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1.
为弥补传统形态分类方法的不足,探究应用DNA条形码技术进行分子生物学鉴定的可行性,本研究用DNA条形码技术检测了青海省海东地区3目6科14属18种110只小型兽类的COI基因部分序列。分析所测COI基因序列可知:种内遗传距离≤3%,种间遗传距离5-10%,属间遗传距离12-19%,种间遗传距离显著大于种内遗传距离。NJ树显示同种个体聚为有很高支持度的单一分支。有6个个体(4只黄胸鼠、2只小家鼠)在现场鉴定中被误定为其他种类。研究结果表明使用条形码技术能纠正形态学鉴定中的错误,也说明动物线粒体COI基因是一个有效的DNA条形码标准基因。  相似文献   

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[目的]利用分子生物学手段探索裳卷蛾变形孢虫的遗传发育地位.[方法]微孢子虫的SSUrRNA序列是构建系统发育进化树的重要工具.试验通过T-A克隆法对裳卷蛾变形孢虫(Vairimorphaceraces)SSU rRNA核心序列进行了克隆,并采用近邻法构建了系统发育进化树.[结果]克隆得到了长为1228bp的核苷酸序列(GenBank EU267796).系统发育分析结果表明:裳卷蛾变形孢虫与分离于小菜蛾(Plutella xylostella)的Vairimorpha sp.Germany(GenBank AF124331)和Vairimorphaimperyecta(GenBank AJ131645)相似性最高,它们在系统发育进化树中与寄主为鳞翅目昆虫的Nosema属聚为一类,与纳卡变形孢虫(Vairimorpha necatrix)为代表的Vairimorpha属为相邻集.[结论]结合其生物学特征,裳卷蛾变形孢虫确实为Vairimorph a属的成员,但根据系统发育分析归入Nosematidae科可能更为合适.  相似文献   

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昆虫病原线虫资源概况和分类技术进展   总被引:7,自引:0,他引:7  
丘雪红  韩日畴 《昆虫学报》2007,50(3):286-296
昆虫病原线虫是具有重要潜在应用价值的害虫生物防治资源,主要包括斯氏线虫科(Steinernematidae)的斯氏线虫属Steinernema与新斯氏线虫属Neosteinernema线虫和异小杆线虫科(Heterorhabditidae)的异小杆线虫属Heterorhabditis线虫。近10年来,分子生物学方法与传统的形态学方法相结合应用到线虫的鉴定与分类,昆虫病原线虫的分类进入稳定与发展时期,越来越多的新种或品系被发现及应用于生物防治。目前已描述的昆虫病原线虫种类达65种,其中斯氏线虫属52种,新斯氏线虫属1种,异小杆线虫属12种。本文整理列出了迄今报道的昆虫病原线虫种类及其来源,并综述了昆虫病原线虫分类现状以及鉴定与分类方法上的研究进展,重点阐述了分子生物学技术在昆虫病原线虫鉴定与分类的应用状况。  相似文献   

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蚋的种类繁多,其不同发育虫期在形态学上具有高度的相似性,通过形态学特征对虫株进行鉴定具有极大的困难,且目前尚无公认的分类系统。从分子水平结合形态学特征对蚋科类群进行整理,应能使蚋科昆虫鉴定更为准确,分类系统更能反映其生物谱系。以COⅠ基因的特定区段作为"条形码"为生物编码,可实现物种鉴定的便捷、准确及自动化。本研究对15株蚋科昆虫进行了形态学鉴定及基于COⅠ基因序列的系统发育分析。研究中共采集并成功羽化出蚋科虫株15株,其中14株完成形态学鉴定,COⅠ基因序列分析验证了形态学鉴定结果;L1虫株因操作过程中成虫尾器被破坏,未完成完整形态学鉴定,COⅠ基因序列分析提示其可能为一未知新种或未报道过COⅠ基因序列的已知种。研究结果显示,蚋的形态学鉴定极度依赖鉴定者的经验和熟练的技术,严重制约了蚋的鉴定、分类研究的发展,COⅠ基因序列分析能较好建立蚋亚属内种间关系。  相似文献   

