长角血若虫发育期20—羟基皮酮含量变化与表皮发生的关系

用高效液相色谱和放射免疫分析对长角血蜱Haemaphysalis longicornis若虫发育期整体蜕皮激素（20－E）含量变化进行了测定,并用扫描电镜对其表皮结构及其发生进行了观察。20－E存在于菲虫整修发育期,饥饿、吸血和饱血后前4天,激素水平低（0.71－1.30ng/头）;饱血后6天明显增加,此时皮溶离开始,蜕皮间隙形成;饱血后7天继续增加;饱血后8天,20－E含量达到高峰（8.70ng/头）,此时若虫开始沉积新的上表皮;高峰后,20－E含量急剧下降,直到蜕皮前保持低水平,此期内沉积新的原表皮,旧表皮被部分吸收,上述结果显示出20－E含量急剧增加及其高峰分别与启动皮层溶离和新的上表皮沉积相吻合,20－E与新的原表皮沉积无关。     

银盾革蜱若虫发育期20-羟基蜕皮酮含量变化规律(英语)

本文利用高效液相色谱(HPLC)对银盾革蜱饥饿、吸血和饱血后若虫整体水平20-羟基蜕皮酮含量变化规律进行了研究.结果表示20-羟基蜕皮酮存在于若虫整个发育期,其含量变化具有两个峰.第一个峰小,出现在吸血期(吸血后5天),含量为2.34ng/只,该峰出现后,若虫快速饱血并从宿主体落下;第二个峰大,出现在蜕化期(饱血后8天),含量为16.17ng/只,此峰可能与上表皮沉积有关.从饱血后第6天至饱血后第8天,20-羟基蜕皮酮含量迅速增加,皮层溶离发生在饱血后7天左右.     

硬蜱中蜕皮激素含量的变化(英语)

为阐明蜕皮激素在硬蜱发育和生殖中的作用,用高效液相色谱法(HPLC)和放射免疫测定法测定了银盾革蜱和长角血蜱中饱血和产卵前后雌虫整体、血淋巴、合神经节及卵巢中蜕皮激素含量的变化.此外,还用HPLC测定了长角血蜱的卵和幼虫中蜕皮激素的含量.结果表明:在饱血前雌虫整体中蜕皮激素含量的变化不大,饱血后迅速增加.血淋巴中的蜕皮激素在饱血后第5天(即产卵前1天)达到高峰,可做为产卵的信号.合神经节中蜕皮激素含量的高峰在饱血后第5天,与血淋巴中高峰出现的时间一致,这与神经分泌细胞的分泌活性变化相吻合.从饱血后第3天起,卵巢中蜕皮激素含量增加很快,直到产卵时止,在长角血蜱的卵中也测到α-蜕皮素,来源于卵巢,随胚胎发育进程其含量逐渐增加.卵产出后第4天到第12天,蜕皮激素的含量增加十几倍.     

长角血蜱幼虫中的蜕皮甾类(英文)

本文用放射免疫分析和高效液相色谱法对长角血蜱幼虫中的蜕皮甾类进行了测定。　蜕皮甾类存在于吸血和饱血幼虫,并且随生理时期而变化。吸血期和饱血后前３天,激素含量低（小于 １４． ３５ｐｇ ＥＥ／只）;饱血后５天迅速上升（２９．８７ｐｇ ＥＥ／只）;饱血后７天达到高峰（５６． ０４ｐｇ ＥＥ／只）;高峰后又下降到低水平（１９．３８ ｐｇＥＥ／只）。高峰期的蜕皮甾类主要为两种成分,２０Ｅ和Ｅ（２０Ｅ∶Ｅ＝３．０７∶１）。２０Ｅ可能是幼虫发育中起主要作用的激素。     

蜕皮激素在银盾革蜱生殖滞育中的作用(英文)

用高效液相色谱法和放射免疫测定法测定了银盾革蜱滞育雌虫的合神经节、血淋巴、卵巢和整体中蜕皮激素的含量,并与正常发育的雌虫做比较。结果表明,滞育雌虫血淋巴和卵巢中蜕皮激素的含量在饱血后前10天与正常发育雌虫基本上相同。饱血10天以后,滞育雌虫蜕皮激素的含量下降,较正常发育雌虫少得多。蜕皮激素的缺乏影响了卵母细胞的发育。为阐明蜕皮激素对滞育雌虫的影响,在不同时间向银盾革蜱滞育雌虫体内注入不同剂量的β-蜕皮素。刚饱血者注入大剂量(1.375和10000ng/蜱)的β-蜕皮素引起雌虫死亡。饱血后20—30天,注入一定剂量(50,70,100ng/蜱)的β-蜕皮素可以促进卵黄形成,并解除了雌虫的生殖滞育,但其所产的卵量明显少于正常发育的雌虫。应用外源蜕皮激素解除硬蜱雌虫的生殖滞育现象尚属首次报道。     

