桔小实蝇国内研究概况

本综述了桔小实蝇的研究概况,包括桔小实蝇的分布、寄主、为害情况、种类、生物学、生态学、生理生化、经济重要性评价、综合防治等方面。     

Cloned zebrafish by nuclear transfer from long-term-cultured cells

Although mammals have been cloned from genetically manipulated cultured cells, a comparable achievement has not been realized in lower vertebrates. Here we report that fertile transgenic zebrafish can be obtained by nuclear transfer using embryonic fibroblast cells from long-term cultures. The donor nuclei, modified by retroviral insertions expressing green fluorescent protein (GFP), were transplanted into manually enucleated eggs. Overall, a 2% success rate was achieved, resulting in 11 adult transgenic zebrafish expressing GFP. These nuclear transplants produced fertile, diploid offspring, and their F1/F2 progeny continued to express GFP in a pattern identical to that of the founder fish. This finding demonstrates that slowly dividing nuclei from cultured cells can be reprogrammed to support rapid embryonic development and sets up a foundation for targeted genetic manipulation in zebrafish.     

分子标记分析二十三种香型水稻十个食味品质相关基因的基因型

选取23种香型水稻品种为供试材料,利用分子标记检测方法,进行了10个与稻米食味品质相关基因：耽、SSII-3、SBE3、AGPiso、SSIII-2、AGPlar、P比、SSI、ISA、SSIV-2的基因型分析。结果发现,含有最好食味品质基因型的水稻是“2845”;其次是“松香早粳”、“苏沪香粳”、“B1”、“武运2645”、“通运粳”、“银香28”、“香粳49②”、“99983”、“W香99075”、“07-08”、“云粳优15”、“29185”、“南海318”：另外9种香稻,“大华香粳”、“武香14”、“香粳”、“Della光身稻”、“大粒香”、“泰国香稻”、“C香517”、“香稻1号”、“中香1号”都分别含有一些可能会影响稻米食味品质的基因型。开展本研究不仅能够使人们对这些香稻食味品质基因型有一个全面的认识,还可为今后利用分子标记辅助培育优良食味品质香稻新品种和亲本的选择提供重要的基因型信息。     

铅对鲫鱼碱性磷酸酶和酸性磷酸酶活性的影响

在实验条件下,将鲫鱼置于1、10、40 mg/L的Pb2 溶液中静态染毒,分别在24 h、48 h、96 h、144 h测定鳃、肝、胰、肾、脑组织的碱性磷酸酶(AKP)和酸性磷酸酶(ACP)活性.结果 表明,鲫鱼鳃、肝、胰、肾、脑组织中碱性磷酸酶和酸性磷酸酶的活性随着铅浓度的升高和染毒时间的延长均呈下降趋势,其中以肾脏和脑下降最明显.     

促细胞黏附生长的自组装肽水凝胶

随着细胞与组织工程的迅猛发展,能够促进细胞黏附、生长和分化的生物材料基质支架的研究日益重要。具有生物相容性且含水量超过99％的自组装肽水凝胶因其很好地符合理想的生物材料基质支架标准而备受重视。这类自我互补的两亲寡肽含50％的带电残基,并且以交替的离子亲水性和不带电的氨基酸残基周期性重复为特征;在其寡肽的氨基末端可用直接固相合成法修饰几个短序列生物活性模体进行功能化,用以促进不同细胞的黏附生长和靶向定位。现对自组装肽水凝胶的结构特征、自组装机制、对细胞黏附生长的影响以及未来自组装肽生物材料设计的目标进行综述．     

Inhibition of Endoplasmic Reticulum Stress-induced Apoptosis by Silkworm Storage Protein 1

The endoplasmic reticulum (ER) plays essential roles indispensable for cellular activity and survival, including functions such as protein synthesis, secretory and membrane protein folding, and Ca²⁺ release in cells. The ER is sensitive to stresses that can lead to the aggregation and accumulation of misfolded proteins, which eventually triggers cellular dysfunction; severe or prolonged ER stress eventually induces apoptosis. ER stress-induced apoptosis causes several devastating diseases such as atherosclerosis, neurodegenerative diseases, and diabetes. In addition, the production of biopharmaceuticals such as monoclonal antibodies requires the maintenance of normal ER functions to achieve and maintain the production of high-quality products in good quantities. Therefore, it is necessary to develop methods to efficiently relieve ER stress and protect cells from ER stress-induced apoptosis. The silkworm storage protein 1 (SP1) has anti-apoptotic activities that inhibit the intrinsic mitochondrial apoptotic pathway. However, the role of SP1 in controlling ER stress and ER stress-induced apoptosis has not been investigated. In this paper, we demonstrate that SP1 can inhibit apoptosis induced by a well-known ER stress inducer, thapsigargin, by alleviating the decrease in cell viability and mitochondrial membrane potential. Interestingly, SP1 significantly blocked increases in CHOP and GRP78 expression as well as ER Ca2+ leakage into the cytosol following ER stress induction. This indicates that SP1 protects cells from ER stressinduced apoptosis by functioning as an upstream inhibitor of apoptosis. Therefore, studying SP1 function can offer new insights into protecting cells against ER stress-induced apoptosis for future applications in the biopharmaceutical and medicine industries.     

