Structure and characterization of a murine chromosomal fragment containing the interferon beta gene

In this paper we report on the cloning and characterization of the murine interferon (IFN) beta gene. We have isolated and sequenced a 2.8 kb genomic fragment containing the murine IFN beta gene flanked by 1.2 kb 5' and 1 kb 3' untranslated regions (1 kb = 10(3) base-pairs). The mRNA cap site has been defined. An extensive analysis of the flanking sequence is provided and points out striking features such as: the presence of A + T-rich motifs characteristic of transiently expressed mRNAs, and homologies to repetitive R-type element flanks and to hormone-responsive elements. Comparison of the MuIFN beta 5' flanking region with those from other species reveals similarities in the sequences required for the regulated expression of such inducible genes. Computer analysis of the 130 base-pairs preceding the cap site has revealed TGAAAG motifs and shows that the presence of such elements and their permutants have biological significance, according to statistical calculations. Thus, the comparison between the mouse promoter reported here and the promoters from other species highlights the region containing the hexanucleotide blocks, which is strongly conserved.     

Structure of mouse interferon-beta cDNA clones: sequence rearrangements in a cloned cDNA

A fraction enriched in interferon (IFN) mRNA was prepared from mouse C243-3 induced cells and was used for the construction of a cDNA library. Two plasmids were obtained after screening by differential colony hybridization and IFN mRNA hybridization-selection and translation. The nucleotide sequences of the cDNA inserts revealed that both were partial copies of IFN-beta mRNA. The cDNA 861 corresponds to the entire 3' nontranslated region of the mRNA while the cDNA 2939 consists of rearranged translated regions of IFN mRNA. A mechanism for the rearrangement events during cDNA synthesis is proposed. A chromosomal DNA fragment hybridizing to cDNA 2939 was identified by screening a mouse genomic library.     

蒙古黄芪病程相关蛋白AmPR-10于大肠杆菌不同载体的可溶性表达策略研究

蒙古黄芪病程相关蛋白（Astragalus membranaceus pathogenesis-related protein-10, AmPR-10）具有核酸酶活性,对黄芪生长发育及抗病机制具有重要意义。但从天然黄芪中提取蛋白质的传统方法成本较高,蛋白得率较少。研究首次利用大肠杆菌表达体系对AmPR-10进行可溶性外源表达,构建了3种重组子：①以pET28a为载体构建pET28a-AmPR-10;②以pET30a为载体构建pET30a-AmPR-10;③以pET30a为载体、大肠杆菌分子伴侣skp修饰构建pET30a-skp-AmPR-10。通过SDS-PAGE分析,目的蛋白可溶性表达量比较结果是：pET30a-skp-AmPR-10 > pET30a-AmPR-10 > pET28a-AmPR-10。由蛋白质三级结构模拟分析发现,载体pET-30a上的标签S-tag通过影响AmPR-10局部α螺旋构象而提高目标蛋白的可溶性表达,分子伴侣skp通过提高融合蛋白整体α螺旋比例进一步提升目标蛋白可溶性表达量。研究解决了目前从天然黄芪中提取蛋白操作复杂、提取量小的问题。同时,经测定,目的蛋白具有核酸酶活性,为外源AmPR-10相关活性研究提供了依据。     

Patterns of Expression in the Matrix Proteins Responsible for Nucleation and Growth of Aragonite Crystals in Flat Pearls of Pinctada fucata

The initial growth of the nacreous layer is crucial for comprehending the formation of nacreous aragonite. A flat pearl method in the presence of the inner-shell film was conducted to evaluate the role of matrix proteins in the initial stages of nacre biomineralization in vivo. We examined the crystals deposited on a substrate and the expression patterns of the matrix proteins in the mantle facing the substrate. In this study, the aragonite crystals nucleated on the surface at 5 days in the inner-shell film system. In the film-free system, the calcite crystals nucleated at 5 days, a new organic film covered the calcite, and the aragonite nucleated at 10 days. This meant that the nacre lamellae appeared in the inner-shell film system 5 days earlier than that in the film-free system, timing that was consistent with the maximum level of matrix proteins during the first 20 days. In addition, matrix proteins (Nacrein, MSI60, N19, N16 and Pif80) had similar expression patterns in controlling the sequential morphologies of the nacre growth in the inner-film system, while these proteins in the film-free system also had similar patterns of expression. These results suggest that matrix proteins regulate aragonite nucleation and growth with the inner-shell film in vivo.     

中国片叶蝉属二新种(同翅目:叶蝉科:离脉叶蝉亚科)

片叶蝉属ＴｈａｇｒｉａＭｅｌｉｃｈａｒ是离脉叶蝉亚科Ｃｏｅｌｉｄｉｎａｅ中最大的类群,全世界已知１９０种,主要分布于东洋区、澳洲区和古北区［１］,我国记录有４１种［２～５］”。该属不同于离脉叶蝉亚科其它属的显著特点在于：尾节端背缘有成对突起;阳茎简...     

中国片叶蝉属二新种(同翅目：叶蝉科：离脉叶蝉亚科)

Two new species of the gensu Thagria Melichar (Cicadellidae.Coelidiinae) are described and illustrated from China. The type specimens are deposited in the Department of Plant Protection, Anhui Agricultural University, Hefei, China.     

The RhoGEF DOCK10 is essential for dendritic spine morphogenesis

By regulating actin cytoskeleton dynamics, Rho GTPases and their activators RhoGEFs are implicated in various aspects of neuronal differentiation, including dendritogenesis and synaptogenesis. Purkinje cells (PCs) of the cerebellum, by developing spectacular dendrites covered with spines, represent an attractive model system in which to decipher the molecular signaling underlying these processes. To identify novel regulators of dendritic spine morphogenesis among members of the poorly characterized DOCK family of RhoGEFs, we performed gene expression profiling of fluorescence-activated cell sorting (FACS)-purified murine PCs at various stages of their postnatal differentiation. We found a strong increase in the expression of the Cdc42-specific GEF DOCK10. Depleting DOCK10 in organotypic cerebellar cultures resulted in dramatic dendritic spine defects in PCs. Accordingly, in mouse hippocampal neurons, depletion of DOCK10 or expression of a DOCK10 GEF-dead mutant led to a strong decrease in spine density and size. Conversely, overexpression of DOCK10 led to increased spine formation. We show that DOCK10 function in spinogenesis is mediated mainly by Cdc42 and its downstream effectors N-WASP and PAK3, although DOCK10 is also able to activate Rac1. Our global approach thus identifies an unprecedented function for DOCK10 as a novel regulator of dendritic spine morphogenesis via a Cdc42-mediated pathway.