腹毛目纤毛虫鬃棘尾虫纤毛器基部微管的荧光标记

腹毛目纤毛虫鬃棘尾虫的纤毛器微管骨架由口围带、波动膜、额腹横尾棘毛、左右缘棘毛和背触毛等纤毛器微管和纤毛器基部附属微管等组成,其中口围带基部含小膜托架、小膜后微管、小膜托架微管及小膜托架间的倒"V"形微管连接;波动膜基部形成微管骨架网;额腹横棘毛和左、右缘棘毛基部含前纵微管束、后纵微管束和横微管束,但不同位置的棘毛基部微管发达程度不一样;背触毛基部以纤毛基体为中心向前、后皮层发出前纵微管和后纵微管,形成背皮层微管网.     

华美游仆虫细胞微管胞器的直接荧光和免疫荧光标记

应用直接荧光和免疫荧光标记显示,腹毛目纤毛虫华美游仆虫(Euplotes elegans)细胞微管胞器由口围带、波动膜、额腹横棘毛、缘棘毛、尾棘毛、背触毛等纤毛器微管以及纤毛器基部附属微管和非纤毛区皮层微管骨架组成.其中,口围带基部含有小膜托架、小膜附属微管,波动膜基部含有波动膜托架,额腹横棘毛基部含有前纵微管束、后纵微管束、横微管束或放射微管柬,左缘棘毛和尾棘毛基部微管束分化不明显,背纤毛基部含有攻瑰花状的基体周围骨架,这些微管结构与细胞背腹面皮层纵微管与横微管网一起组织成该类纤毛虫的主要皮层细胞骨架.结果表明,游仆虫皮层细胞骨架是以微管为主要成分构建而成的,并且其棘毛基部微管的组成具有与其他类纤毛虫不同的特征;游仆虫间期细胞及形态发生时期纤毛基体或纤毛原基中存在中心蛋白,其可能与纤毛基体结构的维持及基体发生过程中微管的组装有关.     

用非离子去垢剂抽提获得的小游仆虫皮层细胞骨架的构形

由扫描电镜术显示,应用非离子去垢剂抽提获得的小游仆虫(Euplotes grocilis)皮层细胞骨架是由非纤毛区皮层骨架、纤毛器骨架及其附属纤维等构成的三维结构网架。各类细胞骨架以纤维物质为基本成分组成纤维网、纤维层、纤维束和纤维薄片等不同形态单元。其中：非纤毛区皮层骨架以表面纤维网和表膜下纤维层为形态单元位于细胞的外周层;纤毛器骨架中的口围带骨架、口侧膜骨架、额腹横棘毛骨架按各自的分布图式在皮层内定位,成为主要的皮层骨架结构。尽管这些纤毛器骨架显示不同的形态,但却具有相同的建构特征,即都是由纤毛器的毛基体、纤毛器托架和骨架附属纤维相互联系镶嵌在一起形成的相对独立的结构单元。分析推测,游仆虫皮层表面纤维网使细胞表面形成区域化结构,它也可能与细胞表面各部分的联系及其细胞与环境的相互作用有关;纤毛器骨架中各个纤毛器的毛基体复合结构可能对纤毛器托架和骨架附属纤维等起到微管组织中心的作用。     

腹毛目纤毛虫大尾柱虫腹皮层纤毛器基部微管的荧光标记

应用荧光紫杉醇直接荧光标记,显示腹毛目纤毛虫大尾柱虫Urostyla grandis腹皮层纤毛器微管胞器由口围带、波动膜、额腹横棘毛和左、右缘棘毛等纤毛器微管、纤毛器基部附属微管等组成.其中,口围带小膜托架及其相联系的肋壁微管和波动膜基体托架,额棘毛基部前纵微管束、后纵微管束及横棘毛基部前纵微管束,中腹棘毛及左、右缘棘毛基部前纵微管束、后纵微管束和横微管束,是该纤毛虫皮层纤毛器基部的主要附属微管.据结果推测,尽管腹毛目纤毛虫的纤毛器基部微管具有相同的结构成分,但其结构的组成、分化特征、定位和定向、发达程度等均有差异.所得结果为进一步说明纤毛虫细胞皮层纤毛器的形态及其微管建构的多样性提供了新的证据资料.     