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灵芝栽培品种常出现同名异物或同物异名的现象,依赖于灵芝的形态学特征鉴定物种的传统分类方法不足以鉴定物种的种间和种内差异。为开发简便而准确的分子水平灵芝属物种鉴定方法,以常用于种属鉴定的核糖体内转录间隔区(ITS)、微管蛋白基因(β-tubulin)片段、大亚基核糖体DNA(LSU)片段和基因编码RNA聚合酶Ⅱ第二大亚基(RPB2)片段4个DNA条形码,对灵芝属10个物种的44份菌株进行PCR扩增和测序,比较4个条形码的扩增成功率和变异率,根据种内、种间遗传距离差异分析筛选特异性的DNA条形码间隔(DBG),并利用单独及联合条形码构建系统发育树验证筛选的DBG鉴定灵芝属物种的准确性。研究结果表明:β-tubulin和LSU片段的PCR扩增成功率均达100%,ITS和RPB2片段分别为95.35%和90.91%;对比ITS和LSU片段,β-tubulin和RPB2片段的种内最大遗传距离分别小于各自的种间最小遗传距离,存在明显的DBG,有利于准确对物种进行种间鉴定;利用ITS、β-tubulin和RPB2片段分别构建的系统发育树均能使灵芝属10个物种的所有个体聚为1个单系分支,而LSU片段不...  相似文献   

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2018年9月至2019年10月,对新疆乌鲁木齐市区及巴楚县的鱼类进行寄生虫病原调查过程中,在斑点叉尾鮰(Ictalurus punctatus)和云斑(鱼回)(I. nebulosus)鳃部发现有单殖吸虫寄生,两种鱼所寄生的虫种形态基本一致,仅连接片形态稍有差异,通过形态学鉴定为锚首虫科(Ancyrocephalidae)趋(鱼回)虫属(Ligictaluridus)的普氏趋(鱼回)虫(L.pricei)。为验证形态鉴定的准确性,扩增了寄生虫的28S rDNA序列,并进行了系统发育分析。结果显示,两种鱼所寄生的单殖吸虫与普氏趋(鱼回)虫的相似度均达98%以上,在系统进化树中紧密聚为一支,置信度均为100;同时,两种虫与普氏趋(鱼回)虫间的遗传距离数值接近于零,表现出了很高的相似度和亲缘关系。因此根据形态特征和系统发育分析,确定这两种鱼感染的是同一种寄生虫。研究结果可为新疆人工养殖(鱼回)科鱼类的病害防治提供依据。  相似文献   

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作者等于1984年8月以来在湖南南部郴州市郊区水田中采到一种寄生于三带喙库蚊(Culex tritaeniorhynchus)幼虫胸内的索线虫,自然感染率较高,寄生较普遍。经鉴定属于线虫纲(Nematoda)嘴刺目(Enoplida),索科(Mermithidae),罗索属(Romanomermis)的一新种。文中量度除标明外,均以μm为单位。  相似文献   

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根据传统形态学特征的系统分类学研究,将瘦尾虫属(Uroleptus)归入尾柱目(Urostylida).但是,基于单基因和多基因联合的分子系统发育学分析支持瘦尾虫属与散毛目内部类群的亲缘关系更近.为进一步探讨旋唇纲(Spirotrichea)内部类群的系统发育关系以及瘦尾虫属的系统发育地位,我们对四种旋唇纲纤毛虫(澳大利亚速体虫(Notohymena australis)、瘦尾虫属未定种(Uroleptus sp.)、弹跳虫属未定种(Halteria sp.)和楯纤虫属未定种(Aspidisca sp.))进行单细胞转录组测序,并基于151个直系同源基因的51 596个氨基酸位点对旋唇纲开展更全面的系统发育基因组学分析.分析结果支持旋唇纲中四个亚纲单系:寡毛亚纲与环毛亚纲聚为姐妹枝,腹毛亚纲与这两个亚纲的亲缘关系更近,游仆亚纲位于旋唇纲的基部.尾柱目非单系,瘦尾虫属与散毛目中的尖毛虫科聚为一支,系统发育基因组学分析结果支持瘦尾虫属归于散毛目.  相似文献   

