携带肺吸虫尾蚴的淡水螺类一新属二新种记述

近年来我国肺吸虫病的防治工作深入开展,引起人们对于寄生虫病流行区的某些淡水螺类,特别是对一些微小螺类的注意。福建及湖南两省1976年分别进行肺吸虫病调查时所采获的,并已查到肺吸虫尾蚴的螺类,经我们分析鉴定为二新种,隶属于觿螺科拟小豆螺属(新属)及小豆螺属。兹分别叙述如下。     

中国小豆螺属一新种描述

小豆螺是一种微小的淡水螺类,属于觿螺科(Hydrobiidae),小豆螺属(Bythinella)。该属首次报道于欧洲(Ehrmann,1933)5,后曾在日本发现6,7,10,12,近年又在我国湖南(刘月英等,1979)、湖北(康在彬,1983)等省发现。其中有些种类是并殖吸虫(Paragonimus)的第一中间宿主2-4,8,9,因此,引起了寄生虫学家和医学贝类学家的极大关注。本文报告小豆螺属一新种,定名为李氏小豆螺(Bythinella lii,sp.nov.)。       

石门拟小豆螺——携带肺吸虫尾蚴的湖南淡水螺类一新种

湖南省石门县卫生防疫站于1979年10月在湘北石门县肺吸虫病疫区现场查获体内有短尾肺吸虫尾蚴寄生的小螺类。经分析鉴定,系隶属于觽螺科(Hydrobiidae)拟小豆螺属(Pseudobythinella)的新种,兹描述于下。     

中国小豆螺属一新种描述

小豆螺是一种微小的淡水螺类,属于 螺科(Hydrobiidae),小豆螺属(Bythinella)。该属首次报道于欧洲(Ehrmann,1933),后曾在日本发现,近年又在我国湖南(刘月英等,1979)、湖北(康在彬,1983)等省发现。其中有些种类是并殖吸虫(Paragonimus)的第一中间宿主,因此,引起了寄生虫学家和医学贝类学家的极大关注。     

中国拟钉螺属两新种记述(中腹足目,盖口螺科)

报道了采自福建省建瓯市和华安县的拟钉螺属Tricula2新种,分别命名为建瓯拟钉螺T.jianouensis sp.nov.和华安拟钉螺T.huaanensis sp.nov.,并与近似种福建拟钉螺比较。上述两种螺类,均为斯氏并殖吸虫第1中间宿主。     

中国光螺属一新种记述(肺螺亚纲,柄眼目,拟阿勇蛞蝓科)

在整理陕西师范大学生命科学学院许升全先生赠送的陆生贝类标本时,经鉴定发现1新种,即太白山光螺Xesta taibaishanensis sp.nov..隶属腹足纲、肺螺亚纲、柄眼目、拟阿勇蛞蝓科、光螺属.对新种形态特征、栖息环境进行了记述,并与近似种进行了比较和讨论.     

拟钉螺属一新种——宁海拟钉螺

浙江省宁海县卫生防疫站于1983年8月在进行肺吸虫病调查时,发现一种小螺,经鉴定为拟钉螺属一新种,现描述如下: 宁海拟钉螺,新种Tricula ninghaiensis,sp.nov.(图1—3) 贝壳小型,外形呈尖圆锥形。有6个螺层,各螺层缓慢均匀增长;壳顶钝圆,壳顶及其     

基于SSR标记分析小豆及其近缘植物的遗传关系

本研究利用87对SSR引物分析了80份栽培小豆(Vigna angularis)、22份野生小豆(V.angularis var.nipponensis)以及10份豇豆属(共7个种)近缘植物,旨在比较豇豆属不同种的遗传多样性,并分析种间的遗传关系.结果显示87对SSR引物在112份小豆及其近缘植物资源中共检测到667个等位变异.其中有75个、71个和82个SSR位点分别在栽培小豆、野生小豆和近缘植物中表现为多态.随机抽样分析发现,平均每SSR位点检测到的等位变异数目为近缘植物>野生小豆>栽培小豆,与多态信息含量(PIC)值一致,说明近缘植物及野生小豆中蕴含着丰富的遗传变异,是栽培小豆育种的重要基因来源.聚类分析显示,栽培小豆、野生小豆和近缘植物间的遗传分化比较明显,分别聚为三大类,其中栽培小豆的遗传背景与其生态环境相对应;近缘植物又可以分为三个亚类,亚类间的遗传距离与其亲缘关系相对应.本研究结果也说明利用SSR标记辅助豇豆属的种间分类是可行的.     

四川拟锥螺属一新种记述(腹足纲:肺螺亚纲:柄眼目:巴蜗牛科)

记述采自四川南充拟锥螺属蜗牛1新种,南充拟锥螺Pseudobuliminus (Pseudobuliminus)nanchongensis sp.nov。新种贝壳与Pseudobuliminus(Pseudobuliminus)piligerus(Moellendorff,1899)相近,但前者螺壳细长,矢囊相对小,受精囊管细长,正模,成螺,四川省南充新建乡,1964-05-20;副模,15只成螺,同正模,模式标本保存于中国科学院动物研究所。     

不同品种小豆光合作用和生长发育对弱光的响应

为确定小豆作为林果行间套种作物的适宜性,通过田间试验和盆栽试验,测定全光和弱光处理(全光的48%)下3个小豆品种(阜南绿小豆、早熟黑小豆、晚熟黑小豆)在初花期的叶片光合特征参数、光合色素含量和RuBPCase活性,研究小豆生长发育对弱光的响应.结果表明: 弱光使3个品种小豆叶片的最大净光合速率、光饱和点、光补偿点等光合参数不同程度地向耐荫的方向变化,净光合速率、水分利用效率和RuBPCase活性也显著下降;遮阴后,阜南绿小豆的叶绿素a和b含量显著增加,Chl a/b和类胡萝卜素含量显著降低,其他小豆的叶绿素和类胡萝卜素含量无明显变化;弱光使3个品种小豆的生物量和干物质积累效率降低,根冠比降低,根瘤量减少,叶片数和叶面积指数减小;弱光胁迫下,阜南绿小豆提前开花、提前成熟,早熟黑小豆推迟开花、延迟成熟,而晚熟黑小豆只开花不结实.从遮阴后小豆的光合特性变化和生长发育差异等方面综合考虑,3个小豆品种的耐阴能力大小为:阜南绿小豆>早熟黑小豆>晚熟黑小豆.     

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.