双斑恩蚜小蜂寄生对烟粉虱体内保幼激素和20-羟基蜕皮酮含量的影响

用反相高效液相色谱法（RP-HPLC）测定了烟粉虱Bemisia tabaci体内保幼激素和20-羟基蜕皮酮的滴度。结果显示,被双斑恩蚜小蜂Encarsia bimaculata寄生的烟粉虱高龄若虫体内的保幼激素滴度显著高于（P<0.05）对照即未被寄生的高龄若虫,20-羟基蜕皮酮（20-E）滴度显著低于（P<0.05）对照,与未被寄生的低龄若虫滴度差异不显著,说明双斑恩蚜小蜂寄生后可以将烟粉虱高龄若虫的激素含量保持在低龄若虫的水平,从而调节烟粉虱高龄若虫的生长发育。烟粉虱伪蛹和成虫与对照体内保幼激素含量,烟粉虱伪蛹与对照之间20-E含量差异均不显著（P>0.05）。     

东方粘虫末龄幼虫血淋巴蜕皮甾类滴度的变化及促前胸腺激素对前胸腺的活化作用

东方粘虫六龄幼虫血淋巴蜕皮甾类滴度,在幼虫的取食生长期一直处在很低的水平(<6pg/μl血淋巴),其后于徘徊期的前一天开始升高,至预蛹期形成唯一的1个高峰(～450pg/μl血淋巴)。前胸腺离体培养的结果表明,前胸腺分泌活力与血淋巴蜕皮甾类滴度的动态呈基本平行的趋势,只是较后者超前了约24小时。促前胸腺激素粗提物能直接活化离体前胸分泌蜕皮甾类。粘虫六龄2日龄(LVI_2)幼虫的前胸腺已能被促前胸腺激素活化,说明此时的前胸腺对促前胸腺激素已具感受性。     

棉铃虫蛹期血淋巴的蜕皮甾类

目前为止仅在少数几种昆虫中研究过蛹期的蜕皮激素。关于蜕皮甾类的性质分析,结果也颇不一致。本文采用放射免疫分析、薄层层析、高压液相色谱及质谱对棉铃虫Heliothis armigera蛹血淋巴内的蜕皮激素进行了研究。结果如下:1.物理-化学方法证明蛹血淋巴内存在二种蜕皮甾类:蜕皮酮和20-羟基蜕皮酮。2.蛹期蜕皮甾类滴度呈一宽峰,高峰出现在化蛹后的第5天(3435ng/ml)。3.在高峰时,蜕皮酮与20-羟基蜕皮酮的比例为1:3.57,说明20-羟基蜕皮酮是主要的蜕皮甾类。4.比较雌雄两性蛹的蜕皮甾类滴度,未见明显差异。研究表明在棉铃虫中影响成虫发育的主要激素是20-羟基蜕皮酮而不是蜕皮酮。     

新型非甾醇蜕皮激素类杀虫剂对棉铃虫幼虫蜕皮的影响

用透射电镜技术研究了新型非甾醇蜕皮激素类杀虫剂W200013对棉铃虫4龄幼虫蜕皮的影响。结果表明W200013使棉铃虫产生早熟、致死的蜕皮。中毒试虫6 h表现出内表皮层沉积加快,皮细胞中粗面型内质网大量增加,糖原颗粒减少;12 h蜕皮间隙开始形成,细胞质凝集;24 h新、旧表皮同时存在,皮细胞空泡化严重;36 h新上表皮覆盖于仅沉积几层的新原表皮上,旧表皮仍然保持,皮细胞呈恶化、降解状态,宏观上虫体不表现出蜕皮行为而死亡。而且比较研究可见W200013在中毒症状、生物测定结果、超微结构水平与RH-5992具有相似的作用。     

飞蝗Knickkopf家族基因表达对蜕皮激素的响应

【目的】研究飞蝗LocustamigratoriaKnickkopf(Knk)家族基因mRNA表达对蜕皮激素（20-hydroxyecdysone,20E）的响应情况,丰富飞蝗Knk家族基因功能研究,为飞蝗表皮发育相关基因的转录调控研究奠定基础。【方法】采用RT-qPCR方法,对LmKnk家族4个基因在飞蝗不同发育天数（5龄若虫第1天到成虫第3天）的表皮中的表达特性进行分析;向飞蝗体腔注射20E,分析LmKnk家族4个基因表达的变化情况;采用RNAi技术干扰20E受体基因LmEcR,分析LmKnk家族基因的表达变化情况。【结果】通过RT-qPCR检测,发现LmKnk在飞蝗5龄第1天至成虫第3天不同发育天数的表皮中均衡表达,而LmKnk2,LmKnk3-FL及LmKnk3-5'基因均在蜕皮前表达量逐渐升高,蜕皮后迅速降低。向飞蝗体腔注射20E后,发现飞蝗Knickkopf家族4个基因对20E均有应答,但响应时间点有差异,LmKnk和LmKnk2的表达量分别在注射20E 3 h和6 h后开始升高,而LmKnk3-FL和LmKnk3-5'的表达量在注射20E12h后开始上升。飞蝗5龄第1天若虫注射ds LmEcR后,发现Knickkopf家族4个基因表达均下调。【结论】飞蝗Knickkopf家族基因的表达受20E调控,是20E的下游应答基因。     

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.     

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.