小麦籽粒淀粉分支酶遗传多样性及对支链淀粉含量的影响

采用非变性聚丙烯酰胺凝胶电泳,对90份小麦品种的淀粉分支酶同工酶(SBE)进行检测,以分析不同基因型对支链淀粉含量的遗传效应.结果表明:(1)SBEⅠ型显现出较为丰富的变异,具有A、B、Dⅰ和Dⅱ4个等位基因位点;SBEⅡ型仅具有SBEⅡa单一等位基因位点.根据SBEⅠ型4个基因位点在不同品种中的分布,可将90个品种分为7种基因型.不同基因型对支链淀粉含量的遗传效应分析表明,含有A位点的基因型(ADⅰDⅱ和ADⅰB)所对应的支链淀粉含量较高,且与由1个基因位点组成的基因型(Dⅰ)和2个基因位点组成的基因型(DⅰB和DⅰDⅱ)的支链淀粉含量差异显著.     

云南稻籼粳亚种间功能性成分含量差异

对111份云南改良稻种和77份元阳地方稻种采用程氏指数法进行籼粳分类,比色法测定抗性淀粉、γ-氨基丁酸和总黄酮含量,并用SPSS软件对数据进行统计分析,结果表明:(1)总体抗性淀粉含量籼型偏籼偏粳粳型,γ-氨基丁酸含量则相反,黄酮含量与籼粳分化的关系不明显;(2)抗性淀粉、总黄酮含量有色米无色米,γ-氨基丁酸含量无色米有色米。总体功能性成分含量有色米无色米,籼稻粳稻,糙米精米,地方种改良种,有色、籼型糙米功能性成分最高,揭示了籼粳分化和米色与抗性淀粉、γ-氨基丁酸与总黄酮含量的关系。     

Wx基因与SSⅢ-2基因互作对稻米蒸煮食味品质的影响

为了探究蜡质基因(Wx)与可溶性淀粉合成酶Ⅲ-2基因(SSⅢ-2)等位变异对稻米品质的影响,以籼型高直链淀粉恢复系CG133R和糯性‘爪哇稻22’为亲本杂交,在其F3群体选择仅在Wx和SSⅢ-2基因位点存在多态性的单株为材料,分析各基因型材料的理化指标和粘度速测仪谱特征值。结果表明:(1)SSⅢ-2基因为I型时,Wx基因第一内含子多态性对表观直链淀粉含量有极显著影响。SSⅢ-2基因为Ⅱ型时,Wx基因第一内含子多态性对表观直链淀粉含量和成糊温度有极显著影响。(2)Wxa背景下,SSⅢ-2基因对稻米品质无显著影响;Wxb背景下,SSⅢ-2基因对糊化温度和粘度速测仪谱中最高粘度、崩解值、成糊温度有极显著影响。(3)Wx和SSⅢ-2基因共同作用极显著影响水稻表观直链淀粉含量、糊化温度、最高粘度、崩解值和成糊温度,说明Wx和SSⅢ-2基因之间存在互作,且Wx基因对SSⅢ-2基因具有显性上位性,Wx基因大量表达会遮盖SSⅢ-2基因对稻米品质的效应。     

地中海地区稻种资源的籼粳分类及遗传多样性

利用SSR标记及程氏综合指数法分析了109份从地中海引进的水稻种质资源的遗传多样性和籼粳类型,同时利用籼粳测交法分析了其中37份资源的籼粳亲和性.结果表明,大部分引进的水稻种质属粳稻类型,基于SSR聚类、程氏综合指数法分析所确定的粳型品种数分别占引进种质的80.73%和77.98%,基于籼粳亲和性分类所确定的粳型品种数占供试37份资源的75.68%.地中海稻种资源具有较高的遗传多样性,平均有效等位基因数为3.84个,Nei多样性指数平均值为0.482,其中籼稻群与粳稻群的Nei多样性指数分别为0.459和0.340,籼稻遗传多样性高于粳稻.研究结果对于科学引进、合理保存和有效利用国外水稻种质改良国内水稻品种具有指导意义.     

