Detection and sequence analysis of DNA polymerase and major envelope protein genes in koi herpesviruses derived from Cyprinus carpio in Gunma prefecture, Japan

Koi herpesvirus (KHV), which is believed to be an emerging virus, causes fatal diseases in carps. Since the 1990s, the presence of KHV has been confirmed in several countries. In Japan, from 2003 to 2004, large outbreaks of KHV infection in farmed carps resulted in the death of numerous fishes. From April to May 2004, we collected 43 dead or dying carps exhibiting typical symptoms of KHV infection in Gunma prefecture. To conduct a molecular epidemiologic study of KHV in our prefecture, we amplified DNA polymerase and the major envelope protein genes of KHV derived from carp gills using newly designed primers. We also performed sequence analysis of both genes of KHV. Sensitivity of our PCR method for amplification of DNA polymerase and the major envelope protein genes of KHV was 3 x 10(2) (100 fg) and 3 x 10(3) (1000 fg) copies of KHV genome, respectively. We detected both DNA polymerase and major envelope protein genes in 37 of 43 carps (86%). No mutation was found in both the genes sequenced from 11 strains, which included two foreign strains and one domestic strain. The results suggested that KHV strains derived from carps in our prefecture were closely related genetically to the other KHV strains.     

The g.841G>C SNP of FASN gene is associated with fatty acid composition in beef cattle

The objective of the current study is to evaluate the association between fatty acid composition and fatty acid synthase gene polymorphisms as responsible mutations. For this purpose, we selected seven previously reported single nucleotide polymorphisms (SNPs) in FASN gene, including one within promoter region (g.841G>C) and six non‐synonymous SNPs (g.8805C>T, g.13126C>T, g.15532A>C, g.16024A>G, g.16039C>T, g.17924A>G), and genotyped them in Japanese Black cattle. Genotyping results revealed that g.8805 C>T and g.17924 A>G were monomorphic loci. Genome‐wide association analysis including the other five SNPs revealed that only g.841G>C showed significant associations with the percentages of C14:0, C14:1, C16:1 and C18:1 at 5% genome‐wide significance level. In order to further evaluate the effect, we genotyped g.841G>C using additional three populations, including two Japanese Black populations and a Holstein cattle population. g.16024A>G was also genotyped and included in the analysis because it has been reported to be associated with fatty acid composition in Japanese Black cattle. In the result of analysis of variance, g.841G>C showed stronger effects on fatty acid percentage than those of g.16024A>G in all populations. These results suggested that g.841G>C would be a responsible mutation for fatty acid composition and contribute to production of high‐grade beef as a selection marker in beef cattle.     

Effect of calcined lime (CaO) on chlamydospores of the rice false smut pathogen,Villosiclava virens,and their root attachment and infection

Rice false smut caused by Villosiclava virens is a devastating disease. The smut balls contain chlamydospores, which fall onto paddy soils to become the primary inoculum. After transplanting, the chlamydospores subsequently germinate and infect rice roots. The application of a CaO-containing fertilizer to paddy soils can inhibit the development of rice false smut disease; however, the underlying mechanism is unknown. In this study, we evaluated the suppression of chlamydospore behaviour due to CaO. Specifically, we clarified the effects of the following on chlamydospore morphology and germination: (a) pH, (b) calcium (Ca) concentration, (c) Ca concentration (pH adjusted to 6.5), and (d) CaO-added soil solution. Germination was suppressed at pH 4 and 10, in contrast with the normal germination at pH 6, 7, and 8. Treatments with more than 10 mg/L Ca melted the outer layer of chlamydospores and suppressed germination regardless of whether the pH was adjusted to 6.5. A saturated CaO solution induced bursting of chlamydospores. Suppressed germination and a melted outer chlamydospore layer were also observed, even though the soil buffering effect initially prevented the CaO-mediated pH increase. Furthermore, the chlamydospores within 15 mm from the CaO small lump exhibited suppressed germination in soil. In addition, there was no effect of CaO treatment on chlamydospore attachment to rice roots and hyphal invasion of rice roots in in vitro inoculation tests. These results suggest that Ca concentration is an important factor for inhibiting the occurrence of rice false smut disease.     

Structural conservation of the <Emphasis Type="Italic">hrp</Emphasis> gene cluster in <Emphasis Type="Italic">Xanthomons oryzae</Emphasis> pv. <Emphasis Type="Italic">oryzae</Emphasis>

The clustered hrp genes encoding the type III secretion system in the Japanese strains MAFF301237 and MAFF311018 of Xanthomonas oryzae pv. oryzae were sequenced and compared. The strains differ in their pathogenicity, location, and year of isolation. A 30-kbp sequence comprising 29 open reading frames (ORFs) was identical in its structural arrangement in both strains but differed from X. campestris pv. campestris, X. axonopodis pv. citri, and X. axonopodis pv. glycines in certain genes located between the hpaB-hrpF interspace region. The DNA sequence and the putative amino acid sequence in each ORF was also identical in both X. oryzae pv. oryzae strains as were the PIP boxes and the relative sequences. These facts clearly showed that the structure of the hrp gene cluster in X. oryzae pv. oryzae is unique.     

