海南大绿臭蛙寄生双睾虫属一新种(单殖吸虫纲,多盘虫科)

从海南五指山的大绿臭蛙Ranalivida膀胱内检获多盘科Polysto matidae双睾虫属Diplorchis单殖吸虫1新种,以宿主种名命名为大绿臭蛙双睾虫Diplorchis lividae sp.nov.。新种以肠支侧突明显而区别于蛙双睾虫、拉氏双睾虫和无指盘臭蛙双睾虫;与石林双睾虫的区别是本种的肠支末端进入后吸器;本种中央大钩的形状与杭州双睾虫的大钩基部具深裂的缺刻明显不同;与黑斑蛙双睾虫的区别是本种中央大钩的内突上附有向前延伸的长条形肌腱,另本种卵巢较小、长度与卵相近,而黑斑蛙双睾虫的卵巢长度超过卵长的一倍。本种为海南多盘类单殖吸虫的首次报道。模式标本保存于华南师范大学生命科学学院鱼类寄生虫研究室。     

寄生于杜氏泛树蛙多盘虫属单殖吸虫一新种记述

于云南屏边县杜氏泛树蛙Polypedates dugritei David膀胱内检获单殖吸虫多盘科多盘虫属1新种:屏边多盘吸虫Polystoma pingbianensis sp.nov.,对其形态结构及宿主特异性问题进行了初步研究.据宿主膀胱内寄生的产卵成虫测量形态分类数据和描述鉴定特征.虫体全长平均9.428 mm,后吸器大小平均0.869 mm×0.784 mm,后吸器吸盘的直径平均434.4μm,后吸器上两个中央大钩全长平均403.2μm.朝向外侧肠管无盲突,朝向内侧肠管每侧形成13～14个盲突,有1个或无过腹中线的肠联合,肠管于后端合并向后延伸至后吸器内,不形成盲突.卵巢较小,位于单个睾丸之前,卵巢长平均711.52 μm.卵相对较大,卵长平均306.6μm,卵宽平均164.6μm.     

滇蛙体内寄生单殖吸虫一新种记述

从滇蛙Rana pleuraden Boulenger膀胱内检获单殖吸虫多盘科双睾属1新种,以采集地命名为石林双睾虫Diplorchis shilinensis sp.nov.,新种为目前国内记录双睾属吸虫中体型最小的虫种.描述了新种的形态特征,并与近似种做了比较.新种模式标本保存于云南师范大学生命科学学院动物学教研室.     

两种无尾两栖类的核型与C-带型的比较研究

用骨髓细胞直接制片法,制作染色体玻片标本。无指盘臭蛙(Rana grahami Liu)的核型,2n=26,NF=52,是由二大组染色体组成的,大型染色体5对,小型染色体8对,其中除第3、7、9号染色体为亚中部着丝点外,其余均为中部着丝点染色体。同时还将无指盘臭蛙的核型与国内已报道的几种蛙属种类的核型作了比较,有关对应染色体的相对长度呈现显著性差异。推测臂间倒位、相互易位等染色体重组是存在的。另外还对无指盘臭蛙和昭觉林蛙(R.taponica chaochiaocnsis)做了染色体C-带的观察比较。     

无声囊泛树蛙寄生多盘虫属单殖吸虫一新种

从海南尖峰岭的无声囊泛树蛙Polypedates mutus膀胱内检获多盘虫属Polystoma单殖吸虫1新种,以宿主种名命名为无声囊泛树蛙多盘虫Polystoma mutus sp.nov.。新种以后吸器长相对于虫体全长较小(1.0:7.9～1.0:8.2),锚钩形态,具9根生殖棘等特征而区别于近似种。本种为海南岛多盘虫属单殖吸虫的首次报道。模式标本保存于华南师范大学生命科学学院鱼类寄生虫学研究室。     