香稻资源遗传多样性的比较

利用60个水稻SSR标记, 对来自国内外的370份香稻材料的遗传多样性进行了比较分析。结果共检测到361个等位基因, 每个位点的等位基因变幅为2~10个, 平均Nei基因多样性指数(He)为0.663, 变幅为0.104(RM308)~0.885(RM2634)。籼粳亚种间的遗传多样性具有明显差异, 籼稻的等位基因数和Nei基因多样性指数均高于粳稻。地方品种的遗传多样性高于选育品种, 选育品种等位基因数仅为地方品种的86.5%。分子方差分析表明, 香稻材料中总变异的43.08%是由于亚种间的遗传差异引起的。不同稻区的遗传分化程度总体介于1.69%~14.40%之间。其中, 华南与西南、华中与西南地方品种间遗传差异的分化程度达显著水平。聚类分析将参试材料明显分为籼粳两大类, 同时地域相同(稻区)、相邻省份的香稻材料基本归为同一类群。     

籼稻和粳稻中蜡质基因座位上微卫星标记的多态性及其与直链淀粉含 …

稻米直链淀粉是在由蜡质基因Ｗｘ编码的颗粒结合淀粉合成酶（ＧＢＳＳ）的催化下合成的,最近,在Ｗｘ基因的区段内发现了一段多态性微卫星序列（ＣＴ）ｎ,对７４个非糯籼稻和粳稻材料的（ＣＴ）ｎ多态性进行了分析,并探讨了其与直链淀粉含量之间的关系,在７４个品种（系）中共发现７种（ＣＴ）ｎ片段（Ｗｘ等位基因）邓（ＣＴ）８,（ＣＴ）１０,（ＣＴ）１１,（ＣＴ）１６,（ＣＴ）１７,（ＣＴ）１８,（ＣＴ）１９,在籼粳     

优质稻米‘青香软粳’低直链淀粉含量形成分子机制的初步研究

Waxy（Wx）基因在调控直链淀粉含量形成过程中起着重要的作用,是稻米蒸煮食味品质的一个关键决定因素。在本项研究中,我们以直链淀粉含量为8.7%和10.2%的优质稻品种‘青香软粳’和‘南粳46’为主要研究对象,初步分析并探讨了这两个优质稻品种稻米低直链淀粉形成的分子调控机理。结果显示,虽然都为Wx-II型粳稻品种,‘南粳46’的Wx基因在启动子1773位置存在AA/CT的变异,‘南粳46’和‘青香软粳’的Wx基因在启动子＋693位置具有G/A位点多态性。转录水平分析表明,在‘南粳46’和‘青香软粳’稻米发育过程中,Wx基因的表达模式有较大的差异,可能与其启动子序列的多态性相关,AA/CT变异处于Wx基因的转录调控区。Wx基因启动子后＋693位点的多态性与已报道Wxmq多态性位点之一相同,引起Arg158/His158的变异;生物信息学软件分析表明,该位点处于底物进入Wx蛋白催化中心的袋口上,Arg158/His158位点的变异可能影响到底物进入Wx蛋白催化活性中心的速率,从而影响稻米直链淀粉的合成过程和含量。文章丰富了Wx基因多态性的研究,为进一步验证其核苷酸变异与稻米直链淀粉含量的相关性奠定了基础。     