Omental herniation through the esophageal hiatus in a cat

A four-year-old male cat was presented with regurgitation. Thoracic radiography and contrast radiogram showed a large oval mass and elevated esophagus. Exploratory thoracotomy showed omental herniation into the posterior mediastium through the esophageal hiatus. Because the mass of the omental herniation was so large, celiotomy through a paracostal incision was combined in order to return the omentum to its normal position. The diameter of the esophageal hiatus was approximately 1 cm but no fibrous adhesion was observed around the hiatus. Continuous 1-0 surgical sutures on the hiatus reduced the diameter of the hiatus. The cat made a successful postoperative recovery without complications.     

Bioactive Alkaloids from the Sea: A Review

In our ongoing search for bioactive substances from marine organisms, novel alkaloids have been isolated. Pinnatoxins and pinnamine, potent shellfish poisons, were purified from the Okinawan bivalve Pinna muricata. Pinnatoxins activate Ca²⁺ channels. Halichlorine was isolated from the marine sponge Halichondria okadai. This compound inhibits the induction of VCAM-1. Drugs that block VCAM-1 may be useful for treating coronary artery diseases, angina, and noncardiovascular inflammatory diseases. Pinnaic acids, which are cPLA₂ inhibitors, were also obtained from P. muricata. Interestingly, the structures of pinnaic acids are closely related to that of halichlorine. Norzoanthamine hydrochloride, isolated from the colonial zoanthid Zoanthus sp., suppresses decreases in bone weight and strength in ovariectomized mice, and could be a good candidate for an osteoporotic drug. Ircinamine, purified from the marine sponge Ircinia sp., has a reactive thioester. Aburatubolactams, inhibitors of superoxide anion generation, were isolated from Streptomyces sp. This article covers the bioactive marine alkaloids that have been recently isolated by this research group.     

Quantitative structure-activity relationships of light-dependent herbicidal 4-pyridone-3-carboxanilides III. 3-D (comparative molecular field) analysis including light-dependent diphenyl ether herbicides

Using a set of representative members selected from 4-pyridone-3-carboxanilides and ortho-chlorinated diphenyl ethers exhibiting light-dependent herbicidal activity, we examined the three-dimensional structure-activity relationships quantitatively. The most stable conformation of each compound, regarded as the ‘active conformation’, was determined by either semi-empirical or ab initio molecular orbital calculations. With a hypothesis defining a common substructural skeleton between the two different compound series. each molecule was superimposed. We first analysed the structure-activity relationship using an index for the substructure shape similarity according to the superimposed conformations. After finding the relevance of the hypothesis, we examined the three-dimensional structure-activity relationship using the comparative molecular field analysis procedure. The results suggested that the two different series of compounds have a common region of the receptor site. The variations in the light-dependent herbicidal potency were governed by hydrophobicty and three-dimensional steric and electronic field parameters of molecules participating in the transport process and the interaction with the receptor site. The result was consistent with that derived from our previous quantitative analysis with the use of free-energy-related substituent parameters and the traditional regression procedure for a large number of pyridone-carboxanilides.     

Spin disorder on a triangular lattice

As liquids crystallize into solids on cooling, spins in magnets generally form periodic order. However, three decades ago, it was theoretically proposed that spins on a triangular lattice form a liquidlike disordered state at low temperatures. Whether or not a spin liquid is stabilized by geometrical frustration has remained an active point of inquiry ever since. Our thermodynamic and neutron measurements on NiGa2S4, a rare example of a two-dimensional triangular lattice antiferromagnet, demonstrate that geometrical frustration stabilizes a low-temperature spin-disordered state with coherence beyond the two-spin correlation length. Spin liquid formation may be an origin of such behavior.     

Formaldehyde Concentrations in Ambient Air in Urban and Rural Areas in Gunma Prefecture, Japan

We measured formaldehyde concentrations in ambient air at urban (Isesaki) and rural (Annaka) sites in Gunma Prefecture, Japan from June 1998 to March 2003. Measurements were carried out once in a month to obtain daily mean formaldehyde concentrations. At both the sites, mean concentrations of formaldehyde were significantly higher from April to September (summer) than from October to March (winter). Formaldehyde concentrations in Annaka were essentially as high as those in Isesaki in summer, but were significantly lower in winter. At both the sites, concentrations of formaldehyde and oxidants correlated significantly with one another in the summer; correlation coefficients in Annaka and Isesaki were 0.82 and 0.64, respectively. The fraction of formaldehyde formed photochemically based on concentrations of benzene was calculated to be as high as 80% in both the sites in summer. The results suggested that formaldehyde concentrations were high even in rural air, reflecting photochemical reactions rather than automobile exhaust.