Combined effect of apigenin and ferulic acid on frozen‐thawed boar sperm quality

The main aim of the present study was to evaluate the cryoprotective effect of apigenin (AP) and ferulic acid (FA) on boar sperm during cryopreservation. AP and FA were both demonstrated to be high‐efficiency antioxidants and had not previously been used to protect sperm from cryodamage. As boar sperm is sensitive to oxidative stress, suitable antioxidants are still needed for improving frozen‐thawed sperm quality. With this purpose, semen samples coming from five boars were used in this study. Ejaculates of five boars were mixed and split into 16 aliquots, in which different doses of AP and FA were added separately or together. The motility, the plasma membrane integrity, the mitochondrial activity, the acrosomal integrity, the antioxidase activities and the malondialdehyde concentration of the frozen‐thawed boar sperm were assessed. The results suggested that both AP and FA significantly improved the frozen‐thawed boar sperm quality in all these aspects when they were added to the freezing extender separately, while the highest improvement was recorded when the extender was supplemented with 0.1 mmol/L AP plus 0.15 mmol/L FA. These findings demonstrated that supplementation of freezing extender with both AP and FA had a combined, beneficial effect on frozen‐thawed boar sperm.     

DREB1A regulon expression in rd29A:DREB1A transgenic chrysanthemum under low temperature or dehydration stress

Summary

Previously we reported that expression of the Arabidopsis DREB1A gene in chrysanthemum conferred increased tolerance to low-temperature and dehydration stresses, and that transgenic plants in which the DREB1A gene was driven by the abiotic stress-inducible promoter, rd29A, were more tolerant than those plants in which the DREB1A gene was driven by the 35S Cauliflower Mosaic Virus (CaMV) promoter. To understand the molecular basis for this improved tolerance, we isolated 74 DREB1A regulon genes using suppression subtractive hybridisation, then compared their expression patterns in rd29A:DREB1A transgenic plants (rd29A plants) and in 35S:DREB1A transgenic plants (35S plants) under different stress conditions. Our results showed that the increased tolerance to low temperatures and dehydration in rd29A plants was attributed to increased levels of expression of different members of the DREB1A regulon. Levels of expression of 69% or 91% for members of the DREB1A regulon that showed upregulation in rd29A plants were highly correlated with the level of expression of DREB1A in response to low temperature or to dehydration, respectively. These results support the hypothesis that the increased tolerance of rd29A plants to abiotic stresses resulted from elevated expression of the DREB1A regulon.     

Partial purification and characterization of eosinophil chemotactic factors from soluble extract of Fasciola species

Eosinophil chemotactic factor (ECF) was partially purified from common liver flukes (Japanese strain of Fasciola sp) by a combination of anion-exchange chromatography on DE52 and gel filtration on Sephacryl S-200. The molecular weight of ECF was estimated to be approximately 27,000 by high-pressure liquid chromatography. The ECF was heat labile (56 and 100 C for 30 minutes) and was not bound with lentil-lectin Sepharose. The results of isoelectric focusing showed that ECF comprises at least 2 components; one was a major ECF with an isoelectric point of 3.1, and the other, a minor ECF with an isoelectric point of 3.8 to 4.5. These results indicate that ECF of common liver flukes are acidic proteins.     

Two gustatory systems: facial and vagal gustatory nuclei have different brainstem connections

The gustatory sense in catfish consists of two dissociable components, a facial nerve system used for food selection and a vagal nerve system involved in swallowing. Neural tracing experiments demonstrate that the primary sensory nucleus for the facial gustatory system is connected to the reticular formation and trigeminal nuclei. In contrast, the primary sensory nucleus for the vagal gustatory system is connected to the motoneurons that mediate swallowing. These results provide anatomical evidence for parallel gustatory systems within the vertebrate central nervous system.     

Mineralization of organic sulfur and its importance as a reservoir of plant-available sulfur in upland soils of north China

 An open incubation technique was used to measure S mineralization in a range of upland soils of north China. Six mineralization patterns were examined, and a soil S-exhaustion experiment with ryegrass (Lolium multiflorum L.) was conducted to investigate the availability of various organic S pools to plants. For all of the 12 soils tested, the release of S as SO₄ ^2– was curvilinear with time, and during a 28-week incubation at 30  °C the amount of S mineralized ranged from 14.0 mg S kg^–1 soil to 37.4 mg S kg^–1 soil. A first-order model and Gompertz model appeared to best describe S mineralization. Examination of the soils after incubation revealed the bulk of the mineralized S was mainly derived from the C-bonded S pool, while the majority of mineralized S under soil S exhaustion by ryegrass was derived from the HI-reducible S pool. Received: 9 July 1998     

Study of oat globulin conformation by Fourier transform infrared spectroscopy.

