三疣梭子蟹含硒谷胱甘肽过氧化物酶基因克隆及其表达分析

为探究三疣梭子蟹的免疫机制以及谷胱甘肽过氧化物酶(GPx)在甲壳动物响应寄生虫感染免疫过程中的作用,本研究采用RACE方法从三疣梭子蟹中克隆获得硒半胱氨酸-谷胱甘肽过氧化物酶基因的全长cDNA序列,其cDNA序列全长为696bp,5′-UTR长度为102bp,3′-UTR长度为87bp,开放阅读框长度为507bp,编码168个氨基酸,其中含有一个典型的由蛋白石终止密码子(220TGA222)编码的硒半胱氨酸(40U)。预测了该基因编码的氨基酸序列及其中的保守结构域,包括GPx家族签名序列(64LAFPCNQF71)、活性位点序列(152WNFEKF157)以及与酶催化活性相关的氨基酸位点包括谷氨酰胺(74Q)、精氨酸(90R和168R)和色氨酸(142W)。相似性比对和系统发育分析结果表明,三疣梭子蟹硒半胱氨酸-谷胱甘肽过氧化物酶(SeGPx)与甲壳动物中的SeGPxs相似性较高,其中与拟穴青蟹SeGPx相似性最高,并与其在系统发育树中聚为一支。经血卵涡鞭虫侵染后(0—192h),SeGPx基因在三疣梭子蟹的血细胞、肝胰腺和鳃组织中的转录水平均发生显著性升高。该结果表明,SeGPx在三疣梭子蟹应对血卵涡鞭虫的免疫反应中发挥重要作用,可通过调控甲壳宿主体内被病原扰乱的氧化还原状态进而起到宿主组织保护作用。     

Expression,purification, and subcellular localization of phospholipase C in Dunaliella salina

Plants possess effective mechanisms to respond quickly to the external environment. Rapid activation of phosphatidylinositol-specific phospholipase C (PLC) enzymes occurs after a stimulus. The PLC in Dunaliella salina plays important roles in growth and stress responses. However, the molecular basis of PLC action in D. salina remains little understood. To gain insight into the potential biological functions of this enzyme, we cloned a phospholipase C gene from D. salina in a previous study, named DsPLC (GenBank No. KF573428). Here, we present the prokaryotic expression, purification, and characterization of the DsPLC gene. The entire coding region of DsPLC was inserted into an expression vector pET32a, and the DsPLC gene was successfully expressed in Escherichia coli. The DsPLC protein was purified and identified using a polyclonal antibody and western blotting. Expressing DsPLC fused with a green fluorescent protein (GFP) in onion showed that DsPLC-GFP was localized to the intracellular membrane. Quantitative real-time PCR analysis revealed that the relative expression of the DsPLC gene was induced significantly by 3.0-mol/L NaCl at 4 h. Our results support the importance of PLC enzymes in plant defense signaling. This study provides a basis for further functional studies of the DsPLC gene and for additional analysis of the potential roles of PLC enzymes in response to abiotic stress.     

传统村落空间布局的图式语言研究 ——以张谷英村为例

以中国传统村落张谷英村为研究对象,从景观基因理论视角对张谷英村进行空间要素识别和空间解构,构建张谷英村空间布局的图式语言体系,通过对空间布局的秩序、语法和意义的研究,探索了空间布局的嵌套结构、过程机理及逻辑脉络。研究表明： 张谷英村空间布局可划分为居住空间、连接空间、附属空间和复合空间,归纳提取 “字”“词”和“词组”共86种图式语汇,构建了空间布局的图式原型数据库。 建立张谷英村空间布局图式语言体系,该体系具备完整的图式语言逻辑,其发展模式和空间秩序始终遵循着宗法礼制思想和传统伦理道德。 张谷英村空间布局图式语言具有完整而稳定的设计句法和语法,图式语汇丰富,句法组合类型多样,语法结构则相对单一,形成了局部复杂多变,整体相对单一的村落空间布局。 村落空间结构及元素细节在发展中不断进行修正和改变,空间布局表现出极高的整理性、顺应性和一致性。 村落空间构建元素和设计理念地方特色鲜明,图式语言的语汇及空间法则具有强烈的地域性特征。     

