Multigenic system controlling viral systemic infection determined by the interactions between Cucumber mosaic virus genes and quantitative trait loci of soybean cultivars

Soybean 'Harosoy' is resistant to Cucumber mosaic virus soybean strain C (CMV-SC) and susceptible to CMV-S strain D (CMV-SD). Using enzyme-linked immunosorbent assay and Northern hybridization, we characterized the Harosoy resistance and found that CMV-SC did not spread systemically but was restricted to the inoculated leaves in Harosoy. Harosoy resistance was not controlled by either a dominant or recessive single gene. To dissect this system controlling long-distance movement of CMV in soybean, we constructed infectious cDNA clones of CMV-SC and CMV-SD. Using these constructs and the chimeric RNAs, we demonstrated that two viral components were required for systemic infection by the virus. The region including the entire 2b gene and the 5' region of RNA3 (mainly the 5' untranslated region) together were required. By quantitative trait locus (QTL) analysis using an F(2) population and the F(3) families derived from Harosoy and susceptible 'Nemashirazu', we also showed that at least three QTLs affected systemic infection of CMV in soybean. Our study on Harosoy resistance to CMV-SC revealed an interesting mechanism, in which multiple host and viral genes coordinately controlled viral systemic infection.     

Molecular cloning of interleukin-12 receptor beta2 chain and its expression in dogs

This study cloned canine interleukin-12 receptor beta2 (IL-12Rbeta2). Its nucleotide sequences were determined. Canine IL-12Rbeta2 showed 85.4% homology at the nucleotide level and 76.8% homology at the amino acid level with human IL-12Rbeta2. Its structural motifs were well conserved. We also cloned cDNA with a 91-bp deletion including the transmembrane region, which produced a frame shift and an early stop codon. Examination of the expression of deleted canine IL-12Rbeta2 mRNA revealed that both deleted and intact mRNAs were expressed at a constant ratio in all the dogs. Results suggested that expression of the deleted mRNA was constitutive and produced by alternative splicing.     

Spontaneous Malignant T Cell Lymphoma in a Young Male Common Marmoset (Callithrix jacchus)

We histopathologically and immunohistochemically investigated a case of malignant lymphoma that spontaneously developed in a male common marmoset at two years of age. Beginning at two years four months of age, the animal had an enlargement of the submandibular and inguinal lymph nodes, small subcutaneous nodules near the right breast and an approximately fivefold increase in peripheral lymphocyte count compared with the previous examination value. The postmortem findings at two years eight months of age showed lymphadenopathy with enlargement of the thymus and spleen. Small- to intermediate-sized neoplastic lymphocytes had diffusely proliferated in the enlarged nodes. The neoplastic cells were pleomorphic and had irregularly shaped nuclei. The nuclear chromatin staining revealed hyperchromatism in the small-sized cells, and the intermediate-sized cells exhibited vesicular staining. An immunohistochemical examination indicated that the neoplastic lymphocytes were positive for CD3 and negative for CD20, thus suggesting that they had originated from T cells. In addition, the proliferation of high endothelial venules and reactive epithelioid histiocytes was observed. Scattered tingible body-laden macrophages were infrequently detected. Neoplastic lymphocytes were also observed in the thymus, spleen, heart, lungs, liver, kidneys, adrenal glands and femoral and sternal bone marrow. This malignant lymphoma in a young male common marmoset was considered to fit the category of “peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS)” according to the new WHO system of classification.     

Development of a screening method for genetically modified soybean by plasmid-based quantitative competitive polymerase chain reaction

A novel type of quantitative competitive polymerase chain reaction (QC-PCR) system for the detection and quantification of the Roundup Ready soybean (RRS) was developed. This system was designed based on the advantage of a fully validated real-time PCR method used for the quantification of RRS in Japan. A plasmid was constructed as a competitor plasmid for the detection and quantification of genetically modified soy, RRS. The plasmid contained the construct-specific sequence of RRS and the taxon-specific sequence of lectin1 (Le1), and both had 21 bp oligonucleotide insertion in the sequences. The plasmid DNA was used as a reference molecule instead of ground seeds, which enabled us to precisely and stably adjust the copy number of targets. The present study demonstrated that the novel plasmid-based QC-PCR method could be a simple and feasible alternative to the real-time PCR method used for the quantification of genetically modified organism contents.     

Characteristic Variation of Concentration and Chemical Form in Sulfur, Nitrate, Ammonium, and Chloride Species Observed at Urban and Rural Sites of Japan