回交重组自交系中SSⅢ-1、SBE3和PUL基因对稻米蒸煮食味品质的影响

该研究利用颗粒结合淀粉合成酶基因(Wxb)与可溶性淀粉合成酶Ⅱa基因(SSⅡ-3)均相同的籼型光温敏核不育系‘广占63S’和潜力恢复系CG173R为亲本,经过回交和多代自交,以构建的回交重组自交系(BILs)BC1F10代株系为供试材料,分析各株系的基因型组成及其蒸煮食味品质(ECQs)和RVA谱,以解析与品质相关微效基因的遗传效应。结果显示:(1)双亲在焦磷酸化酶大亚基基因(AGPlar)、分支酶基因Ⅲ(SBE3)、脱分支酶基因(PUL)、可溶性淀粉合成酶Ⅰ基因(SSⅠ)和可溶性淀粉合成酶SSⅢ-1基因(SSⅢ-1)的基因位点存在差异。(2)SSⅢ-1、SBE3和PUL基因分别在BC1F10代株系中存在单基因分离,SSⅢ-1和SBE3基因、SSⅢ-1和PUL基因在BC1F10代株系中均存在双基因的分离。(3)不同基因型及其互作与蒸煮食味品质(ECQs)中的表观直链淀粉含量(AAC)、胶稠度(GC)以及RVA谱的部分特征值存在显著或极显著的效应。(4)SSⅢ-1单基因只对AAC有极显著影响;SBE3基因和SSⅢ-1基因互作对AAC有极显著影响,对峰值时间(PeT)、成糊温度(PaT)、GC有显著性影响;PUL基因和SSⅢ-1基因互作对PeT、PaT和回复值(CSV)有极显著影响,对最高粘度(PKV)、热浆粘度(HPV)、崩解值(BDV)、冷浆粘度(CPV)、消减值(SBV)、AAC和GC有显著影响。研究表明,在Wxb和SSⅡ-3基因背景下,参与淀粉合成的微效基因SSⅢ-1与SBE3和SSⅢ-1的互作效应极显著影响水稻AAC,SBE3和SSⅢ-1的互作效应与PUL和SSⅢ-1的互作效应显著影响GC,PUL和SSⅢ-1的互作效应极显著影响PaT,这些发现将对改良稻米品质和加快水稻优质育种具有重要意义。     

水稻亚种间杂交粒重及加工品质性状的遗传效应分析

用4个广亲和粳型品种和5个籼型品种为材料,按NCⅡ设计配制杂交组合,获得同一环境下的亲本及F_1植株上的籽粒群体(F_2),对其稻谷千粒重、糙米千粒重、出糙率、总精米率以及整精米率等粒重和加工品质性状进行测定,并按胚乳性状遗传模型和混合线性模型的分析方法对籼粳亚种间杂交稻粒重及加工品质性状的遗传效应进行了研究,结果表明:籼粳交籽粒的粒重及各加工品质性状同时受到胚乳直接基因效应、母体基因效应以及微弱的细胞质效应的影响,但其主要受制于母体加性效应,并且存在一定的胚乳杂种优势和母体杂种优势;不同亲本品种对于粒重及加工品质性状的遗传改良具有不同的作用.     

可溶性淀粉合成酶与稻米淀粉精细结构关系的研究进展

支链淀粉是稻米淀粉的最主要组成部分,不同水稻品种间支链淀粉分子聚合度及分支链链长与分布有所不同,从而影响了稻米的品质。本文简要回顾了稻米淀粉的结构及其主要合成酶类,并以可溶性淀粉合成酶为重点,综述了水稻中可溶性淀粉合成酶4个亚家族不同同工型在决定淀粉精细结构中的作用,同时对相关基因的表达等方面也做了论述,旨在为水稻淀粉合成调控及品质改良提供参考。     

Preparation of hair for measurement of elements by inductively coupled plasma-mass spectrometry (ICP-MS)

The preparation of hair for the determination of elements is a critical component of the analysis procedure. Open-beaker, closedvessel microwave, and flowthrough microwave digestion are methods that have been used for sample preparation and are discussed. A new digestion method for use with inductively coupled plasma-mass spectrometry (ICP-MS) has been developed. The method uses 0.2 g of hair and 3 mL of concentrated nitric acid in an atmospheric pressurelow-temperature microwave digestion (APLTMD) system. This preparation method is useful in handling a large numbers of samples per day and may be adapted to hair sample weights ranging from 0.08 to 0.3 g. After digestion, samples are analyzed by ICP-MS to determine the concentration of Li, Be, B, Na, Mg, Al, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, As, Se, Rb, Sr, Zr, Mo, Pd, Ag, Cd, Sn, Sb, I, Cs, Ba, Pt, Au, Hg, Tl, Pb, Bi, Th, and U. Benefits of the APLTMD include reduced contamination and sample handling, and increased precision, reliability, and sample throughput.     