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2018年9月至2019年10月,对新疆乌鲁木齐市区及巴楚县的鱼类进行寄生虫病原调查过程中,在斑点叉尾鮰(Ictalurus punctatus)和云斑(鱼回)(I. nebulosus)鳃部发现有单殖吸虫寄生,两种鱼所寄生的虫种形态基本一致,仅连接片形态稍有差异,通过形态学鉴定为锚首虫科(Ancyrocephalidae)趋(鱼回)虫属(Ligictaluridus)的普氏趋(鱼回)虫(L.pricei)。为验证形态鉴定的准确性,扩增了寄生虫的28S rDNA序列,并进行了系统发育分析。结果显示,两种鱼所寄生的单殖吸虫与普氏趋(鱼回)虫的相似度均达98%以上,在系统进化树中紧密聚为一支,置信度均为100;同时,两种虫与普氏趋(鱼回)虫间的遗传距离数值接近于零,表现出了很高的相似度和亲缘关系。因此根据形态特征和系统发育分析,确定这两种鱼感染的是同一种寄生虫。研究结果可为新疆人工养殖(鱼回)科鱼类的病害防治提供依据。  相似文献   

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【目的】小毛瓢虫属Scymnus Kugelann昆虫主要捕食蚜虫、蚧虫等害虫,是一类经济上重要的天敌昆虫。目前针对小毛瓢虫属的系统发育研究尚属空白,亚属之间的系统演化关系尚不明确,为了建立合理的分类系统,亟需对小毛瓢虫属的亲缘关系进行研究和探讨。【方法】以华南农业大学馆藏的小毛瓢虫属5亚属共44种为研究对象,采用PCR技术对12S, 16S和28S rRNA基因的部分序列进行扩增;运用MEGA 7.0分析了小毛瓢虫属内12S, 16S和28S rRNA基因的碱基组成,基于K2P模型计算了小毛瓢虫属44种的种间遗传距离;采用最大似然法(maximum-likelihood, ML)和贝叶斯推断法(Bayesian-inference, BI)构建该属的系统发育树。【结果】扩增获得小毛瓢虫属44种的12S rRNA基因序列平均长度为356 bp, 16S rRNA基因序列平均长度为351 bp, 28S rRNA基因序列平均长度为315 bp;序列分析表明,12S rRNA基因的A, T, G和C平均含量分别为38.8%, 43.5%, 11.9%和5.8%, 16S rRNA基因的A, T, G和C平均含量分别为37.6%, 40.3%, 14.4%和7.7%, 28S rRNA基因的A, T, G和C平均含量分别为26.7%, 18.3%, 31.4%和23.5%;基于联合序列分析的种间遗传距离为0.004~0.276,平均遗传距离为0.115。系统发育分析结果表明,小毛瓢虫属为单系起源,而小毛瓢虫亚属Scymnus(Scymnus) Kugelann、毛瓢虫亚属Scymnus(Neopullus) Sasaji、小瓢虫亚属Scymnus(Pullus) Mulsant和拟小瓢虫亚属Scymnus(Parapullus) Yang均为并系起源。【结论】基于12S, 16S和28S rRNA基因序列的小毛瓢虫属系统发育分析显示传统的形态学分类体系与基于分子数据分析的结果部分不一致,这表明应该对该属内各亚属的鉴别特征进行全面检视,筛选并确立各亚属的形态指标,同时也表明该属内的亚属分类单元需重新厘定。  相似文献   

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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.  相似文献   

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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  相似文献   

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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.  相似文献   

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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.  相似文献   

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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.
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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).  相似文献   

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