Two novel SNPs of the ABCG2 gene and its associations with milk traits in Chinese Holsteins

The ATP-binding cassette transporter ABCG2 (also known as breast cancer resistance protein, BCRP) belongs to the ATP-binding cassette (ABC) family of transmembrane drug transporters, playing a crucial role in the protection of various cells and tissues against xenotoxins and/or endotoxins. Recently, several studies have proposed it as the potential gene underlying the QTL on bovine chromosome 6. Hence, in this study, the PCR-SSCP method was applied to detect two polymorphisms (A → C and A → G) in the target sequence coding nucleotide-binding domain (NBD) region of ABCG2 and evaluate its associations with milk production traits and mastitis-related traits among Chinese Holsteins. In the analyzed population, the allelic frequencies for the A and B alleles were 0.5990 and 0.4010, respectively and the genotypic frequencies were in Hardy–Weinberg disequilibrium (P < 0.01). Moreover, significant statistical relationships between the polymorphisms of ABCG2 gene and following traits, including milk yields, milk protein percentage and somatic cell scores (SCS), were found (P < 0.05). When compared with AA genotype, BB genotype was associated with higher milk yields during 1st and 2nd lactations, as well as lower milk protein percentage and SCS. Thus, BB genotype is suggested to be a molecular marker for superior milk performance.     

Extracellular hydrolase enzyme production by soil fungi from King George Island, Antarctica

Various microbial groups are well known to produce a range of extracellular enzymes and other secondary metabolites. However, the occurrence and importance of investment in such activities have received relatively limited attention in studies of Antarctic soil microbiota. In order to examine extracellular enzyme production in this chronically low-temperature environment, fungi were isolated from ornithogenic, pristine and human-impacted soils collected from the Fildes Peninsula, King George Island, Antarctica during the austral summer in February 2007. Twenty-eight isolates of psychrophilic and psychrotolerant fungi were obtained and screened at a culture temperature of 4°C for activity of extracellular hydrolase enzymes (amylase, cellulase, protease), using R2A agar plates supplemented with (a) starch for amylase activity, (b) carboxymethyl cellulose and trypan blue for cellulase activity or (c) skim milk for protease activity. Sixteen isolates showed activity for amylase, 23 for cellulase and 21 for protease. One isolate showed significant activity across all three enzyme types, and a further 10 isolates showed significant activity for at least two of the enzymes. No clear associations were apparent between the fungal taxa isolated and the type of source soil, or in the balance of production of different extracellular enzymes between the different soil habitats sampled. Investment in extracellular enzyme production is clearly an important element of the survival strategy of these fungi in maritime Antarctic soils.     

Improvement of strain discrimination by combination of RAPD with PFGE for the analysis of the swine isolates of Salmonella enterica serovar Choleraesuis

Salmonella enterica serovar Choleraesuis (S. Choleraesuis) can cause salmonellosis in pigs and humans. Currently, the most common method used for the subtyping of this Salmonella serovar is pulsed field gel electrophoresis (PFGE) using XbaI as a DNA digestion enzyme. In this study, we compared and combined PFGE with the randomly amplified polymorphic DNA method, for the typing of 95 S. Choloraesuis strains isolated from diseased pigs. Using PFGE with XbaI, with AvrII, and with SpeI digested DNA, 29, 74, and 40 patterns, respectively, were obtained. Also, 53, 15, and 35 strains, respectively, belong to the major patterns X1, A1, and S1. When these three digestion patterns were combined, 83 PFGE pattern combinations were obtained. On the other hand, using RAPD with selected primer alone generated 76 patterns, and 11 strains which fell within a single X1A1S1 PFGE combination pattern were discriminated into 10 patterns. Thus, for S. Choloraesuis, PFGE with AvrII allowed higher discrimination than PFGE with XbaI, and some of the PFGE groupings obtained by combining the XbaI, AvrII and SpeI digestion patterns were further subdivided by the RAPD method.     

Keggin polyoxometalate-templated chair-like heptanuclear silver complex

Two isostructural Keggin-templated compounds containing a chair-like heptanuclear silver complex, [{Ag₇(Hbtz)₂(btz)₄}{PM₁₂O₄₀}]·H₂O (M = W, 1; Mo, 2) (Hbtz = benzotriazolate), have been hydrothermally synthesized and characterized by routine methods and single crystal X-ray diffraction. In the compounds 1 and 2, the Hbtz ligands present two types of coordination modes. A pentameric silver chain with two kinds of Ag?Ag weak interactions exists in the heptanuclear silver complex. The heptanuclear silver cations connect the polyoxoanions PM₁₂O₄₀³⁻ to a two-dimensional layer, and the adjacent layers are fused together by the pseudo wave-like chains, H-bonds and Ag^I–π interactions, constructing a three-dimensional net. Furthermore, electrochemical properties have been studied for compounds 1 and 2 and the two compounds display excellent electrocatalytic activities to the reduction of nitrite.     