日本北海道虻类雌性外生殖器形态(双翅目：虻科)(英文)

【目的】利用日本北海道虻类评估和验证外生殖器在分类学上的意义。【方法】将虻类成虫标本浸渍在生理盐水中并置于双目显微镜下通过针和镊子在培养皿中进行解剖并绘图,观察第9背板、第10背板、尾叶、第8腹板、受精囊、受精囊管及生殖叉器的形态特征。【结果】在日本北海道共记录了虻科(Tabanidae) 3亚科7属38种。我们观察并描述了3亚科其中的6属24种的雌性外生殖器的主要特征。亚科之间存在明显差异;然而在一般情况下属之间很难建立一种方法来确定共同点;种之间只有在斑虻属Chrysops中有相似之处,其他属中则比较多样化。因此,亚科鉴定根据第9背板、第8腹板及受精囊足以进行区分,属及种鉴定需要结合第9背板、第10背板、尾叶、第8腹板、受精囊、受精囊管及生殖叉器各自的特征组合在一起才能区分开来。我们也制作了虻类外生殖器的检索表。【结论】和许多其他昆虫一样,外生殖器是虻科的重要分类特征,对于促进分类学和系统学的发展具有重要意义。本研究首次对分布在日本北海道的虻科雌性外生殖器进行了系统研究。     

外泌体在白血病中的重要调控作用

目前,白血病复发是患者死亡的主要原因之一。肿瘤细胞和微环境的相互作用,以及隐匿在骨髓中的肿瘤干细胞,促进了白血病的复发和向淋巴组织的转移,因此白血病的治疗、转移和复发问题受到广泛关注。外泌体是由绝大多数细胞分泌的双层脂质膜囊泡,可以调控细胞间的交流和信息传递。在白血病细胞、基质细胞和内皮细胞之间的相互联系中都涉及到外泌体,白血病细胞来源的外泌体存在于白血病患者的血浆中,能把其携带的白血病相关抗原及微小RNA呈递给靶细胞,促进白血病肿瘤细胞的增殖,有助于肿瘤细胞实现免疫逃避,保护白血病细胞抵抗化疗药物导致的细胞毒性作用,促进血管生成及肿瘤细胞的迁移。因此,外泌体与白血病的转移、治疗及预后密切相关,可以用来检测和监测白血病的进展。本文综述了外泌体的来源、形成与分泌机制,以及外泌体在白血病发生前、发展中、预后和免疫治疗中所扮演的重要角色。     

Assessing burrowing, nest construction, and hoarding in mice

Deterioration in the ability to perform "Activities of daily living" (ADL) is an early sign of Alzheimer's disease (AD). Preclinical behavioural screening of possible treatments for AD currently largely focuses on cognitive testing, which frequently demands expensive equipment and lots of experimenter time. However, human episodic memory (the most severely affected aspect of memory in AD) is different to rodent memory, which seems to be largely non-episodic. Therefore the present ways of screening for new AD treatments for AD in rodents are intrinsically unlikely to succeed. A new approach to preclinical screening would be to characterise the ADL of mice. Fortuitously, several such assays have recently been developed at Oxford, and here the three most sensitive and well-characterised are presented. Burrowing was first developed in Oxford. It evolved from a need to develop a mouse hoarding paradigm. Most published rodent hoarding paradigms required a distant food source to be linked to the home cage by a connecting passage. This would involve modifying the home cage as well as making a mouse-proof connecting passage and food source. So it was considered whether it would be possible to put the food source inside the cage. It was found that if a container was placed on the floor it was emptied by the next morning., The food pellets were, however, simply deposited in a heap at the container entrance, rather than placed in a discrete place away from the container, as might be expected if the mice were truly hoarding them. Close inspection showed that the mice were performing digging ("burrowing") movements, not carrying the pellets in their mouths to a selected place as they would if truly hoarding them. Food pellets are not an essential substrate for burrowing; mice will empty tubes filled with sand, gravel, even soiled bedding from their own cage. Moreover, they will empty a full tube even if an empty one is placed next to it. Several nesting protocols exist in the literature. The present Oxford one simplifies the procedure and has a well-defined scoring system for nest quality. A hoarding paradigm was later developed in which the mice, rather than hoarding back to the real home cage, were adapted to living in the "home base" of a hoarding apparatus. This home base was connected to a tube made of wire mesh, the distal end of which contained the food source. This arrangement proved to yield good hoarding behaviour, as long as the mice were adapted to living in the "home base" during the day and only allowed to enter the hoarding tube at night.     

