Chromosome constitution of hybrid strains constructed by protoplast fusion between the tomato and strawberry pathotypes of <Emphasis Type="Italic">Alternaria alternata</Emphasis>

To analyze the genetics of host-specific toxin production and its relation to the specific pathogenicity of a mitosporic fungus Alternaria alternata, we developed a protoplast fusion system. Protoplasts of drug-resistant transformants of the A. alternata tomato pathotype (AAL-toxin producer) and A. alternata strawberry pathotype (AF-toxin producer) were fused by electrofusion. Of five fusion strains examined, two strains were pathogenic on both tomato and strawberry host plants, whereas the rest of the fusion strains were pathogenic only on tomato. Pulsed-field gel electrophoresis analysis demonstrated that the hybrid strains pathogenic on both tomato and strawberry carry 1.0- and 1.05-Mb conditionally dispensable (CD) chromosomes derived, respectively, from the parental strains of the tomato and strawberry pathotypes. On the other hand, the fusion strains appeared to maintain only a single homologous chromosome derived from one of the parental strain in the case of essential chromosomes (A chromosomes). The results suggest that fusion strains between two different pathotypes of A. alternata might be haploid resulting from the deletion of extra sets of essential chromosomes in the fused nuclei, whereas the CD chromosomes derived from each parental strain could be maintained stably in a new genetic background with an expanded range of pathogenicity. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank database under the accession numbers AB469331to AB469354.     

Growth and maturation in sterlet <Emphasis Type="Italic">Acipenser ruthenus</Emphasis> under high concentrations of dissolved oxygen

This study investigates the effect of high dissolved oxygen concentrations (DO) on sterlet Acipenser ruthenus maturation. Two groups, each comprising 246 individuals of 8-month-old juvenile sterlets, were reared for 37 months under high DO (group H, mean DO of 11.2 mg/L) or normal DO (group C, mean DO of 7.3 mg/L). Significant differences in body weight were observed between group H (638.7?±?191.9 g) and group C (572.2?±?151.9 g) in 12 months (P?<?0.05). Growth until 12 months occurred at a specific growth rate of 0.6%/day for group H and at 0.5%/day for group C. The food conversion rate of groups H and C was 5.2 and 5.8, respectively. The gonadosomatic index of group H was 3.1?±?1.1 for females and 3.1?±?9.7 for males, and showed no significant difference with group C (3.0?±?0.7 for females and 2.8?±?8.9 for males, P?>?0.05) in 24 months. Significant differences in follicle diameter in mature females were also observed. Group H included 68 mature females, with an average follicle diameter of 2318.0?±?175.3 µm, whereas group C included 56 mature females, with a smaller average follicle diameter of 2152.3?±?287.0 µm (P?<?0.001). However, the polarization index in group H (0.194?±?0.049) was higher than that in group C (0.178?±?0.042) (P?<?0.05). These results suggest that, for sterlet, rearing conditions with high DO can affect growth of both the body and follicle diameter of fish compared to normal rearing conditions.     

Keratoconus in a cynomolgus monkey

In a seven-year-old male cynomolgus monkey, erythema of the upper eyelid and forehead and corneal opacity, edema and conical protrusion in the eye were observed. At necropsy, ophthalmological and serological examinations revealed binocular corneal opacity and conical protrusion and a high IgE level, respectively. Thinning of the epithelium and stroma of the cornea were noted histopathologically. At the center of the corneal epithelium, the number of epithelial cells was reduced, their cytoplasm was poorer and the basal cells were flatter than at the periphery. Bowman's membrane was folded with partial loss or breakage. Collagen fibers were compacted or disarranged, and the keratocytes were increased in the stroma, with focal pyknosis or loss of the endothelium and folding of Descemet's membrane. Electron microscopical examination revealed atrophy of the corneal epithelial basal cells. This is the first report of a case of keratoconus in a cynomolgus monkey.     

Avarol Induces Apoptosis in Pancreatic Ductal Adenocarcinoma Cells by Activating PERK–eIF2α–CHOP Signaling

Avarol is a sesquiterpenoid hydroquinone with potent cytotoxicity. Although resolving endoplasmic reticulum (ER) stress is essential for intracellular homeostasis, erratic or excessive ER stress can lead to apoptosis. Here, we reported that avarol selectively induces cell death in pancreatic ductal adenocarcinomas (PDAC), which are difficult to treat owing to the availability of few chemotherapeutic agents. Analyses of the molecular mechanisms of avarol-induced apoptosis indicated upregulation of ER stress marker BiP and ER stress-dependent apoptosis inducer CHOP in PDAC cells but not in normal cells, suggesting that avarol selectively induces ER stress responses. We also showed that avarol activated the PERK–eIF2α pathway but did not affect the IRE1 and ATF6 pathways. Moreover, CHOP downregulation was significantly suppressed by avarol-induced apoptosis. Thus, the PERK–eIF2α–CHOP signaling pathway may be a novel molecular mechanism of avarol-induced apoptosis. The present data indicate that avarol has potential as a chemotherapeutic agent for PDAC and induces apoptosis by activating the PERK–eIF2α pathway.     

