Structural gene and strain specificity of a novel cysteine protease produced by Staphylococcus aureus isolated from a diseased chicken

Recently whole genome sequencing of Staphylococcus aureus has revealed the genes encoding cysteine proteases such as staphopain and SspB. In this study, we cloned and sequenced the structural gene (ScpA) encoding a cysteine (thiol) protease of S. aureus strain CH-91 from a chicken with dermatitis using polymerase chain reaction (PCR) and inverse PCR methods. The sequence information revealed a coding sequence (CDS) of 1200 nucleotides encoding the ScpA preproenzyme of 399 amino acids with a molecular mass of 45,071 Da. The deduced amino acid sequence of the ScpA differed at many positions from those of staphopain and SspB with identities of 64 and 42%, respectively. In the Southern blot analysis with a total DNA of S. aureus strain CH-91, the ScpA probe hybridized with a single 7.7 kb XbaI fragment or 2.8 and 0.8 kb EcoRI fragments, whereas the staphopain and SspB probes did not hybridize with these DNA fragments. These results suggest that this ScpA gene is a single-copy gene and is a novel gene, which is not found in the published whole genome sequences of S. aureus. In immunoblot, PCR, and Southern blot assays, the ScpA or its gene was detected in high protease-producing strains from chickens, but was not recognized in bovine and porcine strains or low protease-producing avian strains. These results indicate that the ScpA of CH-91 type may be specific to the high protease-producing strains of S. aureus from chickens, namely, there is a strain specificity of the ScpA.     

A meningioma with hyperintensity on T1-weighted images in a dog

A male six-year-old Pomeranian showed recurrent seizures and progressive left hemiparesis. MRI revealed a mass in the right paramedian frontal-temporal region with hyperintensity on T1-weighted (T1W) and mixed-intensity on T2-weighted (T2W) images. After gadolinium enhancement, the mass was enhanced homogenously and demonstrated the dural tail sign. Surgical resection of mass was performed and its histological diagnosis was meningioma. The meningioma of this case had a high cellular density with some lipid contents and intra- and extra-tumor hemorrhage, however, calcification was not found. These cellular characteristics may contribute to a higher signal intensity on T1W imaging.     

Immunohistochemical distribution of inwardly rectifying K+ channels in the medulla oblongata of the rat

The inwardly rectifying K+ channels, Kir1.1, Kir2.3 and Kir4.1-Kir5.1, are the candidate chemosensory molecules for CO2/H+. We determined the mRNA expression and immunohistochemical localization of these channels in the medulla oblongata of the rat. RT-PCR analysis revealed mRNAs of Kir1.1, Kir2.3, Kir4.1 and Kir5.1 were detected in the medulla. The immunoreactivities for Kir1.1, Kir2.3, Kir4.1, and Kir5.1 were observed in the medulla, and immunolabeling pattern was varied by the subunit. Immunoreactivities for Kir1.1 and Kir2.3 were observed in the nerve cell bodies and glial cells both in the chemosensory areas [nucleus tractus solitarius (NTS), nucleus raphe obscurus (RO), pre-B?tzinger complex (PreB?tC)] and non-chemosensory area [hypoglossal nucleus (XII), inferior olive nucleus (IO)]. Kir4.1 immunoreactivity was observed in the glial cells and neuropil, especially in XII and IO. Kir5.1 immunoreactivity was observed in the nerve cell bodies in the XII, RO, and PreB?tC, but not in the NTS or IO. In the NTS, a dense network of varicose nerve fibers showed immunoreactivity for Kir5.1. Our findings suggest that Kir channels may not act specific to the central chemoreception, but regulate the ionic properties of cellular membranes in various neurons and glial cells.     