Genetic Manipulation in Δku80 Strains for Functional Genomic Analysis of Toxoplasma gondii

Targeted genetic manipulation using homologous recombination is the method of choice for functional genomic analysis to obtain a detailed view of gene function and phenotype(s). The development of mutant strains with targeted gene deletions, targeted mutations, complemented gene function, and/or tagged genes provides powerful strategies to address gene function, particularly if these genetic manipulations can be efficiently targeted to the gene locus of interest using integration mediated by double cross over homologous recombination.Due to very high rates of nonhomologous recombination, functional genomic analysis of Toxoplasma gondii has been previously limited by the absence of efficient methods for targeting gene deletions and gene replacements to specific genetic loci. Recently, we abolished the major pathway of nonhomologous recombination in type I and type II strains of T. gondii by deleting the gene encoding the KU80 protein^1,2. The Δku80 strains behave normally during tachyzoite (acute) and bradyzoite (chronic) stages in vitro and in vivo and exhibit essentially a 100% frequency of homologous recombination. The Δku80 strains make functional genomic studies feasible on the single gene as well as on the genome scale^1-4.Here, we report methods for using type I and type II Δku80Δhxgprt strains to advance gene targeting approaches in T. gondii. We outline efficient methods for generating gene deletions, gene replacements, and tagged genes by targeted insertion or deletion of the hypoxanthine-xanthine-guanine phosphoribosyltransferase (HXGPRT) selectable marker. The described gene targeting protocol can be used in a variety of ways in Δku80 strains to advance functional analysis of the parasite genome and to develop single strains that carry multiple targeted genetic manipulations. The application of this genetic method and subsequent phenotypic assays will reveal fundamental and unique aspects of the biology of T. gondii and related significant human pathogens that cause malaria (Plasmodium sp.) and cryptosporidiosis (Cryptosporidium).     

Staining protocols for human pancreatic islets

Estimates of islet area and numbers and endocrine cell composition in the adult human pancreas vary from several hundred thousand to several million and beta mass ranges from 500 to 1500 mg. With this known heterogeneity, a standard processing and staining procedure was developed so that pancreatic regions were clearly defined and islets characterized using rigorous histopathology and immunolocalization examinations. Standardized procedures for processing human pancreas recovered from organ donors are described in part 1 of this series. The pancreas is processed into 3 main regions (head, body, tail) followed by transverse sections. Transverse sections from the pancreas head are further divided, as indicated based on size, and numbered alphabetically to denote subsections. This standardization allows for a complete cross sectional analysis of the head region including the uncinate region which contains islets composed primarily of pancreatic polypeptide cells to the tail region. The current report comprises part 2 of this series and describes the procedures used for serial sectioning and histopathological characterization of the pancreatic paraffin sections with an emphasis on islet endocrine cells, replication, and T-cell infiltrates. Pathology of pancreatic sections is intended to characterize both exocrine, ductular, and endocrine components. The exocrine compartment is evaluated for the presence of pancreatitis (active or chronic), atrophy, fibrosis, and fat, as well as the duct system, particularly in relationship to the presence of pancreatic intraductal neoplasia. Islets are evaluated for morphology, size, and density, endocrine cells, inflammation, fibrosis, amyloid, and the presence of replicating or apoptotic cells using H&E and IHC stains. The final component described in part 2 is the provision of the stained slides as digitized whole slide images. The digitized slides are organized by case and pancreas region in an online pathology database creating a virtual biobank. Access to this online collection is currently provided to over 200 clinicians and scientists involved in type 1 diabetes research. The online database provides a means for rapid and complete data sharing and for investigators to select blocks for paraffin or frozen serial sections.     

