Development of collagen fibres and lysyl oxidase expression in the presumptive dermis of chick limb bud

Lysyl oxidase (LOX) plays a critical role in the formation of cross-linkages in extracellular matrix molecules. Thus, it is essential for the biogenesis and homeostasis of the connective tissue matrix. During development, collagen fibres and elastic system fibres emerge and accumulate in a temporospatial manner in the presumptive dermis of chicks. In this study, we investigated LOX mRNA expression by laser capture microdissection and RT-qPCR and LOX protein localization by immunohistochemistry. The picrosirius polarization method was used to investigate a relation between collagen accumulation and LOX expression. PCR analysis showed that the expression of LOX mRNA in the presumptive dermis became apparent at embryonic day 13 and increased considerably by ED17. Immunohistochemical staining for LOX in the dermis was very low at all stages of development. Accumulation of collagen fibres was seen in the dermis on ED10, and higher wavelengths of birefringence became evident by ED13. Our findings suggest that the temporal pattern of LOX mRNA expression correlates with collagen fibre accumulation in the dermis of the developing chick limb bud, whereas LOX expression was relatively constant at the protein level.     

Statistical Analysis of Metal Concentrations in a Sediment Core to Reveal Influences of Human Activities on Atmospheric Environment for 200 Years

Metal concentrations in a sediment core from a moat outside Osaka Castle in Japan were measured by ICP-MS following a microwave extraction method. Concentrations of metals in the sediment core samples peaked around 1945 when the World War II ended. This is in part due to great air raids on Osaka. In cluster analysis using metal concentrations, the fractions of sediment core samples were classified into two groups, representing natural sources (1795–1915) and anthropogenic sources (1922–1976), respectively. Results of lead isotope ratios also showed the anthropogenic influences from 1915 by changing the ratio values compared to those of natural sources. In addition, several components contributing to metal concentrations were identified by principal component analysis. The main component was controlled by natural sources and a decrease of the component score corresponded to an increased influence from anthropogenic sources. The largest impact of anthropogenic sources was shown around 1945.     

Immobilization of Boron and Arsenic in Alkaline Coal Fly Ash through an Aging Process with Water and Elucidation of the Immobilization Mechanism

We previously reported that a simple treatment—addition of only small amounts of water to coal fly ash (CFA) to form CFA paste followed by aging for 1–4 weeks—is advantageous for the immobilization of highly soluble B, F, Cr, and As. In this study, we investigated the leachability of Ca, SO₄, B, and As over time from non-aged and aged CFA samples to elucidate a possible immobilization mechanism. For this purpose, two types of CFA samples, one showing effective immobilization of B and As by water addition and aging (sample A) and the other showing less or no immobilization (sample B), were examined. Calcium and SO₄, B, and As in non-aged sample A dissolved immediately after the start of the leaching test, indicating that these elements existed in highly soluble particles. After the rapid dissolution, their concentrations in the leachate gradually increased, possibly due to the dissolution of glassy phases. During the 1-week leaching test, the B and As concentrations in the leachate finally decreased. The addition of only small amounts of water to CFA (Sample A) for aging produce both alkaline and supersaturation conditions for the formation of several types of Ca-bearing secondary minerals such as calcite and ettringite, which are formed under alkaline conditions. Boron and As originally existing as highly soluble particles in CFA are expected to be incorporated into and/or sorbed on these secondary minerals as water-insoluble phases. Compared to non-aged CFA, their leachability from the aged sample A remained lower throughout the entire leaching test. Possibly due to these secondary minerals being formed on the CFA surface, B and As dissolutions associated with glassy phases are also prevented. In contrast, the pH of the leachate from CFA (sample B) at the beginning of the leaching test was acidic and then abruptly became alkaline. This means that water-soluble particles that can produce acidic conditions are also contained in these alkaline CFAs. Dissolution of these substances during aging makes it difficult to generate alkaline conditions in the CFA paste. Consequently, the formation of secondary minerals and the concomitant immobilization of toxic elements are prevented.     

