and hypoxic conditions. The expression levels of renal EPO mRNA were quantified and oxygen gradients were also assessed immunohistochemically. Amplified in situ hybridization clarified that EPO-producing cells were peritubular interstitial cells in the middle region of renal cortex in both ICR and ICGN mice. Hypoxia (7% O2) induced low oxygen tension in proximal tubular epithelial cells of renal cortex, and increased the expression of EPO mRNA and the number of EPO-producing cells in both ICR and ICGN mice. However, hypoxia did not increase the serum EPO levels in ICGN mice. The ICGN mouse is a good model for anemia associated with CRD, and the suppression of EPO protein production in the renal EPO-producing cells is considered to be a potential cause of anemia associated with CRD.     

Detection of DNA of 'Candidatus Mycoplasma haemominutum' and Spiroplasma sp. in unfed ticks collected from vegetation in Japan

DNA fragments of 'Candidatus Mycoplasma haemominutum', a feline heamobartonella pathogen, were detected from unfed Ixodes ovatus collected from vegetation in Hokkaido, Fukushima and Yamaguchi Prefectures, and unfed Haemaphysalis flava in Yamaguchi Prefecture. This finding suggests that ixodid tick is a possible vector of 'C. Mycoplasma haemominutum'. Spiroplasma DNA was also detected from unfed I. ovatus in Hokkaido, Fukushima and Yamaguchi Prefectures. The analysis of nucleotides sequence suggested that this Spiroplasma was distinct from registered species.     

Identification of endophytic <Emphasis Type="Italic">Streptomyces</Emphasis> sp. R-5 and analysis of its antimicrobial metabolites

In a previous study, endophytic Streptomyces sp. R-5 isolated from a field-grown rhododendron was able to confer disease resistance on tissue-cultured seedlings of rhododendron when applied to medium surfaces in flasks. Here, the isolate was identified as Streptomyces galbus Frommer based on various physiological characteristics and analysis of the 16S rDNA sequence. Its major antimicro-bial metabolites were identified as actinomycin X₂ and fungichromin by analyses using liquid chromatography/mass spectometry and nuclear magnetic resonance.     

Characterization of a new viroid strain from hops: evidence for viroid speciation by isolation in different host species

A new viroid was detected in hops cultivated in Akita Prefecture, Japan where it is prevalent in many hops fields. In a survey of hop samples collected during the 1986–2002 growing seasons, the new viroid was present in the major Japanese hop-cultivating areas as early as the 1980s. A single-stranded circular RNA of 368–372 nucleotides that assume a highly basepaired, stable, rod-like secondary structure, shares 93%–98% sequence homology with Apple fruit crinkle viroid (AFCVd) isolated from apple and 85%–87% with Australian grapevine viroid (AGVd) isolated from grapevine. Taking into account the present concept of viroid species, we conclude that the viroid is AFCVd. Circumstantial evidence suggests that AFCVd from apples and hops were endemic in Japan only where cultivation of the two host plants overlapped, thereby strongly supporting the possibility that AFCVd (or an ancestral viroid) was transmitted across the species barrier from apples to hops or hops to apples somewhere in the region. Phylogenetic analysis of AFCVd from hops, AFCVd from apples, and AGVd together with the other members of the genus Apscaviroid revealed that the Akita isolates of AFCVd from hops (AFCVd-hop) formed a cluster that is distinct from AFCVd-apple and AGVd. Accumulation of host-specific sequence variation following their isolation in different host species may be leading to the formation of two viroid species from a common ancestor.     

Occurrence of ateliosis in Japanese Black calves and their secretory function of growth hormone

Unthrifty calves occurred sporadically in Japanese Black (beef cattle) in an area in northeastern Japan. The states of unthrifty development, pedigree, clinico-biochemistry and the secretory function of bovine growth hormone (bGH) in pituitary were investigated. The total cholesterol concentration and CK, AST and LDH activities in the serum showed higher values than those of control calves. Basal bGH concentrations in the serum and bGH secretory reactivity in the insulin tolerance test (ITT) were showed to be significantly lower than those of the control calves. Furthermore, sperm donated from a specific bull had been used for these unthrifty calves. This study suggested that the present occurrence of unthrifty calves represented ateliosis possibly caused by congenital hypopituitarism which decreased of bGH secretory function.     

Renal microangiography and correlated histopathological observation of cows with nephropathy.

Seven Holstein-Friesian cows showing chronic nephropathy were studied by renal microangiography and its correlated histopathology. In cases of pyelonephritis associated with severe pathological lesions such as thickening of arterial walls, narrowing of the arterial and arteriolar lumen, and interstitial inflammation and abscess formation, patchy loss of the peritubular capillary plexus from the cortex to the medulla was clearly demonstrated by microangiography. Interlobular arteries were tortuous and attenuated or truncated. Opacification in the vasa rectae and interstitial capillaries was increased. Extensive non-perfused regions could be detected in the cortex. In cases of mild interstitial nephritis and moderate pyelonephritis, microangiography showed focal changes in the renal vasculature. Microangiography is thus shown to clearly demonstrate changes in the renal vasculature corresponding to the severity of the histopathological lesions.