Epidermal Tissue-Derived T-cell Growth Factor,Colony Stimulating Factor and Nerve Growth Factor in Chickens

The purpose of this study was to determine the mechanism of the local cytokine-mediated immune response in the skin of chickens. The incorporation of 3H-thymidine into spleen T lymphocytes from 9- to 10-week-old chickens was augmented by the addition of epidermal tissue culture supernatant (ESN) from 11-day-old embryos. The colony formation of neonatal chicken bone marrow cells in the methylcellulose medium was also significantly increased by addition of ESN. When axonal outgrowth in matrigel was investigated, the embryonal sympathetic ganglion was found to grow axons outwards towards the epidermal tissue specimens. The above results suggest that chicken epidermal cells (probably keratinocytes) produce T-cell growth factor (corresponding to IL-1), colony-stimulating factor for macrophages (M-CSF) and granulocytes (G-CSF), and nerve growth factor (NGF).     

An electron microscopic examination of fulvic acid

An electron microscopic examination of fulvic acid shows that the crystallinity, shapes, dimensions and extent of aggregation vary with pH. At pH 2.5, three types of particles can be observed: small spheroids (15–20 Å in diameter), aggregates of spheroids (200–300 Å in diameter) and an amorphous material of low contrast, perforated by voids, 500–1,100 Å in diameter. spheroidal aggregates tend to form elongated, irregularly shaped structures, 20,000–30,000 Å long.At pH 3.5, which is the natural pH of a dilute fulvic acid solution, electron micrographs show a sponge-like structure of variable thickness (100–300 Å), punctured by voids, 200–1,000 Å in diameter.At pH 4.5 and higher, electron micrographs show flat sheet-like lamellae of very low contrast, perforated by voids, 200–2,000 Å in diameter.Electron diffraction patterns show crystallinity in fulvic acid aggregates formed at pH 2.5 only but not in those formed at pH 3.5. The electron microscopic data are in harmony with X-ray, chemical and spectroscopic data on the same fulvic acid, and point to a relatively “openlrd structure, perforated by voids of varying dimensions which can trap or fix organic and inorganic compounds that fit into the voids, provided that the charges are complementary.     

Changes in reproductive patterns in relation to decline in stock abundance of the Japanese mantis shrimp Oratosquilla oratoria in Tokyo Bay

ABSTRACT:   We investigated changes in the reproductive patterns of mantis shrimp Oratosquilla oratoria concurrent with stock-abundance decline in Tokyo Bay, Japan. Stock abundance was high in the mid to late 1980s but decreased abruptly in the early 1990s. The yearly change in annual mean larval abundance was similar to that of stock abundance. Mantis shrimp in the bay have two spawning seasons, an early season (May–June) for ≥1-year-old individuals and a late season (July–September) for 0–1-year-old individuals. This general reproductive pattern does not differ among different stock-abundance levels. However, the monthly pattern in larval abundance has changed with stock-abundance decline; larval abundance from the early spawning season was highest in the high-stock-abundance period, and it decreased significantly in the low-stock-abundance period, probably as a result of decreased spawning-stock abundance of large female mantis shrimp ≥1-year-old. Correlation analysis on the egg production index and larval abundance suggested that during this low-stock-abundance period the population is supported mostly by late-hatched larvae spawned by small, 0–1-year-old female mantis shrimp. Considering the reproductive pattern and the present status of the fishery, the stock of small female mantis shrimp should be conserved to enhance reproduction of the population for stock recovery.     

Contribution of the grain size QTL GS3 to yield properties and physiological nitrogen-use efficiency in the large-grain rice cultivar ‘Akita 63’

The development of crop varieties with high nitrogen-use efficiency (NUE) is thought to be important in achieving sustainable cereal crop production. The high yield large-grain rice cultivar Oryza sativa L. ‘Akita 63’ (temperate japonica) has high physiological NUE (PNUE) for grain yield (GY). Our previous study revealed that a large-grain allele of GS3 is present in ‘Akita 63’. Here, we verified the influence of GS3 on the yield properties and PNUE for GY in ‘Akita 63’. The frequency distribution of brown rice length in F₂ crosses of ‘Iwate 75’ and ‘Akita 63’ showed a continuous distribution that could be explained by GS3. A near-isogenic line was developed to substitute the GS3 segment of ‘Koshihikari’, which harbours a normal-sized grain allele, in the genetic background of ‘Akita 63’ and the line was designated as Akita63NILGS3-Koshihikari. Compared with Akita63NILGS3-Koshihikari, ‘Akita 63’ exhibited a significantly increased grain length, single brown grain weight and GY, although no significant differences were observed in the nitrogen content and above-ground biomass per unit of cultivated area. These results indicate that the GS3 large-grain allele is a contributing factor to high PNUE for GY in ‘Akita 63’. These findings will facilitate the development of nitrogen-efficient rice varieties.