基于18S rRNA基因部分序列探讨四种蛙类多盘科吸虫分类地位

分析了寄生于蛙类膀胱的4种多盘虫科Polystomatidae吸虫:石林双睾吸虫Diplorchis shilinensis、锯腿树蛙多盘吸虫Polystoma carvirostris和分别寄生于昭觉林蛙Rana chaochiaoensis、华西雨蛙Hyla a.annectans的2未定种的分类地位,并利用18S rRNA基因部分序列进行了系统发育重建.结果表明:4种多盘科吸虫为多盘虫属Polystoma和双睾虫属Diplorchis的4个分类单元,其中2未定种为多盘虫属未记录种;肠管、生殖系统、后吸器、大钩和生殖棘等为多盘虫属属内种定种的可靠性状.基于18S rRNA基因序列,4种多盘科吸虫呈现以下进化关系:1)寄生于昭觉林蛙和华西雨蛙的多盘虫属2未定种进入欧非混合进化支;2)锯腿树蛙多盘吸虫位于多盘虫属进化支的最基部;3)石林双睾吸虫进入澳洲进化支.     

裂腹鱼指环虫(Monogenea: Dactylogyridae)一新记录种

文章记述了采自新疆伊犁河流域巩乃斯段的新疆裸重唇鱼(Gymnodiptychus dybowskii Kessler, 1874)和斑重唇鱼(Diptychus maculates Steindachner, 1866)鳃部寄生的指环虫属(Dactylogyrus)一新种。通过传统方法及分子生物学方法研究确定了两种宿主寄生的虫体为同一种。该虫体与同宿主寄生的Dactylogyrus driagini(Bychowsky, 1936)和寄生于伊犁裂腹鱼的Dactylogyrus longicopula(Bychowsky, 1936)略为相似, 但在交接器和后吸器形态上有较大差异: 其交接器的支持器部分, 分为上下两部分, 在连接处形成“Y”状结构, D. driagini支持器为完整一体的结构, 而D. longicopula支持器的连接处为卷曲状结构; 后吸器形态: 拟定种与D. driagini, D. longicopula后吸器均由一对中央大钩、7对边缘小钩和两联结片组成, 其中央大钩内、外突不明显, 边缘小钩明显区分钩尖、钩柄和柄轴, 钩尖和钩柄交接处无刺状突起, D. driagini中央大钩内、外突分叶很明显, 边缘小钩各部位区分不明显, 而D. longicopula的中央大钩内、外突分叶非常明显, 内突远远大于外突, 边缘小钩的钩尖和钩柄交接处有刺状突起; 腹联结片粗短, 中部呈峰状隆起, D. longicopula腹联结片两端细长, 中间呈三角状隆起。基于该指环虫18S-ITS1-5.8S rDNA的序列比对分析, 与寄生于属鱼的隐藏指环虫(Dactylogyrus cryptomeres Bychowsky, 1934)的相似性最高, 为92.0%。系统发育树也显示与D. cryptomeres聚为一支, 置信度为100/99(BI/ML), 但综合形态学特征, 宿主生境和宿主特异性等因素, 本种虫体与隐藏指环虫非同一物种。基于形态结构和分子系统发育结果表明, 该指环虫为一新种, 依据宿主特点命名为: 重唇鱼指环虫(Dactylogyrus diptychus n. sp.)。     

玫氏新本尼登虫扫描电镜观察(单殖吸虫纲,分室科)

报道寄生于福建海水养殖鱼类高体蜥的玫氏新本尼登虫(单殖吸虫纲,分室科)的扫描电镜观察。虫体体表无棘,前吸器和后吸器盘状。副甲片、前钩和后钩位于鞘内,副甲片尖状,前钩和后钩弯钩状,边缘小钩呈辐射状排列于后吸器边缘。     

海南岛海水鱼类单殖吸虫研究及宽海盘虫二新种记述

记述了采自海南岛后水湾的眶棘双边鱼Ambassis gymnocephalus Lacépéde鳃上寄生的宽海盘虫2新种.张氏宽海盘虫Euryhaliotrema zhangjianyingi sp nov.以其边缘小钩明显长于两对中央大钩,支持器的套环状特殊结构,两对中央大钩和联结片而不同于属内的已知种;双边鱼宽海盘虫,Euryhaliotrema ambassisi sp.nov.以其交接器的量度,后吸器中央大钩内突基部较宽,外突较小,钩基部较直,钩尖短而不同于相似种和属内已知种.文中量度μm,模式标本保存在海南师范学院生物系.     

