猕猴桃成熟果实中脂氧合酶基因的克隆

采用ＰＣＲ扩增方法,从成熟猕猴桃果实组织中克隆到一个８２４ｂｐ的脂氧合酶（ＬＯＸ）基因片段（ｐＫＬＣ１）,该片段含有２７５个氨基酸组成的开放阅读框架,它与拟南芥菜、黄瓜、豌豆、土豆、水稻、大豆、烟草和番茄的核苷酸同源性为５９．０％～７４．６％,氨基酸同源性为６３．１％～７６．３％。Ｓｏｕｔｈｅｒｎ杂交表明,ｐＫＬＣ１片段为一低拷贝数基因家族所编码。     

Decomposition of (1–3,1–4)-β-Glucan and Expression of the (1–3,1–4) -β-Glucanase Gene in Rice Stems during Ripening

Abstract

To elucidate the possible participation of hemicellulose decomposition in lodging resistance, we studied the change of hemicellulose and cellulose content in the stems of rice during the ripening stage by methylation analysis and the expression of related genes by Northern blotting. In the rice stem in ripening stage, content of (1-3,1-4)-β-glucan, a component of hemicellulose, decreased markedly although the content of arabinoxylan, a major component of hemicellulose, and cellulose showed little change during the same growth period. On the other hand, expression of the Gns 1 gene, which may encode (1-3,1-4) -β-glucanase that catalyzes the degradation of (1-3,14) -β-glucan, increased sharply in the stem. The mechanism of decomposition of (1-3,1-4) -β-glucan in rice stem and the possible association with lodging resistance is discussed.     

基因多态性与牛疾病相关性的研究进展

基因多态性是指基因组序列上的变异,它是决定家畜对疾病易感性与抵抗力、疾病临床表现多样性以及不同个体对药物反应性的重要因素.研究基因多态性有利于定位和鉴定致病基因和疾病易感基因,使得从遗传学的角度控制疾病成为可能,从而达到减少家畜疾病防治的成本,改良家畜品种,为人类提供健康的动物产品的目的.笔者主要从抗病育种的角度综述了近年来基因多态性与牛疾病易感性和抗性的相关研究,并结合遗传信息学和表观遗传学,阐述家畜疾病控制的新进展.     

白菜型油菜双显性核不育896AB恢复系基因型的鉴定

以白菜型油菜双显性核不育896AB为材料，采用成对兄妹交和相应可育株自交，验证显性不育基因的遗传;用恢复系与全不育系测交，测交一代与临保系复交，验证显性恢复基因的抑制作用，并区分F2代育性分离为3:1和13:3的遗传类型。经4个年度的研究认为，育性是由一对显性不育基因MSMS和一对显性可育基因RfRf互作控制，且显性可育基     

Gene Expression of Enzymes for Starch and Sucrose Metabolism and Transport in Leaf Sheaths of Rice (Oryza sativa L.) during the Heading Period in Relation to the Sink to Source Transition

Abstract

Leaf sheaths of rice plants are known to temporarily accumulate starch prior to heading, which is subsequently remobilized and transported into the panicle after heading. We investigated the time course for both carbohydrate content and steady state mRNA levels of enzymes related to starch and sucrose metabolism in the rice leaf sheath (Oryza sativa L. cv. Nipponbare). Leaf sheaths from the second leaf below the flag leaf accumulated high levels of starch before heading but they rapidly decreased after heading. In contrast, the flag leaf sheath did not accumulate as much starch. In the second leaf sheath, the mRNA levels of enzymes involved in starch synthesis, ADP glucose pyrophosphorylase (EC 2. 7. 7. 27), soluble starch synthase (EC 2. 4. 1.21) and branching enzyme (EC 2. 4. 1. 18) were high before heading, which coincided with rapid accumulation of starch. The mRNA levels of sucrose synthesis enzymes, cytosolic FBPase (EC 3. 1. 3. 11) and sucrose phosphate synthase (EC 2. 4. 1. 14), and the sucrose transporter (OsSUTI) increased at the time of heading, which was largely coincident with a decrease in the mRNA levels of starch synthesis enzymes. In the flag leaf sheaths, changes in mRNA levels of starch synthesis enzymes were not pronounced, however mRNA levels of sucrose synthesis enzymes and the sucrose transporter showed a clear increase throughout the heading period. The different characteristics observed between the two leaf sheaths will be discussed in relation to the sink to source transition.     

Advances in the ABCB4 gene in cholestatic disorders

The ABCB4 gene, also called MDR3, encodes the MDR3 protein which is localized to the hepatocyte canalicular membrane and is demonstrated to be a phosphatidylcholine translocase. The recent study showed that ABCB4 deficiency was associated with several cholestatic disorders, but the pathogenesis is not clear. This review highlights recent advances in the structure and function of ABCB4 gene, and the relationship between ABCB4 gene and cholestatic diseases.     

