Demonstration of the absence of intervening sequences (IVSs) within 16S rRNA genes of Taylorella equigenitalis and Taylorella asinigenitalis isolates

A total of 57 Taylorella equigenitalis (n=22) and Taylorella asinigenitalis (n=35) isolates was shown not to carry any intervening sequences (IVSs) within 16S rRNA gene sequences. By contrast, we have already shown the genus Taylorella group to carry several kinds of IVSs within the 23S rRNA gene sequences.     

Colonization of the vegetative stage of rice plants by the false smut fungus Villosiclava virens,as revealed by a combination of species‐specific detection methods

Rice false smut disease caused by the ascomycete fungus Villosiclava virens (Clavicipitaceae) reduces rice yield worldwide. It invades rice panicles and forms dark‐green false smut balls composed of thick‐walled conidia. Although the infection process during the booting stage is well studied, its infection route before this is unclear. It was hypothesized that the thick‐walled conidia in soil penetrate rice roots, and the fungus latently colonizes roots and tiller buds at the vegetative stage. This hypothesis was tested using species‐specific detection methods. First, real‐time PCR with species‐specific primers and probe was used to estimate thick‐walled conidial number in the paddy field soil. Secondly, nested PCR with species‐specific primers showed that fungal DNA was detected in roots and shoot apices of rice plants in the vegetative stage. Thirdly, colourimetric in situ hybridization with a species‐specific oligonucleotide probe targeting 18S rRNA suggested that sparse mycelia or tightly condensed mycelia were present on the external surface of tiller buds enveloped by juvenile leaf sheaths at the vegetative stage. Thin hyphae were found around leaf axils at the surface of elongated stems at the heading stage, and the fungal hyphae grew in the rice root tissues. In addition, it was demonstrated that eGFP‐tagged transformants of the fungus invaded rice roots and colonized the surface of roots and leaf sheaths under artificial conditions.     

Pulmonary adenocarcinoma with osteoblastic bone metastases in a cat

A 12-year-old male cat with depression and dyspnoea was presented for investigation. Radiography and computed tomography revealed hydrothorax and solid masses involving the sternum, ribs and thoracic vertebrae. The cat died two days after first presentation, and postmortem examination revealed lung masses and proliferative bony lesions. Histologically, a neoplastic proliferation of epithelial cells was seen in the lungs, with a large amount of collagen and deposits of cholesterin. The bone lesions were also composed of neoplastic epithelial cells and abundant calcified osteoid, without atypia. A diagnosis of pulmonary adenocarcinoma with osteoblastic bone metastases was made. This is the first reported case of osteoblastic metastases in the cat.     

Specific cell-mediated immunity in fish

This review describes the fish immune system, focusing on specific cell-mediated immunity. Specific in vivo cell-mediated immune responses have been shown by allograft rejection, graft-versus-host reaction (GVHR) and delayed hypersensitivity reaction (DTH). Recent in vitro studies also showed specific cell-mediated cytotoxicity against allogeneic target cells. These in vivo and in vitro experiments strongly suggest the presence of cytotoxic T cells in fishes. Also described are current studies on shark and trout MHC class I polymorphism and function that demonstrate strong similarities between fish and mammals.     

Survey of Cryptosporidium spp. and Giardia spp. infections in various animals at a zoo in Japan.

A total of 284 fecal samples of 89 species (43 mammalian species and 46 avian species) were examined for Cryptosporidium oocysts and Giardia cysts from 1999 to 2002. Each sample was collected at the zoo located at Osaka in Japan and examined by microscopy after performing the sucrose flotation method and by two immunofluorescent assay kits for detection of Cryptosporidium oocysts and Giardia cysts. Cryptosporidium spp. was found only in a raccoon dog (Nyctereutes procyonoides), and Giardia spp. was detected in a mandarin duck (Aix galericulata) and two ruddy shelducks (Tadorna ferruginea). In this study, the prevalences of these parasites were found to be low. However, these results suggested that the infected animals could serve as a source of contamination for surface water. This is the first report about the survey of Cryptosporidium spp. and Giardia spp. at a zoo in Japan.     