寄生于南海鱼类中的单殖吸虫一新种和一新纪录(吸虫纲: 单殖目)

报道了寄生于中国南海的芝麻斑鱼Epinephelus rhyncholepis(Bleeker)(Serranidae)上的香港拟大杯虫Megalocotyloides hongkongensis sp.nov.和寄生于黑鲷Acanthopagrus schlegeli(Bloch)(Sparidae)上的鲷裸盘虫Anoplodiscus spari(Yamaguti,1958)。前者为新种,隶属于分室科Capsalidae (Barid,1853)、轮足亚科Trochpodinae、拟大杯足属Megalocotyoides;后者为中国新纪录,隶属于裸盘虫科Anoplodiscidae(Tagliani,1912)、裸盘虫属Anoplodiscus。香港拟大杯虫Megalocotyloides hongkongensis sp.nov.具分室科、Trochopodinae亚科的形态特征。虫体背腹扁平,呈长椭圆形,体表光滑无棘。前端腹面有一对前吸器,成对吸盘状结构,通过一头冠在前背面联系,有头腺。眼点2对,位于咽前。后吸器盘状,无柄,分成5隔和周边5个小隔室,中央小室缺;后吸盘边上有肌肉缘,周围有精致的圆齿状边缘膜,边缘小钩14个;中央大钩3对,有肌肉纤维支持着,第1对钩大,远端尖,近端钝,分叉,有明显的肌腱通过大钩的分叉牵拉,第2对钩细长,远端有刺钩,第3对钩尖细,远端钩尖略弯曲,3对中央大钩成直线纵向排列,有肌腱牵引。口开于咽中央,咽肌肉质,发达,呈5瓣状。食道不明显或缺。两肠支前端达咽的水平处,末端终止于后吸器前,呈树枝状分布,末端不汇合。睾刃个并列,椭圆形,前端略尖,位于体中部。输出管在中部吻合形成输精管,呈盘曲长管状,阴茎囊椭圆形,靠近卵巢的右上角,阴茎细长,卷曲在阴茎囊内。阴茎复合体包含有肌肉质的阴茎、射精管、前列腺球和前列腺储藏囊。阴茎囊远端与子宫远端联合形成生殖腔,其生殖孔开口于体左侧的前吸器旁。卵巢圆球形,位于睾丸前,输卵管自卵巢发出后,向前略大成卵模,周围有发达的梅氏腺,子宫粗短,开口于生殖腔。卵黄腺呈滤泡状,自咽水平处随肠支,略呈对称状分布至后吸器前,贮卵黄囊位于卵巢前。阴道富肌肉质,管状,近端膨大形成受精囊,远端窄,开口于共同生殖腔下方。卵呈多面体形,虫卵的一端有一根卷曲的长极丝。鲷裸盘中Anoplodiscus spari(Yamaguti,1958)具裸盘虫科Anoplodiscidae、裸盘虫属Anoplodiscus的形态特征。虫体背腹扁平,体前端有一对假吸盘,开口于体外,后吸器盘状,无钩,不分室。具2对眼点,咽发达。食道不明显或缺。单支肠支不对称地呈树枝状分布,末端终止于后吸器前。睾丸单个,圆球形,位于体中部。具贮精囊,阴茎囊长,管状,具有几丁质支持器,卵巢卵圆形,位于睾丸前,具受精囊和阴道,卵黄腺发达,呈大滤泡状,自交接器水平处随肠支,略呈对称状分布至后吸器前。     

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