华山松不同生态位上蚜虫的快速鉴定——基于DNA条形码

DNA条形码技术是利用一个短的DNA标记对生物进行快速鉴定。模糊式快速鉴定则是在当前数据库信息不足的情况下利用DNA条形码技术,结合形态测量学在短时间内完成大量样品的鉴定。华山松(Pinus armandii Franch)是我国特有的重要用材树种之一,蚜虫是华山松的重要害虫,对其快速准确的鉴定有助于害虫的准确而有效的防治。本文以华山松上的蚜虫为研究对象,基于线粒体COⅠ序列构建了NJ树,采自不同地区华山松上的蚜虫样品分为13个支,各节点的支持率均达到90%以上,蚜虫种内个体间平均遗传距离在0⁰.0536之间,种间遗传距离在0.05540.0536之间,种间遗传距离在0.0554⁰.1444之间。分析结果表明,不同的蚜虫种类占据华山松上不同的部位,取食部位多样性的分化是蚜虫物种竞争并占据不同生态位的结果。模糊式快速鉴定不仅能够快速的区分华山松上的不同蚜虫物种,而且有助于发现隐存分类单元。在当前数据库信息量不足的情况下,模糊式快速鉴定是在短时间内解决大量样品物种分类的行之有效的方法。     

SSR标记鉴定浙江省主要无性系茶树品种的研究

为促进浙江省茶树育种的发展,利用SSR引物对浙江省茶树育成品种的遗传多样性进行了研究,筛选出可用于鉴别浙江省茶树品种的核心鉴定引物和标准品种,并进一步应用于未知茶苗身份鉴定。首先,利用35对SSR引物研究了36个茶树育成品种,并进行聚类分析;然后,根据电泳谱带和基因型筛选出核心鉴定引物和标准品种;最后,对4株未知茶苗进行了身份鉴定。结果表明:共有34对引物表现出多态性,各品种基本按遗传背景聚类,重复样本间遗传距离介于0~0.094;有10对引物确定为核心鉴定引物,8个品种为标准品种;4株未知身份茶苗中,NH-01属于乌牛早品种,另外3株并非浙江现有品种。本研究认为,核心鉴定引物在两个浙江育成品种间差异引物对≥2时,应判定为不同品种;差异引物对≤1时,应判定为相同品种或极相似品种,必要时应引入其余24对引物计算遗传距离进一步验证,遗传距离>0.140判定为不同品种,遗传距离≤0.140判定为同一品种。     

应用RAPD标记分析黑麦属品种的遗传多样性

四川农业大学小麦研究所侯永翠、郑有良、魏育明等研究人员对黑麦遗传多样性课题作了研究。他们采用随机扩增多态性DNA(RAPD)标记 ,对黑麦属 (SecaleL) 7个品种共 1 2份材料进行了遗传多样性检测 ,发现被检测材料间RAPD标记多态性较高 ,在 4 0个随机引物中 ,有 2 5个引物约占整个的 6 2 .5 %的扩增产物具有多态性。这 2 5个中共扩增出 1 6 7条带 ,其中 89条带约占 5 3.2 %具有多态性 ,每个引物可扩增出 1～ 1 0条多态性带 ,平均为 3～ 6条。RAPD标记遗传距离GD变异范围为 0 .1 382～ 0 .4 5 1 2 ,平均为 0 .2 71 2。通过聚类分析表…     

