腹毛目纤毛虫皮膜演化的一种特殊形式—卵圆急纤虫无性二分裂期间的形态发

对海洋纤毛虫卵圆急纤虫无性分裂过程中的形态发生了做了跟踪观察,结果表明,该种的皮膜演化表现了一系列在腹毛目种类中所罕见的特征;１．新老口围带有一临时性汇联为一的阶段;２．左右缘棘毛原基分步出现,即明显的不同步现象;３．大核的改组在细胞分裂开始前即已完成;４．本种后仔虫之棘毛原基的分化既非独立发生又非来自于老结构的反分化,而是紧靠口原基的一侧向外分衍并极可能是孤立地发展而成;５．老的波动膜在形态发生     

悬游双眉虫(原生动物,纤毛门)无性生殖期间的形态发生

应用蛋白银染色技术研究了悬游双眉虫青岛种群无性生殖期间皮层结构和核器的演化过程,其主要特征为:后仔虫口原基独立地出现于紧靠虫体左侧第一根横棘毛的皮层下小龛,其中毛基粒不参与其它棘毛原基的形成;老的口围带发生后半部的局部重建而非整个的由前仔虫简单继承;在前仔虫中,波动膜原基来自老结构的反分化,而在后仔虫中则来自口原基;所有棘毛原基均为独立发生并与老结构没有任何关系;在前仔虫中,口棘毛(即左侧第一根额棘毛)来自于波动膜的反分化,而在后仔虫中则为独立发生;背触毛列于老的结构当中产生,并由最右一列原基演化出3根尾棘毛;两大核片段的改组带从一端向另一端移动 ,并随着两者的融合而消失.文中同时对前人有关该属发生模式的若干存疑问题做了探讨 [动物学报 54(3):517-524,2008].     

急纤虫Tachysoma pellionella无性生殖周期中核器和纤毛器的演化

应用能同时显示纤毛虫的皮膜结构及核器的蛋白银染色方法,研究了急纤虫Tachysoma pellionella的形态及其无性生殖周期中核器和纤毛器的发育演化过程。其中的形态发生过程是:(1)大核改组带出现后,在口围带(AZM)和腹棘毛VC4、VC5之间形成一条细线,于细线中发生许多成群的毛基体,逐渐演变成为后AZM原基区。最终,原基区颗粒组装成一片片整齐排列的小膜,它们构成为新AZM。老AZM也伴随着由基部向前更新,(2)在额棘毛FC5-FC8和腹棘毛VCl-VC3全部瓦解时紧接着产生前、后波动膜原基和新棘毛原基区,并发生波动膜的分化,棘毛的分化、移动和定位过程;(3)左、右缘棘毛原基的发育形式相同,但右缘棘毛原基的发育稍早。在右缘棘毛列中的第2(或第3)根和约第16根棘毛、左缘棘毛列的第1根和约第17根棘毛开始,随老棘毛基部的瓦解,于老棘毛基部位置各产生前、后两部分新缘棘毛原基,左、右每部分原基各占据了约六个老棘毛基部位置后分别朝所在的老棘毛列的外侧、内侧向后伸展开来;(4)在第1—3列背触毛中分别于每列之前、后两部分的中部范围产生前、后第1—3列新原基,每列原基向其两端伸展替代老背触毛列,它们后来成为前、后仔虫的相应的第1—3列新背触毛。接着在前,后各第3列背触毛原基后端发生前、后第4列原基,并稍偏向第3列原     

一种游仆虫棘毛基部纤维的形态及其在形态发生过程中的演化

游仆虫皮层棘毛基部纤维包括纵纤维、前纵纤维和放射纤维:额腹棘毛基部后纵纤维一般长而粗大,前纵纤维次之,放射纤维较细小;横棘毛基部前纵纤维几乎纵贯额腹横棘毛区皮层,而放射纤维较为细小;尾棘毛基部仅与一类更为细小的放射纤维相联系。不同额腹棘毛基部的同种纤维大小、形态不尽一致,各种纤维由棘毛基部区向皮层细胞质多个方向伸展,表现出极性和不对称性。并且额腹横棘毛基部纤维相互交联在一起,导致这一皮层区域形成强大的棘毛基部纤维网络。 游仆虫形态发生中,横棘毛原基向皮层裂口上方伸出一束粗大的纤毛芽时,先后发生模棘毛原基前纵纤维芽、额腹棘毛原基后纵纤维芽,以及这些棘毛原基放射纤维芽。纤维芽的发育顺序是从左列棘毛原基开始,到右侧的棘毛原基。这种纤维物质生长的顺序性,与新棘毛原基的发生和分化是相一致的。并且额腹棘毛基部后纵纤维和横棘毛基部前纵纤维形成中显示出极性和方向性,纤维物质生长伸长的方向与相应的新棘毛迁移方向相反。 老棘毛基部纤维在游仆虫形态发生过程中必然要退化。我们推测,其瓦解过程与细胞分化中老棘毛逐渐失去功能是有联系的。     

