珍珠菜属3种植物的核型分析

采用常规压片法,对珍珠菜属(Lysimachia L.)3种植物的核型进行了研究。结果表明,长蕊珍珠菜的核型为2n=2x=24=12m 10sm 2st,显苞过路黄的核型为2n=2x=24=4m 6sm 6st 8t,均属首次报道。过路黄的核型为2n=2x=24=2m 2sm 4st 16t,与前人报道的有所不同。还对已报道的珍珠菜属的核型类型与不对称系数进行了比较。     

珍珠菜属八种植物的花粉形态研究

利用扫描电子显微镜,首次对珍珠菜属(LysimachiaL.)8种植物的花粉形态进行了观察研究,报道了花粉形态特征,探讨了花粉形态特征在分类学上的意义。结果表明:该属花粉粒大小和外壁雕纹可作为分种的依据。     

珍珠菜属植物种皮微形态特征及其系统学意义

利用光学显微镜和扫描电镜对11种珍珠菜属植物种皮微形态特征进行了研究。根据种皮微形态特征,可以明显的划分为两种类型,即黑腺珍珠菜型和金爪儿型。珍珠菜亚属的7种植物均属于黑腺珍珠菜型,黄连花亚属的4种植物均属于金爪儿型。种皮微形态特征支持以雄蕊群的构造为主要依据的属下分类系统,在亚属级水平具有重要的分类学意义。     

5种珍珠菜属植物的核型分析

对 5种珍珠菜属 (LysimachiaL .)植物的核型进行了研究 ,其中巴东过路黄 2n =2x =2 4 =6m 4sm 6st 8t、光叶巴东过路黄 2n =2x =2 4 =6m 4sm 6st 8t、临时救 2n =2x =2 4=2m 4sm 4st 14t的核型属首次报道。过路黄 2n =2x =2 4 =2m 4sm 6st 12t和星宿菜2n =2x =2 4 =2 0m 4sm与前人报道的一致。本文还对该属已报道的 17种植物的核型资料进行了总结和比较分析 ,对珍珠菜属植物的核型进化方向作了初步推测。另外对一存疑过路黄(2n =2x =2 4 =2m 6sm 4st 12t)与其近缘种的核型进行了比较研究。     

珍珠菜属四种植物的核型分析

对珍珠菜属4种植物的核型进行了研究。结果表明,叶头过路黄(Lysimachia phyllocephala Hand.-Mazz.)的核型为:2n=2x=24=2m 6sm 2st 14t,茂汶过路黄(L. stellarioidesHand.-Mazz.)的核型为:2n=2x=24=4m 2sm 18t,均属首次报道。矮桃(L. clethroidesDuby)的核型为:2n=2x=24=16m 8sm(1SAT),腺药珍珠菜(L. stenosepala Hemsl.)的核型为:2n=2x=24=10m 12sm 2st,与前人报道的有所不同。还对该属已报道的23种植物的核型进行了比较。     

两种过路黄的核型研究

对国产报春花科珍珠菜属植物过路黄和疏节过路黄的核型进行了首次报道。过路黄染色体数目为２ｎ＝２４,核型公式为２ｎ＝２４＝２ｍ＋４ｓｍ＋６ｓｔ＋１２ｔ,核型类型“３Ａ”;疏节过路黄染色体数目为２ｎ＝２２,核型公式为２ｎ＝２２＝４ｍ＋６ｓｍ＋１０ｔ,核型类型“３Ａ”。     

珍珠菜rDNA ITS序列扩增及分析

以贵州境内珍珠菜属植物为材料,对其rDNA转录间隔区(ITS)序列进行PCR扩增和序列测定。实验共得到7个种的ITS序列,它们分别是:过路黄(Lysi machia christinae,GenBank登录号FJ362382),矮桃(L.cle-throides,GenBank登录号FJ362383),叶头过路黄(L.phyllocephala,GenBank登录号FJ362386),临时救(L.con-gestiflora,GenBank登录号FJ362387),显苞过路黄(L.rubiginosa,GenBank登录号FJ362388),茂汶过路黄(L.stellarioides,GenBank登录号FJ362384),腺药珍珠菜(L.stenosepala,GenBank登录号FJ362385),其中后2个种是国际上首次得到的。采用Blast方法将测序结果进行同源搜索,采用邻接法构建与其相关植物的ITS序列系统发育树。结果表明,珍珠菜属7种植物ITS序列总长度为613~620 bp;ITS1区序列长度为234~239 bp,5.8SrDNA区序列长度163 bp,ITS2区序列长度216~219 bp,7种植物的ITS序列差异主要集中在ITS1与ITS2区。聚类分析将茂汶过路黄聚为一支,其它6种植物聚为一支,表明茂汶过路黄与其它6种植物的碱基差异较大,从分子水平上支持据形态特征把花辐射生长的茂汶过路黄另立一类。     

基于ITS序列探讨珍珠菜属过路黄组的系统关系

测定了紫脉过路黄、临时救和过路黄的nrDNA ITS序列,并分析了珍珠菜属过路黄组17个物种的遗传距离及亲缘关系。结果表明,过路黄组植物的ITS序列长度在620～628间,一致性高达90.59%,种间遗传距离为0.002～0.199。系统发育树表明:(1)紫脉过路黄、临时救和小茄亲缘关系较近;(2)大叶过路黄、落地梅和过路黄亲缘关系较近;(3)山萝过路黄、贯叶过路黄、管茎过路黄、叶头过路黄、峨眉过路黄及三角叶过路黄亲缘关系较近。ITS序列分析结果为组内植物的鉴定、分类及系统进化提供了新的参考。     

Phylogenetic relationships of sect.Nummularia (Lysimachia):evidence from ITS sequences

测定了紫脉过路黄、临时救和过路黄的nrDNA ITS序列,并分析了珍珠菜属过路黄组17个物种的遗传距离及亲缘关系.结果表明,过路黄组植物的ITS序列长度在620～628间,一致性高达90.59%,种间遗传距离为0.002～0.199.系统发育树表明:(1)紫脉过路黄、临时救和小茄亲缘关系较近;(2)大叶过路黄、落地梅和过路黄亲缘关系较近;(3)山萝过路黄、贯叶过路黄、管茎过路黄、叶头过路黄、峨眉过路黄及三角叶过路黄亲缘关系较近.ITS序列分析结果为组内植物的鉴定、分类及系统进化提供了新的参考.     

两种过路黄的核型研究

对国产报春花科（Ｐｒｉｍｕｌａｃｅａｅ）珍珠菜属（Ｌｙｓｉｍａｃｈｉａ）植物过路黄（Ｌ.ｃｈｒｉｓｔｉｎａｅＨａｎｃｅ）和疏节过路黄（Ｌ.ｒｅｍｏｔａＰｅｔｉｔｍ）的核型进行了首次报道。过路黄染色体数目为２ｎ＝２４,核型公式为２ｎ＝２４＝２ｍ＋４ｓｍ＋６ｓｔ＋１２ｔ,核型类型“３Ａ”;疏节过路黄染色体数目为２ｎ＝２２,核型公式为２ｎ＝２２＝４ｍ＋６ｓｍ＋２ｓｔ＋１０ｔ,核型类型“３Ａ”。     

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.