用RAPD技术探讨冬青属苦丁茶的遗传差异、亲缘关系与分类地位

利用随机扩增多态性DNA (RAPD)技术对 2 2份冬青属苦丁茶不同种质材料的遗传变异进行了研究。 4 0个 10 bp的引物用于多态性检测 ,从中筛选出了 2 7个多态性良好的引物。用该 2 7个引物对上述 2 2份种质材料进行PCR扩增 ,共得到 4 45条DNA谱带 ,其中多态性带4 32条 ,占 97 0 8%。根据扩增结果计算了各份材料之间的遗传距离 ,并用UPGMA构建了聚类树状图。分析结果表明 :2 2份供试材料分成 4类 5组 ,第Ⅰ类为Ilexpentagona (分为A、B两组 :A组为新变种var mashanensisG .M .L .;B组为原变种var pentagona) ,第Ⅱ类为I kudingcha,第Ⅲ类为I latifolia ,第Ⅳ类为I cornuta ;第Ⅱ ,Ⅲ ,Ⅳ三类各有一组材料组成。物种的差异、亲缘关系以及同一物种内不同种质材料在起源地域上的差异均可从系统树中反映出来。RAPD分子标记的结果可作为判断冬青属苦丁茶种质资源材料的起源地域、遗传差异、亲缘关系以及种级水平和种下分类鉴定的重要参考依据     

柚类种质资源RAPD标记研究的引物筛选

利用 10 0个 10碱基随机引物 ,对柚类 4个品种酸柚、沙田柚、文旦柚和泰国柚进行了RAPD标记的引物筛选研究 ,结果为无扩增产物的引物 18个 ,在 1、 2、 3个和所有 4个样品中有扩增产物的引物数分别为 2 0、 13、 2 5和 2 4个 ;读取了 12个在所有 4个样品中都有扩增产物的引物的 RAPD带 ,计算了样品间 RAPD多态性位点的百分率为 60 .6% ;计算了样品间的相似系数和遗传距离 ,并对遗传距离进行了 UPGMA聚类分析 ,论证了利用所筛选出的引物对柚类进行 RAPD标记研究的可行性和可靠性     

采用RAPD技术探讨花椒的遗传多样性及其与环境的关系

采用RAPD分子标记方法分析11个花椒品种的遗传多样性,以及遗传多样性与环境因素的相关性。从60条随机引物中筛选出10条引物,共扩增出67条带,平均每个引物扩增出6．7条,其中56条具有多态性,多态比例为84％。根据品种间的遗传距离构建的聚类分析树状图,11个花椒品种的相似系数在0．08-0．92之间,可分为2个类群,这种分类与花椒的叶的外形分类结果一致。不同地域种植的同一品种材料遗传距离较大,显示花椒的遗传多样性与地域分布有关系。     

甘草亲缘关系的RAPD鉴定

以不同地区的3种15组甘草(Glycyrrhiza uralensis、G．infleta、G．glebra)种子为材料,探讨RAPD分子标记在研究、鉴定甘草亲缘关系中的可行性。从50个随机引物中筛选出9个有效引物,9个引物共扩增出961条DNA带,其中多态性条带811条,占总扩增条带的84．4％。对扩增出来的961条DNA带进行分析,结果表明：15组甘草植物的平均遗传距离为0．41,其中采自甘肃民勤野生甘草与采自新疆布尔津乌拉尔野生甘草遗传距离最小,为0．26;而采自内蒙古杭锦旗上海升袖的野生甘草与采自青海贵德的乌拉尔野生甘草遗传距离最大,为0．63。由RAPD聚类分析结果得出15组甘草植物之间的亲缘关系与形态学分类结果存在差异。     

林麝和马麝随机扩增多态DNA的研究

用随机扩增多态 DNA(RAPD)技术对饲养的林麝和马麝进行分子遗传标记研究。在选用的42 种随机引物中, 有25种引物产生了清晰稳定的条带, 单个引物获得标记数在1～14 之间,平均每个个体获得168个RAPD标记 , 其中林麝、马麝特异性标记各5个,个体特异性标记有3个, 这些标记可用来鉴定种或个体。平均遗传距离在林麝种内为0.27±0.023, 马麝为0.105±0.013, 种间为0.241±0.02 , 种间差异显著大于种内差异。分析表明饲养马麝种内遗传多样性低, 为增强饲养马麝的生存力, 最好从不同种群中引入种麝进行繁殖。     