栉孔扇贝NDPK 基因的BAC-FISH 定位研究

栉孔扇贝(Chlamys farreri)是我国北部沿海一个非常重要的养殖种类。核苷二磷酸激酶(NDPK)是一类广泛存在、高度保守,在细胞能量和信息传递中具有重要作用的酶。作者利用BAC-FISH技术将两个包含栉孔扇贝NDPK基因的BAC克隆定位到染色体同一位置上,该结果验证了物理图谱相关contig组装的可靠性,同时NDPK基因的染色体定位将对深入研究该基因的结构、功能以及应用于生产实践提供理论支撑。本研究结果将对栉孔扇贝染色体的深入研究以及染色体鉴别、图谱整合等工作提供重要参考。     

Wild Barley, Hordeum spontaneum, a Genetic Resource for Crop Improvement in Cold and Arid Regions

Food security in cold and arid regions in the world is threatened by stressful and unpredictable environments.The sus-tainable and economically viable solution for increasing stability of food productivity in cold and arid regions is genetic improvement of crops towards high resistance to abiotic stresses,mainly cold and drought resistance.It is often empha-sized that crop genetic improvement lies in exploiting the gene pools of the wild relatives of the crop plant.Wild barley,H.spontaneum,the progenitor of cultivated barley,is a selfing annual grass of predominantly Mediterranean and Irano-Turanian distribution that penetrates into desert environments where it maintains stable populations.Wild barley is also found in cold regions,such as in Tibet.The adaptation of wild barley to the arid region in Israel and Jordan,and the cold region in Tibet has accumulated rich genetic diversities for drought,salt,and cold resistances in wild barley,which is the genetic resource for barley and other crop improvement in arid and cold regions.These genetic diversities are revealed by allozymes,DNA-based molecular markers,and morphological and physiological traits of wild barley plants.Quantita-tive trait loci(QTLs) related to drought resistance were identified in wild barley via the QTL mapping approach.Drought resistance genes such as dehydrins,hsdr4,and eibi1 were identified in wild barley based on the candidate gene approach,gene differential expression approach,and molecular genetic approach,respectively.Genetics and genomics of wild bar-ley cold resistance have not been exploited yet,remaining a huge treasure for future crop improvement of cold resistance.Advanced backcross QTL analysis,the introgression libraries based on wild barley as donors,a QTL approach based on wide crosses using wild barley,and positional cloning of natural QTLs will play prevailing roles to help us understand the molecular control of cold and drought tolerance.Integration of QTL information into a breeding pipeline aimed at im-proving tolerance t     

尾索动物线粒体基因组特征比较及分子系统发育

为全面揭示尾索动物线粒体基因组的基本特征,作者系统分析了12种尾索动物的线粒体基因组全序列,尾索动物线粒体基因组所有的基因均在同一链上编码,这与脊椎动物、头索动物线粒体基因组的基因分布特征显著不同.与后生动物线粒体基因组标准的基因组成相比,尾索动物线粒体基因组存在转运 RNA基因的增加以及部分物种 atp8基因的缺失.在尾索动物线粒体基因组中发生了大规模的基因重排,即使在同属物种的线粒体基因组中,也存在主编码基因的基因重排及基因缺失.尾索动物线粒体基因组蛋白质编码基因的起始密码子、终止密码子及氨基酸长度存在明显差异.2个玻璃海鞘(Ciona intestinalis 和 C. savignyi)线粒体基因组12个蛋白质编码基因的 Ka/Ks 比值都低于1(0.0927~0.6752),显示出一定的负选择.在所有的主编码基因中, nad5基因和nad4基因的变异位点最多,可以作为备选的分子标记,用于分析尾索动物不同物种之间的生物多样性.基于线粒体基因组的系统发育分析,支持尾索动物在科级的亲缘关系为:(((柄海鞘科 Pyuridae+芋海鞘科 Styelidae)+(((三段海鞘科Polyclinidae+星骨海鞘科Didemnidae)+簇海鞘科Clavelinidae)+玻璃海鞘科Cionidae))+长纹海鞘科Ascidiidae)+海樽科Doliolidae.     

沉积物中氨氧化细菌amoA基因荧光定量PCR检测方法的改进

聚合酶链式反应(Polymerase chain reaction,PCR)较容易受到某些抑制成分的影响,尤其是在对复杂环境样品进行的荧光定量PCR反应中,定量结果的准确性更易受到影响。为减轻这种抑制作用,以采自长江口邻近海域沉积物的DNA为研究对象,采用稀释模板法和添加BSA法对荧光定量PCR反应进行了优化。结果表明2种方法都有减轻抑制的作用,但若考虑方法的准确性和检测的便捷性,则以添加BSA的方法更为优越,最适添加浓度为0.1～0.5μg/μL。这一检测方法的改进,为研究沉积物中微生物在硝化过程中的重要作用提供了可靠的技术途径。