Chilling-injury in cucumbers. V. Polysaccharide changes in cell walls

A decline in the hot-water-soluble pectin and an increase in the hot-water-insoluble pectin were observed when cucumber fruits were subjected to chilling temperatures. Infrared absorption spectra revealed the presence of highly esterified carboxyl groups in the soluble pectin, and of free carboxyl groups in the insoluble pectin. An increase of the insoluble pectin during chilling was also found in other chilling-sensitive plants. From these results it is suggested that a de-esterification of pectin and the concomitant increase of polymeric pectin takes place during chilling, making cell walls firmer, and that these pectic changes may be a characteristic common to a number of chilling-sensitive plants.     

cDNA cloning and expressions of cytochrome P450 1A in zebrafish embryos

Cytochrome P450 1A (CYP1A) is well known for being induced by aromatic hydrocarbons, including 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD). We determined the complete cDNA sequence of a CYP1A open reading frame with both 5'- and 3'-ends in zebrafish (zfCYP1A), a useful model for environmental toxicology. zfCYP1A shows high percentage identity with CYP1As of mammals, domestic fowl and xenopus (51.9-60.4%), as well as the other fish species (63.8-89.2%). As revealed by in situ hybridization and immunohistochemistry, zfCYP1A was scarcely detected in control embryos but was markedly induced by TCDD especially in heart, vascular endothelial cells, intestinal epithelium, pronephros and outer integument in both prehatched and hatched embryos. These expression patterns are consistent with possible involvement of zfCYP1A in TCDD-induced toxicities.     

Calcium uptake and resistance to bacterial wilt of mutually grafted tomato seedlings

Bacterial wilt of tomato (Lycopersicon esculentum Mill.) caused by Ralstonia solanacearum Smith is a serious disease in Japan. We previously reported that calcium (Ca) nutrition in tomato significantly affected the resistance to the disease, and that highly resistant cultivars were characterized by a high Ca uptake. We examined the relationship between the Ca uptake and resistance using mutually grafted seedlings of tomato cultivars differing in their resistance. A susceptible (‘Ponderosa’) or moderately resistant (‘Zuiei’) cultivar (scion) was grafted on the rootstock of a susceptible, moderately resistant, or highly resistant cultivar (‘Hawaii 7998’). Roots or petioles of the grafted seedlings were inoculated with the pathogen, and the development of bacterial wilt was observed. Although Ca uptake by shoot increased by grafting on the rootstock of a highly resistant cultivar, the development of the disease was not influenced by the difference in Ca uptake, and depended on the resistance of the cultivar to which the inoculated part of the graft belonged. It was concluded that the differences in Ca uptake of the shoot of the grafted tomato seedlings might not be related to the expression of the resistance to bacterial wilt.     

The impact of nigorobuna crucian carp larvae/fry stocking and rice-straw application on the community structure of aquatic organisms in Japanese rice fields

We examined the effects of predation by Nigorobuna Carassius auratus grandoculis larvae and fry, a crucian carp endemic to Lake Biwa, Japan, on the community structure of aquatic organisms in rice fields. Six experimental plots with three different rice-straw treatments in the presence/absence of stocked larvae were prepared. In each plot, the number of aquatic organisms ranging in size from 30 μm to 5 mm in the water, as well as those from 63 μm to 5 mm in size in the surface sediments, was surveyed 6, 13, 20, 26, 34, and 41 days after the onset of irrigation. Three-day-old fish larvae were released on day 10. Undigested organisms in the gut contents of the larvae or fry were identified on days 20, 26, 34, and 41, respectively. Ten-day-old larvae mainly preyed on Cladocera, but the fry thereafter shifted to Diptera as their main prey. While Cladocera and Podocopida decreased in fish-stocked plots, Euglenales and Halteriida became more abundant there. Top-down or bottom-up effects of fish seemed to control these changes in community structure.     

