蓖麻蚕(Philosamia cynthia ricini)后部丝腺体5SrRNA的核苷酸顺序

本文用凝胶直读法、末端鉴定法以及前标记指纹图谱等几种方法相配合,测定了蓖麻蚕(Philosamia cynthia ricini)后部丝腺体5S rRNA的核苷酸顺序:(pp)pGCCAACGUCCAUACCACGUUGAAAACACCGGUUCUCGUCCGAUCACCGAAGUUAAGCAACGUCGGGCGCGGUCAGUACUUGGAUGGGUGACCGCCUGGGAACACCGCGUGUUGUUGGCUU_(OH)。并比较了蓖麻蚕和家蚕、果蝇5S rRNA结构上的差异,讨论了真核生物5S rRNA结构的保守性。     

蓖麻蚕(Philosamia cynthiaricini)后部丝腺体5SrRNA的核苷酸顺序

本文用凝胶直读法、末端鉴定法以及前标记指纹图谱等几种方法相配合,测定了蓖麻蚕(Philosamia cynthia ricini)后部丝腺体5S rRNA的核苷酸顺序:(pp)pGCCAACGUCCAUACCACGUUGAAAACACCGGUUCUCGUCCGAUCACCGAAGUUAAGCAACGUCGGGCGCGGUCAGUACUUGGAUGGGUGACCGCCUGGGAACACCCGUGUUGUUGGCUU_(OH)。并比较了蓖麻蚕和家蚕、果蝇5S rRNA结构上的差异,讨论了真核生物5S rRNA结构的保守性。     

幼龄小白鼠全脑5SrRNA的全核苷酸序列测定

<正> 5S rRNA是一种稳定的独立小分子,在原核和真核细胞中都牢固地结合在核糖体的大亚基上。它在蛋白质生物合成过程中具有重要作用。微生物、大鼠肝细胞及某些植物细胞5S rRNA的一级结构都已经测定,脑细胞5SrRNA的一级结构尚未见报道。因此,我们对幼龄小鼠全脑5S rRNA的序列进行了分析。我们用辜祥荣等人的方法分离和纯化5S rRNA,5S rRNA3′-末端标记参照Peattie的方法(2)。3′-末端标记5S rRNA的序列分析用化学降解-凝胶直读法及特异RNa8e降解直     

国产植物中蜕皮激素的分离鉴定和对家蚕生理活性的试验

(1)通过107种植物对家蚕的脱皮活性试验,发现唇形科植物野芝麻(Lamium barbatum S.etZ.)是一种新的含蜕皮激素的植物。蜕皮激素收得率是0.029%,熔点239—242℃,TLC Rf 0.5—0.6(黄绿色),并经光谱分析证明为β-蜕皮激素。 (2)从资源丰富的植物土牛膝(Achyranthes bidentata Bl.)中提取了β-蜕皮激素,并进行了蚕用试验与推广应用研究,证明活性及效果稳定,并提出了简易的制作生产方法。 (3)在试验中发现从川牛膝(Cyathula capitata Moquin-Tandon)根提取的Cyasterone给蚕添食大剂量(5微克/头或以上)时蜕变为幼虫-蛹混合型,而添食小剂量(1.5微克/头)蜕变为正常的蛹。     

乌鳢肝5S rRNA的核苷酸序列

应用Peattie,Maxum等化学裂解法,辅以酶解直读法等测定了乌醴(Ophiocephalus argus)肝5S rRNA的核苷酸序列;与已知的虹鳟鱼和纵带泥鳅5S rRNA序列比较,发现它们之间的核苷酸序列具有高度的保守性.利用其一级结构所给出的信息,初步提出二级结构模型.     

乌鳢肝5S rRNA的核苷酸序列

应用Peattie,Maxum等化学裂解法,辅以酶解直读法等测定了乌醴(Ophiocephalus argus)肝5S rRNA的核苷酸序列;与已知的虹鳟鱼和纵带泥鳅5S rRNA序列比较,发现它们之间的核苷酸序列具有高度的保守性.利用其一级结构所给出的信息,初步提出二级结构模型.     

