不同激素及其不同配比对绞股兰愈伤组织诱导的统计学分析

绞股兰的茎段和叶碎片外植体可在合适的激素调节诱导下形成愈伤组织．通过含有不同水平激素的MS培养基对绞股兰愈伤组织诱导试验,经统计学分析,可以找出对绞股兰脱分化形成愈伤组织细胞影响显著的激素及其适宜的激素水平．     

不同育秧方式和插植密度下晚籼稻群体动态结构的研究

不同育秧方式和插植密度下晚籼稻群体动态结构存在差异。旱育秧群体分蘖速度快,分蘖能力强。稀植可促进个体分蘖多发、有效穗数增多,但旱育稀植并无分蘖早发的优势。旱育稀植使主茎基部叶片变短而上部叶片变长,生育后期叶面积消长平稳,地上部干物质积累较多。旱育秧、稀植都使主茎叶总数增多,全生育期延长。     

特种油料植物的种质资源研究

本文对特种油料植物的种质资源研究进行综述,这些植物包括含长链脂肪酸的Crambe,Limnanthes,Lunaria,短链脂肪酸的Cuphea,Lauraceae,羟基脂肪酸的Lesquerella,环氧脂肪酸的Vernonia,Stokesia,以及液体蜡酯的simmondsia等科、属的植物。     

生物制品检定动态管理系统的开发和应用

掌握生物制品的检定动态是质量管理的重要内容,由于检定周期随着制品种类、批数及检定条件的变化而变化,以往靠手工方式查阅繁杂的检定记录,难以随时快速、全面了解当时的检定状况。检定动态管理软件的开发可应用计算机自动跟踪显示检定进度和检定状态,及时反映制品质量和检定条件变化,明显提高了生产和质量管理部门的工作效率。     

提高CO2浓度对两种亚热带树苗生物量及叶片特性的影响

 广东鼎湖山季风常绿阔叶林的主要优势乔木树种荷木和黧蒴幼苗生长于自然光照和人工调节CO2浓度为500±50μl·L-1或空气CO2(350μl·L-1)的气罩中3个月。高CO2浓度下生长的黧蒴和荷木植株总干物质量分别增加26.6％和16.6%,根部增加量最大,地上部分所占的比例降低,根冠比上升,基径增大而株高降低。高CO2浓度下生长的叶片密度及比叶重增加,叶肉细胞间隙体积减少。单位干重的黧蒴叶片可溶性糖含量、全碳、磷、钾含量在高CO2浓度下稍为下降,果糖、葡萄糖、蔗糖、全氮、镁含量及N/C比明显降低。而全钙含量无明显变化。     

Cell cultures derived from early zebrafish embryos differentiate in vitro into neurons and astrocytes

The zebrafish is a polular nonmammalian model for studies of neural development. We have derived cell cultures, initiated from blastula-stage zebrafish embryos, that differentiate in vitro into neurons and astrocytes. Cultures were initiated in basal nutrient medium supplemented with bovine insulin, trout serum, trout embryo extract and fetal bovine serum. After two weeks in culture the cells exhibited extensive neurite outgrowth and possessed elevated levels of acetylcholinesterase enzyme activity. Ultrastructural analysis revealed that the neurites possessed microtubules, synaptic vessicles and areas exhibiting growth cone morphology. The cultures expressed proteins recognized by antibodies to the neuronal and astrocyte-specific markers, neurofilament and glial fibrillary acidic protein (GFAP). Poly-D-lysine substrate stimulated neurite outgrowth in the cultures and inhibited the growth of nonneuronal cells. Medium conditioned by the buffalo rat liver line, BRL, promoted the growth and survival of the cells in culture. Mitotically active cells were identified in cultures that had undergone extensive differentiation. The embryo cell cultures provide an in vitro system for investigations of biochemical parameters influencing zebrafish neuronal cell growth and differentiation.     

Spatial expression dynamics of Men-9 delineate the third floral whorl in male and female flowers of dioecious Silene latifolia