Pro-inflammatory effect of fibrinogen and FDP on vascular smooth muscle cells by IL-6, TNF-α and iNOS

AimsAtherosclerosis is a chronic inflammatory response of the arterial wall to multiple endothelial injuries. As one of the inflammatory markers, fibrinogen has been implicated in pathogenesis of atherosclerosis. But, it is not completely understood whether atherogenesis of fibrinogen is related to its pro-inflammatory effect on vascular smooth muscle cells (VSMCs). The purpose of the present study was to observe effects of fibrinogen and fibrin degradation products (FDP) on interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and inducible nitric oxide synthase (iNOS) generation in rat VSMCs.Main methodsRat VSMCs were cultured, and fibrinogen and FDP were used as stimulants for IL-6, TNF-α, and iNOS. IL-6 and TNF-α level in the supernatant were measured by ELISA, mRNA expression of IL-6, TNF-α, and iNOS were assayed with RT-PCR, and protein expression of iNOS was detected with western blot and immunocytochemistry.Key findingsFibrinogen and FDP both significantly stimulated mRNA and protein expressions of IL-6, TNF-α and iNOS in VSMCs in time- and concentration-dependent ways. The pro-inflammatory potency of FDP is higher than fibrinogen, which seems to mean that smaller fragments of the protein have greater pro-inflammatory activity. Fibrinogen and FDP promote more protein expressions of IL-6 and TNF-α compared to iNOS, suggesting that fibrinogen and FDP produce a pro-inflammatory effect on VSMCs mainly by IL-6 and TNF-α.SignificanceThese findings are helpful to better understand pro-inflammatory effect of fibrinogen on VSMCs involved in atherogenesis, and imply a therapeutic strategy targeting hyperfibrinogenemia in atherosclerosis.     

Structural characterization of fungus-specific histone deacetylase Hos3 provides insights into developing selective inhibitors with antifungal activity

Fungal infection has long been a chronic and even life-threatening problem for humans. The demand for new antifungal drugs has increased dramatically as fungal infections have continued to increase, yet no new classes of drugs have been approved for nearly 15 years due to either high toxicity or development of drug resistance. Thus, validating new drug targets, especially fungus-specific targets, may facilitate future drug design. Here, we report the crystal structure of yeast Hos3 (ScHos3), a fungus-specific histone deacetylase (HDAC) that plays an important role in the life span of fungi. As acetylation modifications are important to many aspects of fungal infection, the species specificity of Hos3 makes it an ideal target for the development of new antifungal drugs. In this study, we show that ScHos3 forms a functional homodimer in solution, and key residues for dimerization crucial for its deacetylation activity were identified. We used molecular dynamics simulation and structural comparison with mammalian hHDAC6 to determine unique features of the ScHos3 catalytic core. In addition, a small-molecule inhibitor with a preference for ScHos3 was identified through structure-based virtual screening and in vitro enzymatic assays. The structural information and regulatory interferences of ScHos3 reported here provide new insights for the design of selective inhibitors that target fungal HDAC with high efficiency and low toxicity or that have the potential to overcome the prevailing problem of drug resistance in combination therapy with other drugs.     

Regulation of the lysosome by sphingolipids: Potential role in aging

Sphingolipids are a class of bioactive complex lipids that have been closely associated with aging and aging-related diseases. However, the mechanism through which sphingolipids control aging has long been a mystery. Emerging studies reveal that sphingolipids exert tight control over lysosomal homeostasis and function, as evidenced by sphingolipid-related diseases, including but not limited to lysosomal storage disorders. These diseases are defined by primary lysosomal defects and a few secondary defects such as mitochondrial dysfunction. Intriguingly, recent research indicates that the majority of these defects are also associated with aging, implying that sphingolipid-related diseases and aging may share common mechanisms. We propose that the lysosome is a pivotal hub for sphingolipid-mediated aging regulation. This review discusses the critical roles of sphingolipid metabolism in regulating various lysosomal functions, with an emphasis on how such regulation may contribute to aging and aging-related diseases.     

波对生物组织的作用和机理

波对生物组织的影响越来越受到人们的重视。现选取次声波、超声波和毫米波为代表,概述波对生物组织的作用和相应的机理。提出从波的能量角度出发,结合构成生物组织的物质本身特性,研究和开发波对生物组织更多的有利作用。     

An efficient protocol for genomic DNA extraction from<Emphasis Type="Italic">Citrus</Emphasis> species

We describe a simple and efficient method for genomic DNA extraction from woody fruit crops containing high polysaccharide levels. This method involves a modified CTAB or SDS procedure employing a purification step to remove polysaccharides by using water-saturated ether and 1.25 M NaCl. Precipitation with an equal volume of isopropanol caused a DNA pellet to form. After being washed with 70% ethyl alcohol, the pellet easily dissolved in TE buffer. Using this method, DNA was extracted from samples of more than 1000Citrus spp., including young leaves, old leaves, frosted old leaves, withered old leaves, and callus lines. The average yield of DNA ranged from 50–500 μg/g of sample. DNA was suitable for PCR and RFLP analyses and long-term storage. Recently, the procedure was used to isolate DNA from withered old leaves of more than 20 tropical and subtropical fruit crops.     

New gomphaeschnids and progobiaeshnids from the Yixian Formation in Liaoning Province (China) illustrate the tremendous Upper Mesozoic diversity of the aeshnopteran dragonflies

One new genus and five new species of dragonflies (Odonata) are described and figured from the Yixian Formation of northeastern China, viz. two gomphaeschnids Sinojoria magna nov. sp. and S. cancellosa nov. sp., plus three progobiaeshnids Mongoliaeshna hadrens nov. sp., M. exiguusens nov. sp., and Decoraeshna preciosus nov. gen., nov. sp. These new discoveries confirm the apparently sudden great diversification in China of the clade Aeshnoptera during the Middle-Upper Jurassic, together with the Upper Mesozoic to modern lineages of dragonflies. At the same time, some ‘ancient’ groups of Odonata became extinct.