用S1核酸酶作图法测定蓖麻蚕18S rRNA基因的5′端位置

测定基因5′端位置是研究基因转录调控的一个重要前提。本文将蓖麻蚕18S rRNA基因DNA的5′端用~(32)P标记,然后与18S rRNA杂交,再用S1核酸酶水解掉非杂交区的DNA和RNA。分析放射自显影的结果,测出18S rRNA基因5′端的位置。在18S rRNA基因的BglⅡ_2位点向EcoRⅠ,方向延伸约220bp处,从这一结果,可知道蓖麻蚕rRNA基因的转录方向是5′EcoRⅠ_2→BglⅡ_23′。     

家蚕微孢子虫海藻糖酶3的表达、定位及功能

【目的】本研究旨在初步明确家蚕微孢子虫Nosema bombycis海藻糖酶3(NbTre3)的功能,为家蚕Bombyx mori微粒子病的防治提供理论依据和线索。【方法】通过PCR扩增NbTre3,构建原核表达载体pET28a-NbTre3;经IPTG诱导在大肠杆菌Escherichia coli中表达重组蛋白NbTre3,Western blot检测目的蛋白;Ni柱亲和层析法对重组蛋白NbTre3进行纯化,用获得的NbTre3免疫新西兰兔制备多克隆抗体;利用间接免疫荧光技术对成熟家蚕微孢子虫中的NbTre3进行定位;qRT-PCR检测家蚕微孢子虫感染家蚕5龄起蚕后不同时间中肠中NbTre3的转录水平;通过分别注射siRNA-1, siRNA-2和siRNA-3进行RNAi,qRT-PCR检测RNAi后不同时间感染家蚕微孢子虫的家蚕5龄起蚕中肠中NbTre3和16S rRNA的转录水平。【结果】成功纯化并获得重组目的蛋白NbTre3,大小约为34 kD。免疫新西兰兔后,收集血清,纯化获得NbTre3多克隆抗体,经Western blot鉴定正确。间接免疫荧光结果显示NbTre3主要分布在成熟家蚕微孢子虫孢原质中。qRT-PCR结果表明,家蚕微孢子虫感染后6 h时家蚕5龄起蚕中肠中NbTre3的表达量最高;siRNA抑制NbTre3的表达后,家蚕微孢子虫16S rRNA的转录水平没有明显的变化。【结论】结果提示NbTre3可能在家蚕微孢子虫感染初期的发芽过程中发挥重要的作用。     

家蚕中肠组织抗核型多角体病毒病的相关蛋白分析

家蚕中肠上皮是病毒经口侵入遇到的第一个组织。昆虫幼虫抵御杆状病毒的感染,可通过选择性的使感染的中肠上皮细胞发生调亡并在释放病毒粒子进入血淋巴之前使感染的细胞从中肠脱落。为研究家蚕抗核型多角体病毒(Bombyx mori nucleopolyhedrovirus, BmNPV)病的机制,通过对BmNPV高度抗性和高度敏感性的家蚕品系杂交和回交构建了近等基因系。本文对家蚕高抗,敏感及近等基因系5龄起蚕中肠组织的蛋白质表达谱进行了二维电泳 (two-dimensional gel electrophoresis,2-DE) 分析,并利用基质辅助激光解吸电离飞行时间 (matrix-assisted laser desorption/ionization-time of flight, MALDI-TOF) 质谱对差异蛋白进行鉴定。结果发现了5个差异表达的蛋白。推测这些蛋白可能与家蚕中肠对BmNPV的抗性或感性有关。     

樗蚕丝腺5SrRNA的核苷酸顺序

本文用凝胶直读法、末端鉴定法等相配合,测定了樗蚕(Philosamia cynthia)絲腺5SrRNA的核苷酸顺序:AGACAACGUCCAUACCACGUUGAAAACACCGGUUCUCGUCCGAUCACCGAAGUCAAGCAACGUCGGGCGCGGUCAGUACUUGGAUGGGUGACCGCCUGGGAACACCGCGUGCUGUUGGCUU比较了樗蚕、蓖麻蚕、柞蚕、家蚕、果蝇等5SrRNA结构差异,在分子水平上探讨了昆虫的分化。     

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.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

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.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细