Water productivity of contrasting rice genotypes grown under water-saving conditions in the tropics and investigation of morphological traits for adaptation

Alternate wetting and drying (AWD) irrigation in lowland rice has been successfully implemented in farmers’ fields to reduce water input, and thereby increasing water productivity. Reported effects on grain yield were, however, contradictory: yield was reduced, maintained, or even increased when compared with continuously flooded (CF) conditions. This study was conducted in heavy clay soil to investigate yield variation among a range of genotypes grown under AWD and to determine some aboveground traits related to crop adaptation. The effect of AWD on grain yield, with a critical threshold of soil water potential for irrigation fixed at −30 kPa, varied among the 10 genotypes evaluated. Two adapted genotypes were identified with similar grain yield under CF and AWD in both experimental seasons. The grain yield of the aerobic-adapted cultivar included in the study was also maintained under AWD, however, its yield was comparatively low. The reduction in grain yield of the non-adapted genotypes ranged from 9 to 13% in the 2006 dry season and from 6 to 17% in the 2008 dry season. None of the yield components could explain by itself the variability in genotype response: in adapted genotypes, grain yield was maintained because of compensation from or maintenance of yield components, whereas, in non-adapted genotypes, grain yield reduction was not due to the decrease of one component only. Modified biomass partitioning appeared as a main driver for adaptation to AWD: adapted genotypes were characterized by larger sink size at flowering, and weaker stems and less unfilled grain number at maturity, suggesting an increase in the sink strength of the filling spikelets. The aboveground traits identified here will be of great help to further increase water productivity under the AWD strategies set up previously by IRRI water scientists.     

Retrospective study on the outcomes and risk factors of right paramedian abomasopexy for right abomasal disorders in 47 dairy cows

Very few epidemiologic studies have verified the utility of the right paramedian abomasopexy (RPA) technique in cows with right abomasal disorders. This study aimed to investigate the outcomes and risk factors for non-survival in the herd within 30 days of surgery in cows with right abomasal disorders who underwent the RPA technique. Forty-seven Holstein cows with right abomasal disorders (25 with right abomasal displacement [RDA] and 22 with right abomasal volvulus [RAV]) were included. Twenty-two cows with RDA (22/25, 88.0%) and 10 cows with RAV (10/22, 45.5%) survived at 30 days post-surgery. Multivariate logistic regression analysis indicated that hyponatremia, hypokalemia, and the presence of abomasal volvulus were the major risk factors associated with non-survival.     

Contrasting biomass,dynamics and diversity of microbial community following the air-drying and rewetting of an upland and a paddy soil of the same type

We report a preliminary investigation into soil microbial biomass C, ATP, microbial community composition and gaseous emissions when an upland Chinese and an immediately adjacent paddy soil were incubated with increasing percentage water holding capacities (WHC) from 10% WHC to waterlogging for 10 days. The aim was to see what adaptations, if any, occur when a paddy soil is incubated under conditions of increasing soil moisture, from 10% WHC to waterlogging and an adjacent upland soil is subjected to the opposite moisture changes, from waterlogging to 10% WHC. The main differences were that soil ATP remained quite constant in the paddy soil, irrespective of the different WHCs while in the upland soil, it increased from a low level between 10 and 20% WHC to a maximum at 60% WHC declining to a similar low level as 10 and 20% when waterlogged. The most striking feature was that although there were significant changes in biomass C, ATP and biomass ATP concentrations, of up to 3-fold or more, due to changing soil moisture, the changes in relative abundance of the microbial community composition measured by gene sequencing, particularly for fungi, were small and often insignificant, especially between 40% WHC and waterlogging. There were significant changes in bacterial community composition between 10 and 40%, where 45 to 61% of bacteria responded to the change. However, the changes were very few between 40% WHC and waterlogging. Thus, there was no clear link between the large changes in microbial biomass and microbial community composition.     