用SSR和AFLP技术分析花生抗青枯病种质遗传多样性的比较

由Ralstonia solanacearum E.F.Smith引起的青枯病是若干亚洲和非洲国家花生生产的重要限制因子,利用抗病品种是防治这一病害最好的措施。虽然一大批抗青枯病花生种质资源材料已被鉴定出来,但对其遗传多样性没有足够的研究,限制了在育种中的有效利用。本研究以31份对青枯病具有不同抗性的栽培种花生种质为材料,通过简单序列重复(SSR)和扩增片段长度多态性(AFLP)技术分析了它们的遗传多样性。通过78对SSR引物和126对AFLP引物的鉴定,筛选出能显示抗青枯病种质多态性的SSR引物29对和AFLP引物32对。所选用的29对多态性SSR引物共扩增91条多态性带,平均每对引物扩增3.14条多态性带;32对多态性AFLP引物共扩增72条多态性带,平均扩增2.25条多态性带。在所筛选引物中,4对SSR引物(14H06,7G02,3A8,16C6)和1对AFLP引物(P1M62)检测花生多态性的效果优于其他引物。SSR分析获得的31个花生种质的遗传距离为0.12-0.94,平均为0.53,而AFLP分析获得的遗传距离为0.06～0.57,平均为0.25,基于SSR分析的遗传距离大于基于AFLP分析的遗传距离,疏枝亚种组的遗传分化相对大于密枝亚种组。基于两种分析方法所获得的聚类结果基本一致,但SSR数据聚类结果与栽培种花生的形态分类系统更为吻合。根据分析结果,对构建青枯病抗性遗传图谱群体的核心亲本和抗性育种策略提出了建议。     

DNA条形码快速鉴定广州木槿蚜虫

为快速、准确鉴定木槿蚜虫,本文在广州市30个采样点采集了木槿蚜虫样本64份,利用DNA条形码技术获得了64份线粒体细胞色素C氧化酶亚基I(COI)基因的658 bp序列,同时利用形态鉴定和DAN条形码鉴定确定其中共包括5种蚜虫,棉蚜Aphis gossypii Glover、绣线菊蚜Aphis spiraecola Patch、苹果蚜Aphis pomi de Geer、月季长管蚜Sitobion rosivorum(Zhang)和桃蚜Myzus persicae(Sulzer)。所有样品的种内平均遗传距离为0.30%(0~2.30±0.36%),种间平均遗传距离为9.00%(3.30%~10.90±1.22%)。邻接法(neighbor-joining,NJ)构建的系统发育树显示采自30个采样点木槿上的5种蚜虫分别聚为一支,支持率达99%。所获DNA条形码对指导木槿的蚜虫防治有一定的指导意义。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Synthesis and antimicrobial studies of hydrazone derivatives of 4-[3-(2,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid and 4-[3-(3,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid

Microbial resistance to antibiotics is an unresolved global concern, which needs urgent and coordinated action. One of the guidelines of the Centers for Disease Control and Preventions (CDC) to combat antibiotic resistance is the development of new antibiotics to treat drug-resistant bacteria. In our effort to find new antibiotics, we report the synthesis and antimicrobial studies of 30 new pyrazole derivatives. These novel molecules have been synthesized by using readily available starting materials and benign reaction conditions. Some of these molecules have shown activity with MIC values as low as 0.78?µg/mL against four bacterial strains; Staphylococcus aureus, methicillin-resistant S. aureus, Bacillus subtilis, and Acinetobacter baumannii. Furthermore, active molecules are non-toxic to mammalian cell line.

     

Novel compounds with potent CDK9 inhibitory activity for the treatment of myeloma

Cyclin-dependent kinases (CDKs) and Polo-like kinases (PLKs) play key role in the regulation of the cell cycle. The aim of our study was originally the further development of our recently discovered polo-like kinase 1 (PLK1) inhibitors. A series of new 2,4-disubstituted pyrimidine derivatives were synthesized around the original hit, but their PLK1 inhibitory activity was very poor. However the novel compounds showed nanomolar CDK9 inhibitory activity and very good antiproliferative effect on multiple myeloma cell lines (RPMI-8226).