光核桃AmSO基因初克隆及生物信息学分析

为了初步探索光核桃（Amygdalus mira）亚硫酸盐氧化酶（Sulfite oxidase，SO）的蛋白结构与功能，以1 a生光核桃叶片cDNA为模板，采用分子克隆技术获得光核桃AmSO基因全长为1 182 bp的开放阅读框（ORF），共编码393个氨基酸，相对分子质量是43.45 ku。生物信息学分析结果显示，AmSO蛋白是一种能在细胞核内发挥生物学作用的稳定碱性亲水蛋白，二级结构由无规则卷曲、α-螺旋和延伸链构成。蛋白结构域的预测及氨基酸序列同源性比对发现，编码氨基酸序列的N端具有氧化钼结构域，常存在于氧化还原酶中，可以与钼辅因子结合；在C端具有钼钴（Mo-co）二聚体结构域，该结构域参与二聚体的结合，并且能够参与硫、氮和碳循环中的氧化还原反应，二者在进化过程中高度保守。系统进化树分析表明AmSO与碧桃PpSO亲缘性最近，进化相对保守。对光核桃AmSO蛋白进行生物信息学预测，有助于进一步系统研究光核桃 AmSO基因在生物学上的功能，为进一步了解其对非生物胁迫的响应机制奠定基础。     

林木遗传工程及木质素的生物合成调节(英文)

林木遗传工程有利于保存林木遗传资源，改善全球气候，减轻自然林的过度采伐和满足人类日益增长的林木产品需求。控制林木真菌、病毒病、虫害和杂草的遗传工程方法正被广泛地研究和应用。尽管转基因林木的历史不长，种类不多，但它有广泛的应用前景。目前，抗除草剂基因、抗虫基因以及和木材质量相关的基因已被分离并应用于林木遗传工程。植物分子生物学和基因组学中的新技术使得高效林木遗传改良成为可能并将促进这些技术的商业化应用。木质素的应用已有一百年的历史，但木质素生物合成的全过程并不完全清楚。有关松树自然突变体和转基因林木的最新研究结果表明，木质素的生物合成是一个可以调节的过程。这些发现对完善木质素的生物合成途径、加深对木质素前体生物合成途径的理解和通过遗传工程改善木材质量有促进作用。本文综述了林木遗传工程在这些领域中取得的一些进展。     

工能基因组学:T-DNA介导的基因诱捕和植物基因鉴定(英文)

拟南芥菜、水稻、蕃茄、土豆、玉米、小麦和大豆的全基因组测序为植物细胞和发育生 物学研究提供了许多有用的信息。基因组学的中心任务是利用这些信息去探索蛋白质的功能 和鉴定与发育有关的重要基因。尽管依赖于毁坏基因和产生可识别的突变表型的经典遗传学 方法仍然是极为成功的基因鉴定方法，借助于报告基因结构，随机插入植物基因组的T-DNA 介导的基因诱捕正发展成为植物细胞和发育生物学研究的极强有力的技术。本文描述了基因 诱捕、启动子诱捕和增强子诱捕在植物生物学中的应用，并且希望这些基因鉴定方法有助于 植物分子生物学家和生物技术工作者的研究。     

Altitudinal and longitudinal variations in Pinus brutia (Ten.) of Crete Island,Greece: some needle,cone and seed traits under natural habitats

Four populations representing the entire natural distribution range of Pinus brutia (Ten.) in Crete (Greece) were sampled to determine: (1) Altitudinal variation within populations of Lassithi, Vorizia, Koustagerako, and Samaria, and; (2) Longitudinal variation among the four populations, based on morphological and anatomical differences in cone, needle and seed characteristics. Samples were collected from 10 trees per altitude, at three altitudes in each population. A total of 12 morphological and anatomical traits from needles, cones and seeds were analyzed to assess the altitudinal and longitudinal variations of the species in the island. The number of teeth per cm showed significant (P<0.01) differences between altitudes in Samaria, Vorizia and Lassithi, while needle length, width and the number of resin canals showed significant differences (P<0.01) between altitudes in Koustagerako. Cone width showed patterns of variation along the altitudinal gradient in Koustagerako, Samaria and Vorizia. Most traits had their highest means at the middle altitudes (650masl) in all the four populations. Overall, no clear altitudinal differentiation was detected, probably due to high rate of gene flow. Longitudinal variability showed a clear pattern of differentiation along the east–west climatic gradient. Needle length, width, sheath length, number of teeth per cm and the number of resin canals were the most useful traits for determining the climatic gradient clines.