洞庭湖四种黄颡鱼基因组DNA遗传多样性的RAPD分析

以洞庭湖瓦氏黄颡鱼、光泽黄颡鱼、长须黄颡鱼、普通黄颡鱼的基因组DNA为材料对 4种黄颡鱼进行了遗传多样性随机扩增多态性DNA(RAPD)分析。通过筛选的 90个引物对 4种黄颡鱼基因组DNA的扩增 ,获得了 36个有效引物 ,并计算出了 4种黄颡鱼群体间的遗传相似系数和遗传距离 ,遗传距离最大的为普通黄颡鱼和瓦氏黄颡鱼 (D =0 9895 ) ,遗传距离最小的为普通黄颡鱼和光泽黄颡鱼 (D =0 672 0 )。同时运用聚类分析 (UPGMA)的方法建立了 4种黄颡鱼的聚类图。     

瓦氏黄颡鱼线粒体全基因组序列分析及系统进化

鲿科鱼类种类繁多, 外形相似, 形态学分类较为困难。为了给鲿科鱼类乃至鲇形目鱼类的系统进化研究积累基础资料, 文章采用参照近缘物种线粒体基因组设计覆盖全基因组引物的方法, 利用16对引物对瓦氏黄颡鱼(Pelteobagrus vachelli)线粒体全基因组进行扩增, PCR产物转化到质粒后测序, 最终获得线粒体基因组全序列, 其全长为16 527 bp, 包括2个rRNA基因、22个tRNA基因、13个编码蛋白质基因和一个非编码控制区。瓦氏黄颡鱼(P. vachelli)线粒体基因组结构和基因排列顺序与现已公布的鲇形目鱼类完全一致, 序列分析表明, 与鲇形目其他种属间具有较高的同源性, 与拟鲿属的同源性最高(91%)。利用鲇形目共4科6属9种及3个外群的线粒体全基因组序列, 从线粒体基因组水平探讨了鲿科鱼类及其在鲇形目的系统进化地位, 结果表明: 鲿科鱼类的瓦氏黄颡鱼(P. vachelli)、黄颡鱼(Pelteobagrus fulvidraco)、光泽黄颡鱼(Pelteobagrus nitidus)及越南拟鲿(Pseudobagrus tokiensis)构成一单系群; 拟鲿属与黄颡鱼属的关系较近; 黄颡鱼属中瓦氏黄颡鱼(P. vachelli)与光泽黄颡鱼(P.nitidus)的关系近于黄颡鱼(P. fulvidraco)。     

三峡水库光泽黄颡鱼年龄、生长与死亡特征研究

光泽黄颡鱼(Pelteobagrus nitidus Sauvage et Dabry)是三峡水库蓄水后的优势中小型底层鱼类之一,为解析其种群特征,基于2015—2016年在三峡水库采集的鱼类样本(n=2477),对其年龄与生长等进行了研究.光泽黄颡鱼的平均体长为(87.1±0.5)mm,不表现雌雄异形.库尾种群的平均...     

应用DNA分子标记鉴定黄颡鱼、瓦氏黄颡鱼及其杂交种的研究

为区分黄颡鱼（Pelteobagrus fulvidraco Richardson）、瓦氏黄颡鱼（Pelteobagrus vachelli Richardson）及其杂交种,前期研究构建了一个YY超雄黄颡鱼的BAC文库并筛选到了一个包含性别连锁标记Pf62-Y的BAC克隆。研究对该BAC克隆进行测序并鉴定到了一个新基因Inad-like,而且Inad-like的外显子序列在X和Y染色体上基本一致。通过黄颡鱼Inad-like的外显子序列及序列的保守性我们设计引物在瓦氏黄颡鱼中扩增获得了其部分内含子序列。通过内含子序列比对,发现瓦氏黄颡鱼比黄颡鱼少了一个DNA片段。基于黄颡鱼和瓦氏黄颡鱼的显著遗传差异,设计了一对引物,该引物在黄颡鱼和瓦氏黄颡鱼基因组中分别扩增出1908和1178 bp DNA片段,而且在杂交黄颡鱼中同时扩增出这两个DNA片段。总之,这个新的遗传标记提供了一种稳定、高效识别黄颡鱼及其与瓦氏黄颡鱼杂交种的方法。     

黄颡鱼性别连锁标记Pf62-Y的染色体定位简

正黄颡鱼(Pelteobagrus fulvidraco)隶属鲇形目、科、黄颡属,广泛分布于我国各大水域,是我国重要经济鱼类之一。桂建芳等[1]进行了黄颡鱼银染核型研究,沈俊宝等[2]也报道了黄颡鱼的核型,其核型为2n=52。刘汉勤等[3]利用人工雌核发育等技术开展了全雄黄颡鱼研究,认为黄颡鱼的遗传性别决定类型为XY雄性异配型,Wang,et al.在黄颡鱼中开展了性别连锁的DNA标记分离研究,     