秸秆条带状覆盖对稻田CH_4和N_2O排放的影响

采用3种秸秆还田方式(对照、秸秆均匀混施和秸秆条带状覆盖)进行田间试验,观测稻田CH4和N2O的排放通量,以探讨秸秆条带状覆盖对稻田CH4和N2O排放的影响。结果表明:秸秆条带状覆盖的CH4排放量是对照的2.7倍,二者的N2O排放量无明显差异;秸秆条带状覆盖的稻田CH4排放量较秸秆均匀混施减少32%,其N2O排放量是后者的5.1倍;稻田排放CH4和N2O的全球增温潜势(GWP)为:秸秆均匀混施秸秆条带状覆盖对照,且差异显著;秸秆条带状覆盖的水稻产量分别较对照和秸秆均匀混施增加27%和17%。秸秆条带状覆盖是值得推荐的稻季秸秆还田方式。     

Measurement of ammonia volatilization loss using a dynamic chamber technique: A case study of surface-incorporated manure and ammonium sulfate in an upland field of light-colored Andosol

The present study aimed to elucidate ammonia (NH₃) volatilization loss following surface incorporation (0–15 cm mixing depth) of nitrogen (N) fertilizer in an upland field of light-colored Andosol in central Japan. A dynamic chamber technique was used to measure the NH₃ effluxes. Poultry manure, pelleted poultry manure, cattle manure, pelleted cattle manure and ammonium sulfate were used as N fertilizers for basal fertilization to a bare soil with surface incorporation. All three experiments in summer and autumn 2007 and in summer 2008 showed negligible NH₃ volatilization losses following the application of all N fertilizers with the same application rate of 120 kg N ha⁻¹ as total N; these negligible losses were primarily ascribed to chemical properties of the soil, that is, its high cation exchange capacity (283 mmol_c kg⁻¹ dry soil) and relatively low pH(H₂O) (5.9). In addition, the surface incorporation, the very small ratio of ammoniacal N to total N for the manure, and the decrease in soil pH to ≤5.5 following applications of ammonium sulfate were also advantageous to the inhibition of NH₃ volatilization loss from the field-applied N fertilizers.     

Properties of Microbial Biomass in Acid Soils and Their Turnover

The soil microbial biomass is important such as pool of plant nutrients and is also driving force of the cycling of C, N, P and S in soil. However, the microbial biomass in acid soil has not been fully investigated due to the limitation of methods, i.e. chloroform-fumigation incubation or substrate-induced respiration because of decreased basal mineralization in chloroform-fumigated soil under acid conditions. This paper reviews improvement and application of these methods and vertical distribution of microbial biomass in two kinds of acid soils; namely, Andisols as dominant upland soils in Japan and tropical peat soils as potentially important lowland soils for agriculture, and also discuss on C and N turnover of microbial biomass in Andisols. Microbial succession in acid soil has also not been investigated so much, but, some studies in another important acid soil, i.e. acid sulfate soil, were also reviewed briefly.     

普通野生稻和亚洲栽培稻核基因组的RFLP分析

 本研究通过对来自亚洲10个国家的122份普通野生稻（O.rufipogon Griff.，简称普野，下同）和76份亚洲栽培稻（O.sativa L.）的核DNA RFLP分析，探讨了中国普野与南亚、东南亚普野，普野与栽培稻以及籼粳之间的遗传分化关系。结果表明，籼粳分化是栽培稻核DNA遗传分化的主流。在核DNA分化上，中国普野可分为原始普野型，偏籼型和偏粳型；南亚普野只有原始普野型和偏籼型，没有偏粳型；东南亚普野有原始普野型和偏籼型，还可能有偏粳型。中国普野因地理分布不同，其遗传分化表现出多态性，江西东乡和湖南茶陵以及部分云南元江普野既不与籼稻聚在一起，又不与粳稻聚在一起，而独聚一类，其形态上亦比较原始，属于原始祖先型。广东、广西普野则表现为偏籼或偏粳。根据中国、南亚、东南亚普野的遗传分化关系，再次论证了中国和南亚（以印度为中心）是栽培稻起源演化的两个原始中心，并提出了籼粳演化应该是多途径的。