Assessing and enhancing the antimicrobial effect of nisin in soy-seasoned salmon Oncorynchus keta roe using a Pediococcus pentosaceus fermentate and pectin

The compatibility and potential of nisin, a Pediococcus pentosaceus fermentate, and pectin to inhibit Listeria monocytogenes in soy-seasoned salmon roe at 5 and 12°C was studied. The compatibility of nisin and soy-seasoning was assessed by adding 6.3 μg/g of nisin to freshly washed or soy-seasoned (60% soy, 15% sweet-sake, 5% sugar, and 15% water) roe and monitoring the growth of an inoculum of L. monocytogenes (5.6 Log CFU/g; strains IID 578, IID 581, ATCC 7644) as well as residual nisin concentrations at 12°C. The combined antimicrobial potential was determined by monitoring growth of the inoculum (5.2 Log CFU/g) in roe when the soy-seasoning contained nisin (0.05 g/ml), fermentate powder made by freeze-drying a broth culture of P. pentosaceus (0.1 g/ml), and 2% pectin at 5 or 12°C. Chloride content, total acid content, and the effect of pectin on acceptability of roe were also determined. Nisin was more effective in soy-seasoned roe than in freshly washed roe. Microbial growth was completely inhibited by a combination of soy-seasoning, nisin, the fermentate, and pectin. Despite its viscosity, pectin did not significantly affect the chemical properties or acceptability of roe relative to pectin-free roe samples (P < 0.05). Based on these results, we conclude that nisin’s potential as an antimicrobial agent in soy-seasoned roe can be enhanced using fermentates and pectin.     

An annual faecal 16S amplicon sequencing of individual sea cucumber (Apostichopus japonicus) demonstrates the feeding behaviours against eukaryotes in natural environments

To fill in the gaps in knowledge as to how individual sea cucumber Apostichopus japonicus behave consuming eukaryotic food sources in natural environments, eukaryotic communities in the faeces of sea cucumbers and sediments were analysed through one whole year based on 16S rRNA gene sequencing of the organelle genomes. A total of 390 eukaryotic features were obtained, and 99.7% of the features were assigned to chloroplasts. The eukaryotic communities in faeces and sediments showed seasonal fluctuations through one whole year based on Bray‐Curtis distance and community composition. Comparison of eukaryotic communities between faeces and sediments showed that 12 families including Chaetocerotaceae and Laminariaceae were more abundant in faeces than in sediments, suggesting that sea cucumbers may choose sediment containing these algal taxa more often compared with others in natural environments. All features of Laminariaceae were assigned to Saccharina japonica, which is consistent with the fact that this alga is one of the most suitable diets in the aquaculture of A. japonicus. Assessments of individual 16S amplicon sequences of both faecal and sediment samples could be an alternative tool to help us understand dynamic feeding behaviours of sea cucumber populations in contributing to bioresource conservation and development of a superior approach to aquaculture.     

Pathogenicity of fowl adenovirus isolated from gizzard erosions to immuno-suppressed chickens

Pathogenicity of a fowl adenovirus (FAV), JM1/1 strain of serotype 1 derived from gizzard erosions of a broiler chicken, was examined to specific pathogen-free (SPF) chickens pre-treated with infectious bursal disease viruses (IBDVs) or cyclophosphamide (CY). Virulent IBDVs, classical type, were inoculated orally at 3 days of age of SPF chickens. CY was treated subcutaneously for 3 days after hatch. FAV was given orally at 30 days of age. At 40 days of age, all chickens were bled and autopsied for serology and gross observation. Gizzard lesions were ranked by the scores depending on their severities. IBDV- or CY-treated chickens showed significantly higher gizzard lesion scores than non treated birds. There were no gross lesions in any other organs except for bursal atrophy. Serologically, antibody production against FAV was highly suppressed by IBDV infection or CY treatment.