A phylogenetic analysis of 100+ genera and 50+ families of euasterids based on morphological and molecular data with notes on possible higher level morphological synapomorphies

 A data matrix of 143 morphological and chemical characters for 142 genera of euasterids according to the APG system was compiled and complemented with rbcL and ndhF sequences for most of the genera. The data were subjected to parsimony analysis and support was assessed by bootstrapping. Strict consensus trees from analyses of morphology alone and morphology + rbcL + ndhF are presented. The morphological data recover several groups supported by molecular data but at the level of orders and above relationships are only superficially in agreement with molecular studies. The analyses provide support for monophyly of Gentianales, Aquifoliales, Apiales, Asterales, and Dipsacales. All data indicate that Adoxaceae are closely related to Dipsacales and hence they should be included in that order. The trees were used to assess some possible morphological synapomorphies for euasterids I and II and for the orders of the APG system. Euasterids I are generally characterised by opposite leaves, entire leaf margins, hypogynous flowers, “early sympetaly” with a ring-shaped corolla primordium, fusion of stamen filaments with the corolla tube, and capsular fruits. Euasterids II often have alternate leaves, serrate-dentate leaf margins, epigynous flowers, “late sympetaly” with distinct petal primordia, free stamen filaments, and indehiscent fruits. It is unclear which of these characters represent synapomorphies and symplesiomorphies for the two groups, respectively, and there are numerous expections to be interpreted as reversals and parallelisms. Received August 28, 2000 Accepted August 7, 2001     

A Microplate Assay to Assess Chemical Effects on RBL-2H3 Mast Cell Degranulation: Effects of Triclosan without Use of an Organic Solvent

Mast cells play important roles in allergic disease and immune defense against parasites. Once activated (e.g. by an allergen), they degranulate, a process that results in the exocytosis of allergic mediators. Modulation of mast cell degranulation by drugs and toxicants may have positive or adverse effects on human health. Mast cell function has been dissected in detail with the use of rat basophilic leukemia mast cells (RBL-2H3), a widely accepted model of human mucosal mast cells^3-5. Mast cell granule component and the allergic mediator β-hexosaminidase, which is released linearly in tandem with histamine from mast cells⁶, can easily and reliably be measured through reaction with a fluorogenic substrate, yielding measurable fluorescence intensity in a microplate assay that is amenable to high-throughput studies¹. Originally published by Naal et al.¹, we have adapted this degranulation assay for the screening of drugs and toxicants and demonstrate its use here.Triclosan is a broad-spectrum antibacterial agent that is present in many consumer products and has been found to be a therapeutic aid in human allergic skin disease^7-11, although the mechanism for this effect is unknown. Here we demonstrate an assay for the effect of triclosan on mast cell degranulation. We recently showed that triclosan strongly affects mast cell function². In an effort to avoid use of an organic solvent, triclosan is dissolved directly into aqueous buffer with heat and stirring, and resultant concentration is confirmed using UV-Vis spectrophotometry (using ε₂₈₀ = 4,200 L/M/cm)¹². This protocol has the potential to be used with a variety of chemicals to determine their effects on mast cell degranulation, and more broadly, their allergic potential.     

Automated High-throughput Behavioral Analyses in Zebrafish Larvae

We have created a novel high-throughput imaging system for the analysis of behavior in 7-day-old zebrafish larvae in multi-lane plates. This system measures spontaneous behaviors and the response to an aversive stimulus, which is shown to the larvae via a PowerPoint presentation. The recorded images are analyzed with an ImageJ macro, which automatically splits the color channels, subtracts the background, and applies a threshold to identify individual larvae placement in the lanes. We can then import the coordinates into an Excel sheet to quantify swim speed, preference for edge or side of the lane, resting behavior, thigmotaxis, distance between larvae, and avoidance behavior. Subtle changes in behavior are easily detected using our system, making it useful for behavioral analyses after exposure to environmental toxicants or pharmaceuticals.