A field survey on the concentration of chemical species in particulate matter and gaseous compounds at two monitoring sites with different site classifications (urban and rural) was conducted over three years. Total (particulate matter + gaseous compounds) concentrations at the rural site were significantly lower than those at the urban site for all species (sulfur $\left( {{\text{SO}}^{{{\text{2 - }}}}_{{\text{4}}} {\left( {\text{p}} \right)}} \right.$ and SO₂(g)), nitrate ${\text{(NO}}_{{{\text{3}}^{{\text{ - }}} }} {\left( {\text{p}} \right)}$ and HNO₃(g)), ammonium ${\text{(NH}}_{{{\text{4}}^{{\text{ + }}} }} {\text{(p)}})$ and ammonia (NH₃(g)), and chloride (Cl^? (p) and HCl (g))), which is thought to reflect classification of the site. The difference in the sulfur concentration at the urban and rural sites was characterized by the difference in SO₂ (g) concentration. Further, a clear seasonality was observed for the nitrate species. The HNO₃ (g) concentration was high in the summer compared with other seasons at both the urban and rural sites. The ${\text{NH}}_4^ + \left( {\text{p}} \right)$ concentration levels were approximately the same as those of NH₃ (g) at both sites. The molar ratios of the particulate matter concentration to the total concentration showed different characteristics; the nitrate, ammonium and ammonia, and chloride species showed a clear seasonal variation: low in summer and high in winter and the values were similar regardless of the site. On the other hand, the sulfur species showed constant values at both the urban and rural sites, however the concentrations were significantly different for the two sites. Ammonium accounted for the largest proportion of cations in the particulate matter, regardless of the site classification. In contrast, ${\text{SO}}_4^{2 - } \left( {\text{p}} \right)$ accounted for the largest proportion of anions at the rural site, whereas ${\text{NO}}_3^ - \left( {\text{p}} \right)$ was comparable to ${\text{SO}}_4^{2 - } \left( {\text{p}} \right)$ at the urban site. Ammonia accounted for the largest proportion of all chemical species at both sites. Seasonal analysis of the proportional distribution in particulate matter and gaseous compounds provides information on atmospheric conditions.     

Anther culture in rice proportionally rescues microspores according to gametophytic gene effect and enhances genetic study of hybrid sterility

Background

To investigate plant hybrid sterility, we studied interspecific hybrids of two cultivated rice species, Asian rice (Oryza sativa) and African rice (O. glaberrima). Male gametes of these hybrids display complete sterility owing to a dozen of hybrid sterility loci, termed HS loci, but this complicated genetic system remains poorly understood.

Results

Microspores from these interspecific hybrids form sterile pollen but are viable at the immature stage. Application of the anther culture (AC) method caused these immature microspores to induce callus. The segregation distortion of 11 among 13 known HS loci was assessed in the callus population. Using many individual calli, fine mapping of the HS loci was attempted based on heterozygotes produced from chromosome segment substitution lines (CSSLs). Transmission ratio distortion (TRD) from microspores was detected at 6 of 11 HS loci in the callus population. The fine mapping of S₁ and S₁₉ loci using CSSLs revealed precise distances of markers from the positions of HS loci exhibiting excessive TRD.

Conclusions

We demonstrated that AC to generate callus populations derived from immature microspores is a useful methodology for genetic study. The callus population facilitated detection of TRD at multiple HS loci and dramatically shortened the process for mapping hybrid sterility genes.

     

Preparation of Photocrosslinked Fish Elastin Polypeptide/Microfibrillated Cellulose Composite Gels with Elastic Properties for Biomaterial Applications

Photocrosslinked hydrogels reinforced by microfibrillated cellulose (MFC) were prepared from a methacrylate-functionalized fish elastin polypeptide and MFC dispersed in dimethylsulfoxide (DMSO). First, a water-soluble elastin peptide with a molecular weight of ca. 500 g/mol from the fish bulbus arteriosus was polymerized by N,N′-dicyclohexylcarbodiimide (DCC), a condensation reagent, and then modified with 2-isocyanatoethyl methacrylate (MOI) to yield a photocrosslinkable fish elastin polypeptide. The product was dissolved in DMSO and irradiated with UV light in the presence of a radical photoinitiator. We obtained hydrogels successfully by substitution of DMSO with water. The composite gel with MFC was prepared by UV irradiation of the photocrosslinkable elastin polypeptide mixed with dispersed MFC in DMSO, followed by substitution of DMSO with water. The tensile test of the composite gels revealed that the addition of MFC improved the tensile properties, and the shape of the stress–strain curve of the composite gel became more similar to the typical shape of an elastic material with an increase of MFC content. The rheology measurement showed that the elastic modulus of the composite gel increased with an increase of MFC content. The cell proliferation test on the composite gel showed no toxicity.     

Winter nitrate uptake by the temperate deciduous tree <Emphasis Type="Italic">Quercus serrata</Emphasis>

Winter nitrogen use in deciduous species is largely uncharacterized. We investigated nitrate uptake in the fine roots of a deciduous oak (Quercus serrata Thunb. ex. Murray). We conducted a ¹⁵N-labeling experiment using saplings of Q. serrata in the winter. During three weeks of labeled nitrate application, the concentration of ¹⁵N in the fine roots increased significantly. The amount of nitrogen absorbed, as nitrate, was 1.16 ± 1.02 mg N g DW⁻¹, equivalent to 7.6 ± 5.8% of the total nitrogen content. Our results indicate that Q. serrata saplings have significant potential for nitrate uptake in the fine roots in midwinter (i.e., in the absence of leaves). Although a significant amount of nitrogen applied as nitrate was accumulated, nitrate concentration in the fine roots remained low during the labeling period. Furthermore, significant nitrate reductase activity was detected. These data suggest that Q. serrata saplings can assimilate nitrate in the fine roots in midwinter.     

Purulent Necrotic Dislocation of the Hip Joint Associated with Umbilical Infection in a Foal

A 42-day-old heavy draft horse fell into sudden astasia. Significant swelling and heat sensation of the left femoral region were observed. Because of a friction sound in the left hip, we supposed that the hip joint was dislocated or the hip bone was fractured. Computed Tomography (CT) examination showed that the left hip joint was dislocated and the left femoral head was disjunct. We carried out a pathological autopsy, and made a diagnosis of the foal as fracture of the hip bone and femoral head with suppurative umbilical arteritis. Pathologic changes in the umbilical artery and hind leg were completely unilateral, suggesting that left umbilical arteritis spread to the blood circulation, causing arthritis and dislocation of the hip bone.