小腔游仆虫形态学、个体发育与分子系统学研究

游仆类是纤毛虫中进化最为复杂和高等的一大类群,为了进一步探索和完善游仆类的多样性,本研究利用活体观察、蛋白银和银浸法染色技术对采自青岛小西湖的小腔游仆虫(Euplotes aediculatus)的形态学及细胞发生学进行了详尽的研究,并在完整的形态学及发生学研究基础上,测定了小腔游仆虫的核糖体小亚基基因(SSU r DNA)序列,通过序列比较和分子系统树构建等方法,对小腔游仆虫的系统地位进行了分析。结果表明:本种鉴别特征为9根额腹棘毛,5根横棘毛,2根缘棘毛,2根尾棘毛,8列背触毛,double-eurystomus型银线系。发生学特征包括:(1)后仔虫口原基在表皮下独立发生,前仔虫完全继承老口围带;(2)额–腹–横棘毛原基从左向右按照3:3:3:2:2的模式形成额腹棘毛和横棘毛;(3)前后仔虫最左侧额腹棘毛分别由独立产生的原基形成;(4)缘棘毛原基独立发生;(5)初级背触毛原基来自虫体中部老结构的反分化;(6)前后仔虫尾棘毛分别来自最右侧2列背触毛原基和老背触毛列末端;这些特征显示出游仆虫属个体发生模式的高度保守性。分子系统分析与形态学数据一致,即游仆虫属为单元发生,且小腔游仆虫与艾美游仆虫(Euplotes amieti)、阔口游仆虫(E.eurystomus)和伍氏游仆虫(E.woodruffi)聚在一起。     

卡龙游仆虫无性生殖期间的形态发生学研究：原生动物,纤毛虫

卡龙游仆虫为海洋中自由生纤毛虫,利用银染法对该种二分裂期间的形态发生学进行了初步的研究,其主要过程为：１．伴随大核改组带的出现和ＤＮＡ复制开始,口原基发生于老口围 方皮膜下一龛腔内,后由前至后组装成围口小膜而演化为后ＡＺＭ。老口围带及口侧膜在原位被被前仔虫继承;２．体棘毛场首先出现两组棘毛原基,其随后各自独立演化成９根前、后仔虫的额－腹－横棘毛;３．缘棘毛原基也为独立发生,初为单一,后断裂为二并分     

红色角毛虫的形态学和形态发生过程的研究

观察并描述了上海采集到的红色角毛虫的形态结构和形态发生过程。发现形态发生时虫体分别于前、后两个区域发生前、后两个口围带原基,并且由同一个体分裂而成的前,后两个仔虫内,额、腹、横棘毛和缘棘毛的分化并不完全相同,以至造成两个仔虫上棘毛的数目和缘棘毛的列数有明显差异。根据红色角毛虫的形态结构及其形态发生中的一些不够稳定的特点,推测它可能是一种还处于分化中的腹毛类纤毛虫。     

海洋纤毛虫黄色伪角毛虫无性生殖期间的形态发生

利用蛋白银染色技术研究了海洋纤毛虫———黄色伪角毛虫Pseudokeronopsisflava (Cohn ,186 6 )Wirns berger,Larsen&Uhlig ,1987无性生殖期间的细胞发生学。其主要特征为 :1)前仔虫口原基以独立发生的方式出现并独特地形成于口前庭右侧的皮层深处 ,由其对老口围带进行完全的更新 ;2 )老口器不参与新口器的形成 ,完全被吸收 ;3)前仔虫的额 -腹 -横棘毛原基同样为独立发生 ,老结构可能不参加其随后的发育 ;4 )后仔虫的口原基、波动膜原基及额 -腹 -横棘毛原基均来自最初排列无序的毛基粒发生场 ;5 )背触毛及缘棘毛的更新发生在老的结构中 ,并向前后延伸取代老结构 ;6 )在整个发生过程中 ,无大核融合现象。文中同时对该种所表现的发生学特征及系统学意义做了探讨     

急纤虫Tachysoma pellionella的实验再生

观察急纤虫Tachysoma pellionela切割后的断片的再生过程,发现急纤虫的大核对再生过程具有重要作用。急纤虫在再生过程中它的毛基系的形态发生与所在的皮膜本身相联系,这与其他的许多研究相一致;并且急纤虫的皮膜其老口围带对再生过程中新棘毛原基的棘毛的分化和移动具有抑制作用,它对其远端的抑制作用弱,对近端的强,这种抑制作用随老口围带的小膜的瓦解、吸收和新口围带小膜的改组更新而消失。     

一种游仆虫无性分裂生殖的研究Ⅱ.无性分裂过程中皮层结构的形态发生

应用光学显微镜和扫描电子显微镜,观察到在一种游仆虫无性生殖周期中,新口围带发育时老口围带的更新、新波动膜原基的发生、棘毛原基发生的最早形态和背触毛发生等在其他种游仆虫中未见报道的现象。     

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