"Helium spots": caused by a diapiric magma from the upper mantle

"Helium spots," where a significant amount of helium is present in the soil [up to 350 parts per million with a high (3)He to (4)He ratio of (8.90 +/- 0.31) x 10(-6)], have been found along the fault zone formed by the 1966 Matsushiro swarm earthquakes. The formation of the "helium spots" and the occurrence of the earthquakes are interpreted as the results of a diapiric uprise of a magma approximately 1 kilometer in diameter.     

Isolation of the non-fastidious microalga with astaxanthin-accumulating property and its potential for application to aquaculture

Astaxanthin has recently attracted considerable attention for its biological properties such as the antioxidant activity as well as a coloring agent used for farmed fish. However, its biological production, mainly by a green microalgae Haematococcus pluvialis, is costly because of its fastidious growth characters. Therefore, for future applications of biological astaxanthin production in aquaculture, non-fastidious microalgal strains were isolated from environmental samples, examined for their astaxanthin-accumulating activity, and characterized phylogenetically. While β-carotene was found in all tested isolates, one isolate, GK12, from activated sludge of a sewage treatment plant accumulated 2.5 ± 0.36 mg/g dry cell of free astaxanthin de novo under photoautotrophic culture condition, which was comparable to photoautotrophic cultures of other known astaxanthin-accumulating microorganisms. Mixotrophic culture conditions increased GK12 biomass, but astaxanthin content was decreased, suggesting that the simple photoautotrophic cultivation is more efficient way for GK12 to produce astaxanthin than mixotrophic cultivation. A phylogenetic study of SSU rDNA strongly suggested that GK12 is a novel species in the genus Monoraphidium, Chlorophyta. Besides making efforts to increase astaxanthin-productivity of known astaxanthin accumulators, it is also beneficial to study GK12 from the view point of applications to aquaculture.     

Aged Garlic Extract Scavenges Superoxide Radicals

There is increasing evidence to suggest that many degenerative or pathological processes, such as aging, cancer, and coronary heart disease, are related to reactive oxygen species and radical-mediated reactions. We examined the effectiveness of aged garlic extract (AGE), a garlic preparation rich in water-soluble cysteinyl moieties, and its component for scavenging of superoxide by using the hypoxanthine-xanthine oxidase and human neutrophils. In the hypoxanthine-xanthine oxidase system, electron spin resonance showed that aged garlic extract scavenged superoxide radicals in a dose-dependent manner up to 54%. The EC₅₀ value of aged garlic extract for the superoxide radical scavenging effect was 0.80 mg/ml. N-α-(1-deoxy-D-fructos-1-yl)-L-arginine (25.9%) and (1S, 3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-1,3-dicarboxylic acid (20.8%), water-soluble moieties of AGE, also exerted superoxide scavenging effects. Phorbol 12-myristate 13-acetate-activated human neutrophils produced superoxide radical of 56.6 ± 9.27 nmol/min/10⁷ cells. Aged garlic extract (3 mg/ml) significantly inhibited superoxide production in comparison to the control. These data suggest that aged garlic extract may be useful for preventing diseases associated with reactive oxygen species.     

Relation between seeding times and stem yield of sorghum in cold region in Japan

The seeding time is an important factor affecting the process of stem yield. Nevertheless, details related to the optimum seeding time to maximize the stem yield of sweet sorghum have not been studied. This study elucidated information necessary to ascertain the optimum seeding time to obtain the maximum stem yield. We conducted an examination with three seeding times at intervals of two weeks, ranging from late May to mid-June for four years during 2009–2012, and we analyzed the relation between seeding times and stem yield based on internode characteristics of stems using two sorghum cultivars with different maturity: ‘Kazetachi’ and ‘Wray’. Differences were observed in the respective relations between the seeding times and the stem yields. For Kazetachi, the dry matter yield increased with the earlier seeding time. Thus, to expand the growing period, an earlier seeding time with good establishment is better. For Wray, a cultivar that can grow to heading in the Tohoku region, the stem dry weight was greater by seeding in early June. For cultivars such as Wray with a sufficient growing period in a given region, the optimum seeding time to obtain stable higher stem yield existed and the cultivars should be seeded when they could grow under good weather conditions at the critical time strongly influences growth.     

Nondestructive evaluation of egg-to-adult development and feeding behavior of the bamboo powderpost beetle <Emphasis Type="Italic">Dinoderus minutus</Emphasis> using X-ray computed tomography

The life history and feeding biology of the bamboo powderpost beetle Dinoderus minutus remain poorly understood because the beetles’ oviposition, development, and feeding take place inside bamboo culms. In this study, X-ray computed tomography (CT) was employed to nondestructively quantify the progression of larval body size and tunnel size from the first instar to pupation. Eggs of D. minutus laid between laminates of nutrient-containing filter paper were easily collected. The newly hatched larvae were inoculated singly into pieces of internodes of madake (Phyllostachys bambusoides). The pieces were scanned using a microfocus X-ray CT system every 3–5 days to visualize the beetles’ bodies and tunnels with resolutions of 18–60 μm/voxel. CT scans were continued after adult eclosion to analyze pre-mating adult feeding. The collected eggs were 0.84 ± 0.06 mm (mean ± SD) in length and the egg duration lasted 5.0 ± 0.8 days. Based on CT images, the larvae grew to 3.53 ± 0.23 mm in body length and turned into pupae of 3.42 ± 0.09 mm. The larvae bored tunnels with a length of 80.2 ± 4.8 mm and a volume of 68.0 ± 7.0 mm³ over the larval period of 61 ± 11 days. Newly emerged adults remained in the bamboo pieces to feed before making exit holes in 8 ± 1 days after adult eclosion. During this period, they bored tunnels at rates of 2.64 ± 0.58 mm/day in length and 4.87 ± 1.10 mm³/day in volume.     

<Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>-mediated transformation for random insertional mutagenesis in <Emphasis Type="Italic">Colletotrichum lagenarium</Emphasis>

Random insertional mutagenesis using a marker DNA fragment is an effective method for identifying fungal genes relevant to morphogenesis, metabolism, and so on. Agrobacterium tumefaciens-mediated transformation (AtMT) has long been used as a tool for the genetic modification of a wide range of plant species. Recent study has indicated that A. tumefaciens could transfer T-DNA not only to plant cells but also to fungal cells. In this study, AtMT was applied to Colletotrichum lagenarium for random insertional mutagenesis. We constructed a binary vector pBIG2RHPH2 carrying a hygromycin-resistant gene cassette between the right and left borders of T-DNA. Optimal co-cultivation of C. lagenarium wild-type 104-T with pBIG2RHPH2-introduced A. tumefaciens C58C1 led to the production of 150–300 hygromycin-resistant transformants per 10⁶ conidia. Southern blot analysis revealed that T-DNA was mainly integrated at a single site in the genome and at different sites in transformants. The T-DNA inserts showed small truncations of either end, but the hygromycin-resistant gene cassette inside the T-DNA was generally intact. The mode of T-DNA insertion described above resulted in highly efficient gene recovery from the transformants by thermal asymmetrical interlaced-polymerase chain reaction. The fungal genomic DNA segments flanking T-DNA were identified from five of eight mutants that had defective melanin biosynthesis. The sequence from one of the segments was identical to that of the melanin biosynthesis gene PKS1 of C. lagenarium, which we previously characterized. These results strongly support our notion that AtMT is a possible tool for tagging genes relevant to pathogenicity in the plant pathogenic fungus C. lagenarium.