The conformation of oat globulin dispersions (10% in D2O) under the influence of pH, chaotropic salts, protein structure perturbants, and heating conditions was studied by Fourier transform infrared (FTIR) spectroscopy. The FTIR spectrum of oat globulin showed major bands from 1670 to 1634 cm(-1), corresponding to the four major types of secondary structures, that is, beta-turns, beta-sheets, alpha-helices, and random coils. At extreme acidic and alkaline pH conditions, there were changes in intensity in the bands attributed to beta-sheet structures (1626, 1634, and 1682 cm(-1)), and shifts of the bands to higher or lower wavenumbers, indicating changes in conformation. In the presence of some chaotropic salts, the 1626 and 1634 cm(-1) bands were shifted upward, with a marked decrease in the intensity of the 1634 cm(-1) peak. The addition of several protein structure perturbants led to a slight shift in the alpha-helix/random coil bands and a marked reduction in the beta-sheet peaks, suggesting protein unfolding. Heating under aggregating conditions led to slight shifts in all of the major bands and progressive changes in the intensity of the alpha-helix, beta-sheet, and beta-turn peaks, suggesting protein denaturation. This was accompanied by marked increases in intensity of the two intermolecular beta-sheet bands (1682 and 1624-1626 cm(-1)) associated with the formation of aggregated strands. The IR spectra of soluble and insoluble aggregates showed a redistribution of native and extensively denatured proteins in the two fractions.     

Rhodophyta Seaweed Species as Bioindicators for Monitoring Toxic Element Pollutants in the Marine Ecosystem of Ghana

Six seaweed species of the Rhodophyta family were sampled for atwo-year period from June 1996 to August 1998 along the Atlanticcoast of Ghana (part of the Atlantic Ocean). The species wereanalysed to determine the levels of eleven chemicalelements namely: Al, As, Br, Cd, Fe, La, Mn, Ni, Hg, V and Zn byInstrumental Neutron Activation Analysis (INAA). Al, Br, Ni, andZn were measured in all the seaweed species studied. The elementAl generally showed the highest concentrations in most of thespecies analysed while Hg levels were the lowest. Precision andaccuracy of the method have been evaluated and the detectionlimits also calculated. The results showed high variability inand between species, among sampling sites and times ofcollection. The high values of metal concentrations in themacroalgae suggest that these marine organisms can be used asbiological indicators for studing marine pollution.     

6个典型四川小麦品种不同生育期抗条锈性研究

试验于2011～2012年通过大田高感品种自然诱发对近年四川小麦生产上具有较大影响力的6个代表性小麦品种进行了不同生育期抗条锈性研究.经方差分析结果表明,6个小麦品种在不同生育期对条锈菌的反应型有极显著性差异(p＜0.001),病情指数有显著差异(0.01＜p＜0.05).多重比较结果显示,6个品种反应型在不同生育期出现先升后降的趋势,而川育23反应型逐渐降低,川农26反应型逐渐升高;病情指数研究表明,川农26病情指数逐渐增高,川育23病情指数逐渐降低,其他品种病情指数变化不明显.结合品种的农艺性状的比较,绵杂168、川麦42、西科麦4号、内麦9号抗条锈性优良,川农26抗条锈性差,应逐渐淘汰,川育23可能携带有高温抗锈基因将有待于进一步研究.     

玉米苗期抗旱性杂种优势表现研究

以43个玉米杂交组合及其相应亲本为材料,利用20%PEG-6000溶液在苗期模拟干旱胁迫,研究玉米苗期抗旱性的杂种优势表现,并探讨与亲本间的相关性。结果表明,12个组合存在正向超亲优势,18个组合具有正向中亲优势;以中单808作为对照,13个组合表现为正向对照优势。玉米杂交组合苗期抗旱性和对照优势与母本、父本、高值亲本、低值亲本及亲本均值间的相关性一致,均未到达显著水平,表明玉米杂交组合苗期抗旱性和对照优势与亲本间无明显的相关性,在育种实践中,不能根据亲本抗旱性来预测杂交种的抗旱性。     

The impact of daily Duddingtonia flagrans application to lactating ewes on gastrointestinal nematodes infections in their lambs in the Netherlands

Two experiments were performed in 2002 and 2003 to evaluate the effect of biological control of gastrointestinal nematodes in sheep through the daily feeding of 500,000 chlamydospores of Duddingtonia flagrans/kg bodyweight to lactating ewes during the first 9 weeks with their young lambs on pasture. In both experiments four groups of eight ewes and their April-borne lambs were used. They were turned out on four separate plots (plots A) at the beginning of May, moved to similar separate plots after 3 (plots B) and 6 weeks (plots C), respectively, and weaning occurred after 9 weeks. In both experiments, two groups were fed spores daily while the two other groups served as controls. The effect of D. flagrans application was evaluated through faecal egg counts of ewes and lambs, the yield of faecal cultures in ewes, pasture larval counts and worm counts of lambs and tracer lambs. The results demonstrated no effect of D. flagrans application during the first 5 (2002) or 4 (2003) weeks. Subsequently, fungus application strongly reduced the yield in faecal cultures of the ewes. This was, however, not reflected in the pasture larval counts, but lower worm burdens were observed in tracer lambs of 'treated' plots C in 2002 than on those of 'control' plots. In 2003 worm burdens in 'treated' lambs returned to plots B were lower than those of 'control' lambs and a tendency for the same was observed for plots C. However, in all groups, lambs and tracer lambs developed severe haemonchosis.