Basic characterization of avian β‐defensin genes in the Japanese quail,Coturnix japonica

In this study, we identified a cluster of 14 avian β‐defensins (AvBD; approximately 66 kbp) in the Japanese quail, Coturnix japonica. Except for AvBD12 (CjAvBD12) and ‐13, the CjAvBDs coding sequences exhibited greater than 78.0% similarity to the respective orthologous chicken AvBD genes (GgAvBD). The putative amino acid sequence encoded by each CjAvBD contained six cysteine residues and the GXC (X1‐2) motif considered essential for the β‐defensin family. Each CjAvBDs also formed a sub‐group with the respective orthologous genes of various bird species in a phylogenetic tree analysis. Synteny between the CjAvBD cluster and GgAvBD cluster was confirmed. The CjAvBD cluster was mapped on the long‐arm end of chromosome 3 by linkage analysis based on single nucleotide polymorphisms (SNPs) of CjAvBD1 and CjAvBD12 (approximately 46kbp), as well as GgAvBD cluster. We also confirmed that CjAvBD1, ‐4, ‐5, ‐9, and ‐10 are transcribed in 20 tissues, including immune and digestive tissues. However, our experimental data indicated that the CjAvBD cluster lacks the AvBD3 and ‐7 loci, whereas the CjAvBD101α, ‐101β, and ‐101θ loci arose from gene duplication of the AvBD6 orthologous locus in the CjAvBD cluster after differentiation between Coturnix ‐ Gallus.     

Effects of diesel exhaust particles on the male reproductive system in strains of mice with different aryl hydrocarbon receptor responsiveness

Diesel exhaust particles (DEPs) contain polycyclic aromatic hydrocarbons (PAH) that bind to aryl hydrocarbon receptors (AhRs) and decrease sperm production. Since it is not clear if AhR mediates DEP toxicity, we investigated the effect of DEPs in four strains of mice that have different AhR responsiveness. We treated BALB/c, C57BL/6, ICR and DBA/2 mice with DEP suspensions and compared their toxicity in each strain. In both the vehicle- and DEP-treated groups, ethoxyresorufin-O-deethylase (EROD) activity, as an indirect index of AhR activity, was increased in the order of BALB/c > C57BL/6 > ICR > DBA/2. Only BALB/c and C57BL/6 mice had significantly lower daily sperm production (DSP) than vehicle-treated mice. All strains exhibited increased sperm abnormalities. In particular, the C57BL/6, ICR and DBA/2 mice exhibited significantly increased abnormalities. A significant correlation was found between EROD activity and DSP or incidence of morphologically abnormal sperm. These data suggest that DEP toxicity may affect the male reproductive system in an AhR-dependent manner.     

Growth Characteristics of Tea Plants and Tea Fields in Japan

In 12th century, the Buddhist priest Eisai brought tea ( Camellia sinensis L.) seeds to Japan from China and now tea plants are cultivated all over Japan except in the Hokkaido and Tohoku districts. The quality (reflected in the price) of Japanese green tea is affected by the nitrogen content. Consequently in tea fields, for last three decades large amounts of fertilizer have been applied to produce high quality tea. As a result, problems such as acidification of soil have been caused. It is also known that the growth of tea plants is stimulated by the addition of aluminum (Al) under acidic conditions. In this keynote address, some problems caused by excess applications of fertilizer in tea fields and the growth characteristics of tea plants related to Al are presented.     

Identification and phylogenetic analysis of Babesia parasites in domestic dogs in Nigeria

The present study examined the presence of Babesia parasites in 104 domestic dogs in Nigeria. Sequentially, Babesia parasites infecting domestic dogs underwent genetic and phylogenetic analyses. The results of nested PCR based on the Piroplasmida 18S rRNA gene illustrated that 13.5% (14/104) of the samples were positive. The obtained positive samples determined the nucleotide sequences of the 18S rRNA genes. In the genetic and phylogenetic analyses, four of five nucleotide sequences were similar to Babesia canis rossi, and one sample exhibited a close similarity to a Babesia sp. isolated from a raccoon in Hokkaido, Japan. The present study revealed the widespread presence of B. canis rossi among domestic dogs in Nigeria.     

Fine structure and differentiation of the alimentary canal in captive-bred Japanese eel Anguilla japonica preleptocephali

ABSTRACT:   The fine structure of the alimentary canal in preleptocephali produced by artificially matured Japanese eel was examined. At 1 day posthatch (dph), the alimentary canal was found only above the dorsal side of the yolk mass, and the epithelium was composed of a single layer of epithelial cells. By 5 dph, the alimentary canal was divided into three segments based on the structure of the epithelial cells: foregut, midgut and hindgut, corresponding to the future esophagus, intestine and rectum, respectively. After 7 dph, the epithelium in the foregut was surrounded by a circular muscle layer, suggesting a role in the transportation of food materials. The epithelial cells of the midgut exhibited well-developed membranous structures, which are deduced to be invaginations of the cytoplasmic membrane. Pinocytotic invaginations and vacuoles were observed in the epithelial cells of the hindgut; this observation suggests that this region is involved in the uptake of food. Significant changes in morphological features of the epithelial cells in each segment were observed until 7 dph; however, these were not evident between 7 dph and 13 dph. Consequently, the differentiation of the alimentary canal was completed by 7 dph, and preleptocephalus had developed the ability to absorb food by 7 dph.     

Iron uptake in a bicarbonate-resistant cell line of tobacco

Abstract

In alkaline soils, plant growth is impaired mainly by high pH and high concentration of bicarbonates. The bicarbonate concentration increases the pH value, and causes deficiency of iron. A bicarbonate-resistant cell line (BR line) of tobacco (Nicotiana tabacum L. cv. Burley21) was selected by adding excess bicarbonate ions (20 mmol L^?1) to the culture medium. The pH of the medium was buffered 8.0 to 8.3. Under these conditions, about 80% of iron in the medium became insoluble. However, under such conditions, the BR line grew well. In this report, we examined some characteristics of the growth and iron uptake in the BR line under iron-deficient (i.e. high pH or no-iron) condition. At pH 5.8, the Fe³⁺ reduction activity was not significantly different between the non-selected line and the BR line. At pH 8.0, however, the Fe³⁺ reduction activity of the BR line was higher than that of the non-selected line. In no-iron condition, the growth of the non-selected line was markedly reduced after 2 weeks, while the BR line was not affected. The content of malic acid in both lines increased with the medium pH, and the content in the BR line was higher than that in the non-selected line. The BR line was able to adapt to the conditions, which restricted iron uptake, such as high bicarbonate concentration, high pH, and low iron conditions. The high ability of Fe³⁺ reduction was maintained at even high pH conditions. Further, the BR line may be able to improve the utilization of iron in the cells.     

New severe strains of Melon necrotic spot virus: symptomatology and sequencing

New strains of Melon necrotic spot virus (MNSV), designated MNSV-YS and MNSV-KS, caused much more severe growth retardation on melon plants than MNSV-NH, which was previously reported as the most severe strain of MNSV in Japan. MNSV-YS spread much more quickly than MNSV-NH in infected plants, and induced more severe growth retardation, even though the appearance of necrotic lesions on inoculated cotyledons was much slower. MNSV-KS had properties intermediate between those of the other two strains. The results suggest that faster-spreading strains can multiply more rapidly as a result of lower levels of activity in inducing necrotic lesions in melon plants. The complete sequences of MNSV-YS and MNSV-KS were determined, and an RT–PCR–RFLP method based on these sequences was successfully developed to detect and discriminate between the three strains.