阔口尖毛虫纤毛器微管的激光共聚焦显微镜观察

应用激光扫描共聚焦显微术显示经荧光紫杉醇标记的阔口尖毛虫(Oxytricha platystoma)口围带、波动膜、额腹横棘毛、左右缘棘毛等纤毛器的微管类细胞骨架.其口围带基部含小膜托架、托架间连接微管和小膜基部微管束,波动膜基部含发达的微管骨架网,口围带和波动膜后端的汇合处含有口底托架及口后微管束,额腹横棘毛和左、右...     

魏氏拟尾柱虫腹皮层纤毛器微管胞器的形态及形态发生

应用荧光紫杉醇直接荧光标记和抗α-微管蛋白抗体免疫荧光标记显示,魏氏拟尾柱虫(Paraurostyla weissei)腹面皮层纤毛器微管胞器由口围带、波动膜、额腹横棘毛和左右缘棘毛等纤毛器微管、纤毛器基部附属微管等组成。其中口围带基部微管包括小膜托架、小膜附属微管;额腹横棘毛和左右缘棘毛基部附属微管包括前纵微管束、后纵微管束和横微管束,它们由各自的纤毛器基部向皮层细胞质不同方向发射,形成腹皮层表面下微管网。结果表明,魏氏拟尾柱虫的纤毛器骨架、纤毛器附属结构也是一类以微管蛋白为基本成分的微管胞器,其中缘棘毛基部附属微管具有不同于其他纤毛虫(例如棘尾虫)中所观察到的同种微管胞器的建构特征。形态发生中,前仔虫口围带在老结构位置形成,其结构建成与部分老口围带的更新有关;老缘棘毛的结构物质对新的左、右缘棘毛的发生可能具有定位作用及物质贡献,但此后新的左、右缘棘毛列分别在老缘棘毛的右侧形成,而并非是在老缘棘毛位置分化的。在有些细胞中,新的左缘棘毛左侧另有一列棘毛,这可能是形态发生中老的左缘棘毛退化不完全产生的。     

草丛土毛虫皮层纤毛器的微管胞器研究

本文应用FLUTAX直接荧光标记和抗α-微管蛋白抗体免疫荧光标记．显示了土壤纤毛虫草丛土毛虫（Territricha stramenticola）的皮层纤毛器微管胞器．其中纤毛器基部微管按口围带、波动膜、额腹横棘毛、左右缘棘毛、背触毛等纤毛器图式分布和定位,口围带和波动膜基部含小膜微管托架、小膜附属微管和波动膜微管骨架网;额腹横棘毛基部含前纵微管束、后纵微管束和横微管束：左、右缘棘毛基部含前纵微管束、后纵微管束、横微管束及后微管芽;背触毛基部含前纵微管束、后纵微管柬。横棘毛基部含有较发达的横微管束,缘棘毛基部含后微管芽及其横微管束的定位可能具有本种纤毛虫细胞的特异性。纤毛器微管胞器在细胞表膜下分化形成的基部微管及其微管层使细胞的运动纤毛器与强固的微管骨架结构网相联系．其微管胞器的建构可能是细胞对土壤生存环境的一种适应．是细胞运动胞器的功能活动与环境相互作用的结果。形态发生中,老口围带微管是逐步进行更新的：老棘毛微管胞器对新结构的发生和形成具有定位和物质贡献的作用．并且老结构在新结构分化和成熟期间也经历了行使相应的生理功能及逐渐退化和失去功能的过程．     