粘质沙雷氏菌H3010发酵型D-乳酸脱氢酶基因的克隆表达、纯化及酶学性质研究

通过PCR技术从粘质沙雷氏菌H3010基因组DNA中扩增出该D-乳酸脱氢酶基因,连接至pET-28a（＋）表达载体,转入大肠杆菌BL21（DE3）中进行了重组表达,优化了酶纯化的条件,并对其酶学性质进行初步研究。结果表明,获得的该酶编码基因全长993bp,编码330个氨基酸,大小为37kDa。经优化表达及纯化条件后重组酶纯度可达90％。酶学性质研究发现,该重组酶最适反应温度为60℃,最适酶促反应pH为7．5（O．2mol／L磷酸盐缓冲液）,37℃下测得对底物丙酮酸的动力学参数Km=3．39mmol／L,Vmax=6．87mmol／（mg·min）,对辅酶NADH的动力学参数Km=1．43mmol／L,Vmax=1．61mmo]／（mg·min）。为酶法生产D-乳酸及利用代谢工程构建产D-乳酸的基因工程菌打下基础。     

Molecular genetic characterization of H5N1 influenza virus strains isolated from poultry in the Kurgan region in 2005

In the second half of 2005, a large-scale outbreak of influenza in poultry and wild birds was caused by a highly pathogenic H5N1 influenza virus in Russia. The level of pathogenicity is a polygenic trait, and most individual genes contribute to the influenza A virus pathogenicity in birds, animals, and humans. The full-length nucleotide sequences were determined for H5N1 strains isolated in the Kurgan region (Western Siberia). The structure of viral proteins was analyzed using the deduced amino acid sequences. The receptor-binding site of hemagglutinin (HA) in strains A/chicken/Kurgan/05/2005 and A/duck/Kurgan/08/2005 was typical for avian influenza viruses and contained Glu and Gly at positions 226 and 228, respectively. The structure of the basic amino acid cluster located within the HA cleavage site was identical in all isolates: QGERRRKKR. According to the neuraminidase structure, all H5N1 isolates from the Kurgan region were assigned to the Z genotype. Amino acid residues typical for the avian influenza virus were revealed in 30 out of 32 positions of M1, M2, NP, PA, and PB2, determining the host range specificity. One of the strains contained Lys at position 627 of PB2. Isolates from the Kurgan region were shown to have a remantadine-sensitive genotype. Both strains contained Glu at position 92 of NS1, indicating that the virus is interferon-resistant. Phylogenetic analysis related the Kurgan isolates to subclade 2 of clade 2 of highly pathogenic H5N1 influenza viruses.     

Cryoprotective properties and preliminary characterization of exopolysaccharide (P-Arcpo 15) produced by the Arctic bacterium Pseudoalteromonas elyakovii Arcpo 15

Twenty-two bacterial strains that secrete exopolysaccharides (EPS) were isolated from marine samples obtained from the Chukchi Sea in the Arctic Ocean; of these, seven strains were found to be capable of producing cryoprotective EPS. The ArcPo 15 strain was isolated based on its ability to secrete large amounts of EPS, and was identified as Pseudoalteromonas elyakovii based on 16S rDNA analysis. The EPS, P-ArcPo 15, was purified by protease treatment and gel filtration chromatography. The purified EPS (P-ArcPo 15) had a molecular mass of 1.7 × 10⁷ Da, and its infrared spectrum showed absorption bands of hydroxyl and carboxyl groups. The principal sugar components of P-ArcPo 15 were determined to be mannose and galacturonic acid, in the ratio of 3.3:1.0. The cryoprotective properties of P-ArcPo 15 were characterized by an Escherichia coli viability test. In the presence of 0.5% (w/v) EPS, the survival percentage of E. coli cells was as high as 94.19 ± 7.81% over five repeated freeze–thaw cycles. These biochemical characteristics suggest that the EPS P-ArcPo 15 may be useful in the development of cryoprotectants for biotechnological purposes, and we therefore assessed the utility of this novel cryoprotective EPS.     

染色质免疫沉淀技术在研究DNA与蛋白质相互作用中的应用

在后基因组时代,DNA-蛋白质的相互作用是研究基因表达调控的一个重要领域。与其他方法相比,染色质免疫沉淀技术（chromatin immunoprecipitation assay, ChIP）是一种在体内研究DNA-蛋白质相互作用的理想的方法。近年来这种方法与DNA芯片和分子克隆技术相结合,可用于高通量的筛选已知蛋白因子的未知DNA靶点和研究反式作用因子在整个基因组上的分布情况,这将有助于深入理解DNA-蛋白质相互作用的调控网络。总结了染色质免疫沉淀技术的方法,特别介绍了使用这些方法取得的最新进展。