Applicability of Aegilops tauschii drought tolerance traits to breeding of hexaploid wheat

Few genes are available to develop drought-tolerant bread wheat (Triticum aestivum L.) cultivars. One way to enhance bread wheat’s genetic diversity would be to take advantage of the diversity of wild species by creating synthetic hexaploid wheat (SW) with the genomic constitution of bread wheat. In this study, we compared the expression of traits encoded at different ploidy levels and evaluated the applicability of Aegilops tauschii drought-related traits using 33 Ae. tauschii accessions along with their corresponding SW lines under well-watered and drought conditions. We found wide variation in Ae. tauschii, and even wider variation in the SW lines. Some SW lines were more drought-tolerant than the standard cultivar Cham 6. Aegilops tauschii from some regions gave better performing SW lines. The traits of Ae. tauschii were not significantly correlated with their corresponding SW lines, indicating that the traits expressed in wild diploid relatives of wheat may not predict the traits that will be expressed in SW lines derived from them. We suggest that, regardless of the adaptability and performance of the Ae. tauschii under drought, production of SW could probably result in genotypes with enhanced trait expression due to gene interactions, and that the traits of the synthetic should be evaluated in hexaploid level.     

评价大米储藏品质的炊饭特性指标的研究

提出了评价大米储藏品质的炊饭特性新指标——光透过率差。实验证明，随着大米品质的劣化，光透过率差明显变小。以此指标为主，结合原有的加热吸水率和ｐＨ值，对因生霉和陈化引起的大米储藏品质的变化，都能较好地进行评价。同时对影响这些指标稳定的实验因素也进行了探讨。     

Characterization of bullet tuna myoglobin with reference to the thermostability-structure relationship

Myoglobin (Mb) was isolated from bullet tuna (Auxis rochei) skeletal muscle and characterized from the viewpoint of the thermostability-structure relationship. Differential scanning calorimetry (DSC) measurement showed that the thermostability of bullet tuna Mb was the lowest among all the scombridae fish Mbs so far examined. The highest value (72.8 degrees C) of melting temperature (Tm) was obtained at pH 6.52. alpha-Helical content at 10 degrees C was 34.5%, clearly lower than that of horse Mb (55.3%). The amino acid sequence was then deduced by cloning cDNA which encodes bullet tuna Mb. Bullet tuna Mb consisted of 147 amino acids, and the sequence identity was very close to that of skipjack (Katsuwonus pelamis) Mb (91.8%). A few amino acid substitutions, which could be involved in stability difference of Mb, were recognized. By mass spectrometry of lysyl endoproteinase digest of Mb, the N-terminus was found to be acetylated like that of other fish Mbs.     

Influence of truck-transportation on the function of bronchoalveolar lavage fluid cells in cattle

The study sought to evaluate whether truck-transportation had an impact on the respiratory immune system of cattle. Six castrated 6-10-month-old Holstein calves were shipped approximately 100 km by road for 4 h. Plasma and bronchoalveolar lavage (BAL) fluid samples, collected immediately before transportation, at 4 h (soon after transportation), and on days 3 and 7 after transportation, were examined. A marked elevation of plasma cortisol concentration was observed at 4 h, but this level was unchanged in controls. The chemiluminescence (CL) response of phagocytes in BAL fluid cells, composed mainly of alveolar macrophage, decreased significantly after transportation (P<0.05). Transportation increased the CD3+ T cell population significantly (P<0.05), and a significant increase (P<0.05) in the ratio of CD4+ to CD8+ cells in BAL fluid was evident. We conclude that short-term road transportation alters pulmonary cells and their function, which may engender bovine respiratory disorders.     

Nucleocapsid-like structures of Ebola virus reconstructed using electron tomography

Electron tomography (ET) is a new technique for high resolution, three-dimensional (3D) reconstruction of pleiomorphic macromolecular complexes, such as virus components. By employing this technique, we resolved the 3D structure of Ebola virus nucleocapsid-like (NC-like) structures in the cytoplasm of cells expressing NP, VP24, and VP35: the minimum components required to form these NC-like structures. Reconstruction of these tubular NC-like structures of Ebola virus showed them to be composed of left-handed helices spaced at short intervals, which is structurally consistent with other non-segmented negative-strand RNA viruses.     

Antigenic differences between H5N1 human influenza viruses isolated in 1997 and 2003

To assess whether the antigenic properties of H5 hemagglutinin (HA) change over time due to antigenic drift, we produced a panel of monoclonal antibodies (mAbs) against the HA of the index H5N1 human influenza A virus, A/Hong Kong/156/97. By immunizing mice with a plasmid expressing this HA and boosting the initial immunization with cell lysates transfected with the plasmid, a total of six hybridomas producing HA-specific mAbs were established: four to the HA1 subunit with hemadsorption-inhibiting activity and two to the HA2 subunit. None of the mAbs to HA1 could bind to the HA of a recent human isolate, A/Hong Kong/213/2003, indicating that there are substantial antigenic differences between the H5N1 human influenza virus isolated in 1997 and that isolated in 2003.