新伪尾柱虫腹皮层纤毛器微管胞器的形态和形态发生

应用荧光紫杉醇直接荧光标记法显示,腹毛目纤毛虫新伪尾柱虫(Pseudourostyla nova)腹皮层纤毛器微管胞器由口围带、波动膜、额腹横棘毛和左右缘棘毛等纤毛器微管及纤毛器基部附属微管组成.口围带基部含小膜托架及与托架相联系的肋壁微管,其中领部小膜托架间由"Λ"形微管相联接;额腹横棘毛基部含前纵微管束、后纵微管束、横微管束和周围微管束,其微管在不同棘毛基部的发达程度不一;缘棘毛基部含前纵微管束、后纵微管束.同时,对新伪尾柱虫纤毛器微管胞器的形态发生和生理改组过程进行了详细的追踪研究,并对细胞皮层的额腹棘毛定位及组成特征进行了补充报道.此外,发现形态发生末期新纤毛器微管形成时,残存部分老额棘毛、横棘毛和缘棘毛,此后老结构逐渐被吸收.结果表明,新伪尾柱虫的纤毛器基部微管具有其种的特异性,新纤毛器微管分化过程中老结构可能具有定位和物质贡献作用.     

冠突伪尾柱虫的腹皮层纤毛器微管胞器及其形态发生

应用荧光紫杉醇直接荧光标记和抗α-微管蛋白抗体免疫荧光标记方法,显示冠突伪尾柱虫腹皮层纤毛器微管胞器由口围带、波动膜、额腹横棘毛和左右缘棘毛等纤毛器微管、纤毛器基部附属微管等组成。口围带基部含小膜托架及与托架相联系的肋壁微管,其中领部小膜托架间由"∧"形微管相联接;额腹横棘毛基部含前纵微管束、后纵微管束、横微管束和周围微管束,其微管在不同棘毛基部的发达程度不一,其中两列中腹棘毛基部微管紧密联系成一条粗绳索样结构,且左、右中腹棘毛基部的横微管束定向相反;左、右缘棘毛基部含前纵微管束、后纵微管束和横微管束,其中横微管束不发达。与目前已知的腹毛目纤毛虫例如贻贝棘尾虫、魏氏拟尾柱虫的纤毛器基部微管相比较,冠突伪尾柱虫腹皮层纤毛器基部微管除具有腹毛目纤毛虫纤毛器基部微管的基本特征外,也具有一些特殊的组成模式。皮层纤毛器微管形态发生中,前仔虫口围带并非全部是由老口围带更新而来的,其老口围带只有翻领部发生更新,且翻领部与领部接续处有一小段老的翻领部小膜保留,领部的小膜保留,结果其领部小膜、接续处保留的小膜与更新的翻领部小膜三部分共同组成前仔虫的新口围带。在后仔虫口原基发生的位置,其邻近的老横棘毛没有变化,此时老的横棘毛或许能起到"参照点"或定位作用;各类纤毛器发生、分化过程中,处于非原基区的老额棘毛、横棘毛及左右缘棘毛在较长时间内均未见明显的变化。它们可能是在新结构形成时仍然起到运动作用继而逐渐失去功能而退化瓦解的。     

原生动物贻贝棘尾虫微管胞器的荧光标记与显示

采用FLUTAX直接荧光标记和抗α微管蛋白抗体的间接免疫荧光标记显示,原生动物贻贝棘尾虫(Stylonychia mytilus)细胞微管胞器由口围带、波动膜、额腹横棘毛、左右缘棘毛、背纤毛等纤毛器微管骨架、纤毛器基部附属微管和其他皮层微管骨架组成。纤毛器微管骨架和基部附属微管按皮层纤毛模式定位;皮层左、右侧微管带和领肋壁微管等其他皮层微管构成细胞特定位置的皮层微管骨架,并可能为具有背腹分化的腹毛目纤毛虫所特有,对维持细胞背腹面的形态、支持附近纤毛器(如左、右缘棘毛)的运动起作用。本文较完整地阐述了其细胞骨架的三维构形,对于深入了解纤毛虫细胞微管骨架的结构和分布特征,进一步揭示微管类胞器的功能是有意义的。     

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.     

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.     

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     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.