Sex determination in Silene latifolia is controlled by heteromorphic sex chromosomes. Female flowers have five fused carpels and ten arrested stamen primordia. The male-determining Y chromosome overrides female development to suppress carpel formation and promote stamen development. The isolation and characterization of two S. latifoliaM ale en hanced cDNAs, Men-9a and Men-9b, which probably represent different alleles of a novel gene are reported here. Men-9a and Men-9b share 91.8% coding sequence nucleotide identity, yet only 85.4% amino acid identity. The Men-9 cDNAs are related to the previously reported MROS3 cDNA from S. latifolia. However, MROS3 is not present in the S. latifolia population used in these studies and the expression dynamics of Men-9a and Men-9b contrast dramatically with those reported for MROS3. Men-9 cDNAs are expressed primarily in anthers of young male flowers, with highest expression in 1–2 mm buds. Men-9 expression is also observed at a low level in female flowers. In situ hybridization analysis reveals two phases of Men-9 expression. The first phase is during a common stage of early stamen development in male and female flowers prior to stamen arrest in female flowers. The second phase of Men-9 expression is maximal in the epidermis and endothecium of Y chromosome- and Ustilago violacea-induced stamens; expression in male and female flowers extends to the epidermis of the staminal nectaries with strict boundaries at the second and fourth whorls. Men-9 gene expression therefore delineates the boundaries of the third floral whorl in S. latifolia flowers.     

纤蚤属一新种及一新纪录（蚤目：多毛蚤科）

本文报道纤蚤属１９１２ １新种及１新纪录：蔡氏纤蚤和五侧纤蚤似邻近亚种。     

Utilization of chemokine receptors, orphan receptors, and herpesvirus-encoded receptors by diverse human and simian immunodeficiency viruses.

Human immunodeficiency virus type 1 (HIV-1) requires both CD4 and a coreceptor to infect cells. Macrophage-tropic (M-tropic) HIV-1 strains utilize the chemokine receptor CCR5 in conjunction with CD4 to infect cells, while T-cell-tropic (T-tropic) strains generally utilize CXCR4 as a coreceptor. Some viruses can use both CCR5 and CXCR4 for virus entry (i.e., are dual-tropic), while other chemokine receptors can be used by a subset of virus strains. Due to the genetic diversity of HIV-1, HIV-2, and simian immunodeficiency virus (SIV) and the potential for chemokine receptors other than CCR5 or CXCR4 to influence viral pathogenesis, we tested a panel of 28 HIV-1, HIV-2, and SIV envelope (Env) proteins for the ability to utilize chemokine receptors, orphan receptors, and herpesvirus-encoded chemokine receptor homologs by membrane fusion and virus infection assays. While all Env proteins used either CCR5 or CXCR4 or both, several also used CCR3. Use of CCR3 was strongly dependent on its surface expression levels, with a larger number of viral Env proteins being able to utilize this coreceptor at the higher levels of surface expression. ChemR1, an orphan receptor recently shown to bind the CC chemokine I309 (and therefore renamed CCR8), was expressed in monocyte and lymphocyte cell populations and functioned as a coreceptor for diverse HIV-1, HIV-2, and SIV Env proteins. Use of ChemR1/CCR8 by SIV strains was dependent in part on V3 loop sequences. The orphan receptor V28 supported Env-mediated cell-cell fusion by four T- or dual-tropic HIV-1 and HIV-2 strains. Three additional orphan receptors failed to function for any of the 28 Env proteins tested. Likewise, five of six seven-transmembrane-domain receptors encoded by herpesviruses did not support Env-mediated membrane fusion. However, the chemokine receptor US28, encoded by cytomegalovirus, did support inefficient infection by two HIV-1 strains. These findings indicate that additional chemokine receptors can function as HIV and SIV coreceptors and that surface expression levels can strongly influence coreceptor use.     

Hepatitis C virus envelope proteins bind lactoferrin.

Hepatitis C virus (HCV) has two envelope proteins, E1 and E2, which form a heterooligomer. During dissection of interacting regions of HCV E1 and E2, we found the presence of an interfering compound or compounds in skim milk. Here we report that human as well as bovine lactoferrin, a multifunctional immunomodulator, binds two HCV envelope proteins. As determined by far-Western blotting, the bacterially expressed E1 and E2 could bind lactoferrin in human milk directly separated or immunopurified and separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The bindings of lactoferrin and HCV envelope proteins in vitro were confirmed by another method, the pull-down assay, with immunoprecipitated lactoferrin-bound protein A resin. By the same assay, mammal-expressed recombinant E1 and E2 were also demonstrated to bind human lactoferrin efficiently in vitro. Direct interaction between E2 and lactoferrin was proved in vivo, since anti-human lactoferrin antibody efficiently coimmunoprecipitated with secreted and intracellular forms of the E2 protein, but not glutathione S-transferase (GST), from lysates of HepG2 cells transiently cotransfected with the expression plasmids of human lactoferrin and gE2t-GST (the N-terminal two-thirds of E2 fused to GST) or GST. The N-terminal loop of lactoferrin, the region important for the antibacterial activity, has only a little role in the binding ability to HCV E2 but affected the secretion or stability of lactoferrin. Taken together, these results indicate the specific interaction between lactoferrin and HCV envelope proteins in vivo and in vitro.