八种青藓科植物蒴齿及孢子的超微形态研究

利用扫描电镜观察了八种青藓科植物孢子及蒴齿的形态,青藓科植物的孢子纹饰多以芽孢状和瘤状突起为主,孢子的大小、外壁纹饰的差异显示了不同种之间的遗传分化及系统演化。青藓属外齿层腹面中部分为四种类型:光滑无疣、颗粒状疣、短刺状小疣、棒状和芽孢状疣,外齿层中上部的特征属与属之间存在差异,该研究可为分类鉴定提供一定的依据。     

真藓属（Bryum Hedw.）蒴齿形态特征及其分类学意义

通过光学显微镜和扫描电子显微镜观察了中国产真藓属（Bryum Hedw.）12种植物蒴齿的形态特征。结果显示,根据真藓属齿片的曲向可以分为近直立、齿片伸入齿条间和齿片向外反曲等3种类型。根据齿毛的有无,也可分为3个类群。同时利用STATISTICA 6.0统计软件对12种真藓属植物进行聚类分析及主成分分析。研究结果显示,齿片的曲向类型、齿毛是否发育等形态特征可作为真藓属植物种间的分类依据,为藓类植物蒴齿形态特征与分类和系统进化关系的研究提供了新的资料。     

烟杆藓属及烟杆藓在中国的新记录

从形态学而论,烟杆藓属(Buxbaumia Hedw.)在苔藓植物中是一个独特的类型。该文简要介绍了烟杆藓属的历史和该属在中国的研究状况,以及该属的模式种烟杆藓首次在中国的发现。对烟杆藓在新疆的着生生境及群落状况做了详细介绍, 还就扫描电子显微镜观察烟杆藓的孢蒴、蒴齿和孢子形态、中国烟杆藓属分种检索表及属的系统关系进行观察和探讨。     

拟纤枝真藓(Bryum petelotii)的地理新分布与分类地位探讨

报道了中国大陆新记录种——拟纤枝真藓(Bryum petelotii Thér.et Henr.)在贵州、云南的分布;描述了本种的形态特征和地理分布,并讨论了本种与相近种真藓(Bryum argenteum Hedw.)和纤枝短月藓［Brachymenium exile(Doz.et Molk.) Bosch et Lac.］的关系;基于文献和相关标本的研究,阐述并讨论了Ochi H.和B.C.Tan等关于该种分类地位的观点,并赞同将拟纤枝真藓置于真藓属(Bryum Hedw.)的观点。     

烟杆藓属及烟杆藓在中国的新记录（英文）

从形态学而论,烟杆藓属(Buxbaumia Hedw.)在苔藓植物中是一个独特的类型。该文简要介绍了烟杆藓属的历史和该属在中国的研究状况,以及该属的模式种烟杆藓首次在中国的发现。对烟杆藓在新疆的着生生境及群落状况做了详细介绍,还就扫描电子显微镜观察烟杆藓的孢蒴、蒴齿和孢子形态、中国烟杆藓属分种检索表及属的系统关系进行观察和探讨。     

中国东北六种藓类植物的细胞学观察

本文对我国东北产6种藓类的孢子母细胞减数分裂中期I的染色体数进行了报道。结果如下： 羽枝青藓Brachythecium plumosum （Hedw．)B．S．G．,n=15;钝叶绢藓Entodon obtusatus(Mitt) Jaeg．,n=11;东亚绢藓E．okamurae Mitt,n=11;丛本藓Anoctangium aestivum(Hedw．)Mitt．, n＝13;真藓Bryum argenteum Hedw．,n=10;尖叶美喙藓Eurhynchium eustegium(Besch．)Dix.,n=20+2m,其中前三种为首次报道。     

新疆曲尾藓属10种植物蒴齿和孢子的形态观察

该研究通过光学显微镜(LM)和扫描电镜(SEM)观察了曲尾藓属(Dicranum Hedw.)10种植物的蒴齿和孢子的形态特征。结果表明:(1)曲尾藓属10种植物的孢蒴均为圆柱形。(2)孢子球形、近球形、椭圆形或三角状卵形,颜色为黄色、棕色或黄褐色;近极面向内凹,纹饰为疣状、颗粒状或芽孢状。(3)曲尾藓属10种植物的蒴齿多为披针形,但也有阔披针形,颜色为杏黄色、深红色、褐黄色或红褐色;纹饰为条状或疣状,具穿孔成网状结构,一些种无穿孔成平滑结构,表面具细疣。该研究结果为曲尾藓属属下类群划分提供了分类依据,并为苔藓植物系统分类、演化研究提供基础资料。     

大帽藓(Encalypta ciliata Hedw.)原丝体发育特征的实验研究

在人工培养大帽藓(Encalypta ciliata Hedw．)孢子的基础上,对其孢子萌发、原丝体发育及配子体发生的全过程进行行了观察、描绘和照相。实验结果表明：在大帽藓的原丝体系统中主要包括两种成分,即：粗短的丝状绿丝体和细长的柳枝状轴丝体。丝状绿丝体一般由4～6个短粗柱状细胞组成,而轴丝体则是由多数细长柱形细胞构成,其上间隔分布有2～5个细胞组成的棒状体,初生假根有或者无。同时,还对大帽藓原丝体发育的特征进行了分析和讨论,初步确定大帽藓孢子萌发属于新的孢子萌发类型——大帽藓型(Encalypta-type)。     

大帽藓(Encalypta ciliata Hedw.)原丝体发育特征的实验研究

在人工培养大帽藓(Encalypta ciliata Hedw.)孢子的基础上,对其孢子萌发、原丝体发育及配子体发生的全过程进行了观察、描绘和照相。实验结果表明:在大帽藓的原丝体系统中主要包括两种成分,即:粗短的丝状绿丝体和细长的柳枝状轴丝体。丝状绿丝体一般由4～6个短粗柱状细胞组成;而轴丝体则是由多数细长柱形细胞构成,其上间隔分布有2～5个细胞组成的棒状体,初生假根有或者无。同时,还对大帽藓原丝体发育的特征进行了分析和讨论,初步确定大帽藓孢子萌发属于新的孢子萌发类型——大帽藓型(Encalypta-type)。     

小立碗藓属在中国的记录

本文作者在湖南张家界采得小立碗藓属植物,经扫描电镜显示,其孢子具多数柱状疣的特征与小立碗藓加利福尼亚亚种相一致,可确定它为P．patens(Hedw．)B．S．G．subsp．californica(Crum et Anderson)Tan。此为小立碗藓属植物在我国的首次记录。     

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.