Overexpression of the Barley Nicotianamine Synthase Gene HvNAS1 Increases Iron and Zinc Concentrations in Rice Grains

In humans, iron (Fe) and zinc (Zn) deficiencies result in major worldwide health problems. Transgenic technologies to produce Fe- and Zn-biofortified rice varieties offer a promising potential solution. Nicotianamine, the precursor of phytosiderophores, chelates Fe²⁺ and Zn²⁺ and plays an important role in transporting these metals to both vegetative and reproductive organs within the plant. Our objective was to increase Fe and Zn contents in rice grains by overexpressing the barley nicotianamine synthase gene HvNAS1. HvNAS1-overexpressing transgenic rice showed increased HvNAS1 expression and subsequent increases in endogenous nicotianamine and phytosiderophore content in shoots, roots, and seeds. Fe and Zn concentrations in polished T₁ seeds from transgenic plants increased more than three and twofold, respectively; Fe and Zn concentrations also increased in both polished and brown T₂ seeds. These results suggest that the overproduction of nicotianamine enhances the translocation of Fe and Zn into rice grains.     

Adverse and beneficial effects of long-term high-concentration ascorbic acid supplementation in rainbow trout <Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>

The present study examined the effects of high-concentration ascorbic acid (AsA) supplementation over a long period on growth, plasma components, nonspecific immune responses, and thermal tolerance in rainbow trout Oncorhynchus mykiss. Four commercial diets supplemented with 0, 100, 1000, and 5000 mg AsA per kg of diet (designated AsA0, AsA100, AsA1000, and AsA5000, respectively) were fed to rainbow trout (initial weight 1.85 g) for 100 days. AsA contents in liver increased with increasing dietary AsA levels. Feeding period, growth performance, and plasma components did not differ significantly between the AsA groups. On the other hand, the phagocytic assay [nitro-blue tetrazolium (NBT) assay] was significantly higher in fish fed AsA1000 and AsA5000 than those fed a diet without AsA (AsA0) at the end of feeding trial. Superoxide dismutase (SOD) activity in the intestines of fish fed AsA5000 was also significantly higher than that of fish fed AsA0. In the thermal tolerance test, fish fed AsA5000 only showed significantly lower cumulative mortality compared with the AsA0 group. In conclusion, high-concentration AsA supplementation such as AsA5000 over a long period does not induce any adverse effects and can enhance disease and stress resistance in rainbow trout.     

Wild stock structure of <Emphasis Type="Italic">Girella punctata</Emphasis> in Japan revealed shallow genetic differentiation but subtle substructure in subsidiary distributions

Twelve populations of Girella punctata, from widespread locations of the species’ range in Japan and Korea, were screened for sequence variability within the mitochondrial DNA (mtDNA) control region (n = 128) and at five polymorphic microsatellite loci (n = 547) to determine the genetic structure maintaining population integrity. mtDNA variability of 132 variable sites within a 334-bp region reveals shallow genetic differentiation across populations. The weak differentiation of G. punctata was partly supported by the screening of five polymorphic microsatellite loci. However, hierarchical analysis of molecular variance and principal component analysis on the basis of allele frequencies in microsatellite loci extracted a subtle substructure in a subsidiary population and in near-subsidiary populations in the semi-enclosed Seto Inland Sea.     

Variation of fruiting body productivity in protoplast fusants between compatible monokaryons ofLentinula edodes

Mycelial protoplasts of two compatible monokaryons ofLentinula edodes were prepared, and electro-fusion was undertaken. Sixteen dikaryons isolated after the electrofusion were tested for their fruiting abilities in comparison to the two dikaryons obtained by reciprocal mycelial mating. There were significant differences in fruiting body yield among the fusants, and some of them produced more fruiting bodies than did normally mated dikaryons. Although these dikaryons were divided into five genetically different groups by isozyme analyses and a cluster analysis, we could not find clear differences among the groups in terms of fruiting body yield, mycelial growth rate, or degree of wood decay. It appeared that fruiting body yield correlated positively with the mycelial growth rate but negatively with the degree of wood decay.