基于基因组重测序的长江上游瓦氏黄颡鱼群体遗传结构

利用基因组重测序的方法获取高通量SNP标记,分析了长江上游三峡大坝-白鹤滩大坝之间8个不同江段(太平溪、巴南、合川、岷江口、宜宾、邵女坪、桧溪、冯家坪)共136尾瓦氏黄颡鱼(Pelteobagrus vachelli)的遗传多样性和遗传分化水平,阐明了长江上游瓦氏黄颡鱼群体遗传结构。结果显示:(1)三峡库区太平溪群体和巴南群体具有较高的SNP(singlenucleotide polymorphism)数量和核苷酸多样性指数,遗传来源丰富,其遗传多样性高于其他群体;上游的岷江口、宜宾、邵女坪和冯家坪群体遗传来源单一。(2)瓦氏黄颡鱼存在3个不同的遗传分支,且不同遗传分支之间存在较大的遗传分化。(3)群体SNP数量和核苷酸多样性指数与河流坡降呈显著负相关,群体遗传分化指数与地理距离和隔离时间无显著相关性。研究结果表明,在三峡大坝-白鹤滩大坝江段,瓦氏黄颡鱼上游群体具有更低的遗传多样性,更易发生遗传漂变作用,在鱼类遗传多样性保护中需要特别关注;瓦氏黄颡鱼存在3种显著的遗传结构,应视为3个不同遗传单元进行种质资源管理。     

中国东部沿海中小型河流鱼类的整体遗传多样性评价——以曹娥江为例

研究将曹娥江作为东部沿海中小型河流代表, 基于线粒体细胞色素b基因(Cyt b)分子标记对其鱼类的整体遗传多样性水平进行了评估。结果表明, 21个种26个群体鱼类Cyt b基因的单倍型多样性指数(h)和核苷酸多样性指数(π)水平分别为0.074—0.987和0.00019—0.00520, 物种间遗传多样性水平差异较大; 比较不同江段鱼类遗传多样性水平发现, 曹娥江鱼类的单倍型多样性指数水平从河口到中下游再到上游逐渐降低(P<0.05)。比较同一物种的遗传多样性水平发现, 曹娥江鱼类的核苷酸多样性指数水平低于长江、珠江等大型河流鱼类的相应指数水平(P<0.05), 提示曹娥江鱼类的整体遗传多样性处于中等偏下水平, 鱼类资源亟需科学的保护和修复。进一步分析人为扰动因素对曹娥江鱼类遗传多样性水平的影响发现, 敏感型鱼类的单倍型多样性指数水平显著低于中等耐受型鱼类(P<0.05); 麦穗鱼(Pseudorasbora parva)、光泽黄颡鱼(Pelteobagrus nitidus)和刺鳅(Mastacembelus aculeatus)3种鱼类的上游镜岭群体单倍型多样性指数和核苷酸多样性指数水平均低于其中游仙岩群体的相应指数水平。结果提示, 水体污染、过度捕捞可能是造成目前曹娥江鱼类遗传多样性水平较低的主要原因。研究结果将为曹娥江乃至东部中小河流的鱼类资源的管理、保护和开发利用提供重要的理论依据。     

三个黄颡鱼群体遗传多样性及亲缘关系的微卫星标记分析

利用微卫星标记技术对3个黄颡鱼群体(W S、TE和QF)的遗传多样性及亲缘关系进行研究。通过筛选的30个引物对3个黄颡鱼群体基因组DNA的扩增,获得了19个有效引物,其中有6个微卫星位点具有多态性,并计算出了3个黄颡鱼群体间的遗传相似系数和遗传距离,TE和QF群体间的遗传相似系数最大(0.8736),遗传距离最小(0.1790);W S和QF群体间的遗传相似系数最小(0.7284),遗传距离最大(0.2768)。同时运用聚类分析(UPGMA)的方法建立了3个黄颡鱼群体的系统发生树。     

黄颡鱼溶酶体酸性脂肪酶基因的cDNA序列、启动子及其转录调控分析

通过分子结构、组织表达及启动子结构功能分析,探讨黄颡鱼(Pelteobagrus fulvidraco)溶酶体酸性脂肪酶(Lysosmal acid lipase,lal)基因的分子特征及转录调控,为lal在鱼类脂质代谢和转录水平的调控提供新的视野.实验采用RT-PCR和RACE克隆lal基因的cDNA全长序列,其长度...     

中间黄颡鱼群体遗传变异与亲缘生物地理

通过分析81尾采自华南西部12条水系的中间黄颡鱼(Pelteobagrus intermedius)mtDNA控制区435 bp的序列,研究其群体遗传变异及亲缘生物地理格局。结果显示,中间黄颡鱼群体间的遗传分化较小,核苷酸变异只有0.54%。12条水系的群体共有7个单倍型,其中一些现已相互隔离的水系中的群体共享同一个单倍型,提示这些水系曾经有非常密切的联系。根据嵌套进化支序分析,中间黄颡鱼可能起源于峒中河、北仑河、防城河所在的广西与越南交界地区,并通过两条途径向华南沿海西部诸独立水系和海南岛扩散,在演化过程中,曾发生片断化事件,长距离建群和持续的分布区扩张。     

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.     

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     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV