几种典型藻华生物的分子分类学分析

通过PCR克隆测序、rDNA序列分析、随机PCR引物扩增结合DGGE技术等三个层次的分子分类水平对厦门海域的典型藻华生物进行分子生物学分析。结果表明,基于DGGE检测的18S rDNA序列过于保守,分类的精确度不高;AP-PCR则是基于基因组的差异进行分析,结果较为精确和全面;而rDNA序列分析相对可靠,尤其是针对ITS的长度和全序列分析以及28S rDNA的D1、D2区的序列分析,可以提供更为准确的分类信息,并可为设计检测探针提供基础。据此对分离自厦门海域的3种典型甲藻及其相关藻株建立了系统进化树。针对23株甲藻ITS序列建立的系统进化树显示Takayama pulchella（AY764179）和Karlodinium micrum的距离最近,并能够把Akashiwo属、Karenia属、Gyrodinium属、Karlodinium属、Takayama属与Gymnodinium属等区分开。用28S rDNA序列建立的系统发育树只能把Karlodinium属、Karenia属和Takayama属区分开,但不能很好地把无纹环沟藻与Akashiwo属和Gymnodinium等的藻区分开。     

中国近海甲藻环沟藻属2个新记录种:纺锤环沟藻和莫氏环沟藻

甲藻环沟藻属于一类无色素体、表面有脊的裸甲藻, 因可捕食一些重要的赤潮生物而在海洋生态系统中扮演着重要的角色。有关中国近海环沟藻属的物种多样性信息非常有限。本文报道了2个新记录种——纺锤环沟藻(Gyrodinium fusiforme)和莫氏环沟藻(G. moestrupii)。纺锤环沟藻细胞呈纺锤形, 长48.0-58.0 μm, 宽18.0-23.0 μm, 长宽比为2.4-3.0, 和模式种相比体型和长宽比都较小。莫氏环沟藻细胞也呈纺锤形, 长约30 μm, 宽约15 μm。我们测定了纺锤环沟藻和莫氏环沟藻大亚基的部分序列, 并根据大亚基序列利用最大似然法和贝叶斯法建立了系统发育树。结果显示环沟藻属是单源的, 纺锤环沟藻和裂缝环沟藻(G. fissum)聚合在一起, 但是与螺旋环沟藻(G. spirale)分离。纺锤环沟藻和莫氏环沟藻分别可以摄食米氏凯伦藻(Karenia mikimotoi)和具齿原甲藻(Prorocentrum dentatum), 前者在米氏凯伦藻赤潮中的大量出现显示它可以促进赤潮的消退。     

甲藻分类历史沿革及中国近海部分甲藻分类地位修订

甲藻自发现至今已有200多年的历史.一方面,甲藻的分类地位越来越受到学者的重视;另一方面,随着研究的深入,出现了越来越多的争议和困惑,在一定程度上阻碍了甲藻分类学的发展.本文简述了国内外甲藻分类研究的历史沿革,主要介绍了几次较大的分类地位的变革.另外,目前中国近海甲藻的分类体系与国际上通用的分类体系还有很多差异,为了更好地促进国内甲藻的分类学研究,方便国际间的合作与交流,我们对国际国内的甲藻分类体系(分别以algaeBASE数据库和《中国海洋生物名录》为代表)进行比较,发现目水平上的分类体系基本相同,但在科、属的划分上有很多差异.针对这些差异点查阅文献,寻根溯源,最终提出了一个较为合理的划分.本文所作的主要调整有:将凯伦藻属(Karenia)、卡罗藻属(Karlodinium)和塔卡藻属(Takay ama)3个属从裸甲藻科(Gymnodiniaceae)中分出,单独成凯伦藻科(Kareniaceae);角藻属(Ceratium)中的大部分海洋种改为新角藻属(Neoceratium);亚历山大藻属(Alexandrium)从屋甲藻科(Goniodomataceae)中分出,归入膝沟藻科(Gonyaulacaceae);取消异沟藻科(Heteraulacus),由屋甲藻科取而代之;成立2个新目,即尖尾藻目(Oxyrrhinales)和梨甲藻目(Pyrocystales).     

藻毒素的类型、危害和防治

介绍了赤潮藻毒素：麻痹性贝毒、短裸甲藻毒素、溶血性毒素、细胞性毒素和氨毒：水华藻毒素：肝毒素、神经毒素、脂多糖内毒素的化学结构、性质和毒害机理等,以及藻毒素的防治方法。     

前沟藻18S rDNA序列克隆和分子鉴定分析

旨在扩增一株未知微藻18S rDNA,并进行序列分析和物种鉴定分析.提取该微藻总DNA,用PCR技术扩增其18S rDNA,对序列进行测序,在GenBank进行序列比对分析,用ClustalX软件构建进化树;用光学显微镜进行形态学分析.经测序其序列长度为1 736 bp,G+C为47％;同源性分析表明,与GenBank中多个强壮前沟藻种的18S rDNA基因序列同源性迭99％;与前沟藻属的其它藻种同源性均迭95％以上.而与裸甲藻属和环藻属的藻株同源性为85％左右.经光学显微镜观察,该藻具有典型的强壮前沟藻形态.结合该藻18S rDNA序列分析和粗略的形态学分析,推断该藻可能为前沟藻属的强壮前沟藻.微藻形体微小,结构简单,需借助电子显微镜才可准确地从形态学上签定其种属,鉴定工作繁琐费时;而利用分子技术,则可能使鉴定工作变得简单快捷.     

不同影响因子对裸甲藻生长的影响

目的:考察盐度、pH值、接种时期、维生素和微量元素对一种裸甲藻生长的影响。方法:采用配制不同条件海水加富培养液培养裸甲藻,计算藻细胞密度来考察裸甲藻的生长情况。结果:该种裸甲藻在其他培养条件确定的情况下,能够适应生长的盐度范围为15~30;弱酸性(pH 6)的培养液最利于其迅速生长;对数期接种保证藻细胞连续生长;维生素不是裸甲藻增殖的必要因素,而微量元素是其生长的必要条件,易成为裸甲藻生长的限制因素。     

不同pH和盐度下海洋细菌对赤潮藻生长和产毒的影响

研究了在可控生态条件下。一株分离自厦门西海域沉积物的海洋细菌S10在不同pH和盐度条件下对赤潮原因种塔玛亚历山大藻(Alexandrium tamarense)生长和产毒的影响．结果表明。实验用藻株适宜生长pH为6～8,适宜盐度为20～34;该藻株在不同pH及不同盐度条件下,藻细胞毒力差异显著,且随着pH升高而下降。随着盐度增加而加大,到盐度为30时达到最高值。然后逐渐下降;菌株Sl0(1．02×10^l0cells·ml^-1)在pH7～9和盐度15～34下均能有效抑藻生长和产毒。且在pH7、盐度34时其抑藻生长作用最强;在pH7时抑藻产毒效果较好,且其抑藻产毒作用强度不随盐度变化而异．     

广东省水库微囊藻的产毒特征和ITS序列的遗传多样性分析

为了解广东省水库微囊藻的产毒特征和ITS 序列的遗传多样性,从广东省供水水库中分离得到28 株微囊藻(Microcystisspp.),对它们的产毒特征和15 株微囊藻的ITS 序列进行了分析.高效液相色谱(HPLC)和微囊藻毒素合成酶基因mcyE 的检测结果表明,广东省水库中的微囊藻以产毒藻株占优势,微囊藻毒素的主要类型为MC-RR.广东省15 株藻株的ITS 序列相似性大于93.2%,在用相邻法(NJ)构建的系统树上,不同形态的种和不同地理区域的藻株没有区分开,产毒和非产毒藻株没有形成独立分支.这说明微囊藻ITS 序列的遗传多样性较低,ITS 序列和mcyE 存在没有相关性,表型不能够反映藻株的进化关系.因此,有必要将藻类传统分类方法与分子方法结合起来对蓝藻进行重新分类.     

东海剧毒卡尔藻的形态特征及其系统进化分析

利用光学显微镜、荧光显微镜、扫描电镜及分子生物学等方法, 对分布于我国东海海域的剧毒卡尔藻（Karlodinium veneficum）藻株（LAMB090611）的形态特征和显微结构进行了描述, 并探讨了其分子系统进化关系。该藻株细胞长11.1-18.7 μm, 平均值为（14.2±1.8） μm, 宽8.2-14.7 μm, 平均值为（10.8±1.5） μm。细胞形态结构特征为： 上下锥体积基本相同; 顶沟短而直; 腹孔明显; 纵沟延伸至上锥; 横沟错位距离约占细胞总长的28%-38%; 含有2或4个不规则形态的叶绿体; 细胞核位于中部或下锥。此藻种的暴发可引发有害赤潮（harmful algal bloom）。当前加强有害赤潮的预防和监测工作是减少危害的有效途径, 而对引发赤潮原因种的准确识别和鉴定则是基础和关键。     

嵊山岛海洋药用生物资源状况调查

对嵊山岛礁生物资源以及邻近海域的微藻资源调查,共发现121种潮间带生物,其中有28种海洋药用生物,包括红条毛肤石鳖(Acanthochiton rubrolineatus)、马粪海胆(Hem icentiotus pulcherrimus)、海萝(Gloiopeltis furcata)等,其中多数是海洋中药或可制成中成药,嵊山岛丰富的海绵资源具有筛选天然活性物质的潜力。嵊山岛邻近海域的产毒藻类包括产麻痹性贝毒(PSP)的链状亚历山大藻(Alexandrium catenatum)、塔玛亚历山大藻(Alexandrium tamarens),产腹泻性贝毒(DSP)的倒卵形鳍藻(D inophysis forti)、具尾鳍藻(D inophysis caudata);产记忆缺失性贝毒(ASP)的尖刺拟菱形藻(Pseudo-Nitzschia pungens)、多列拟菱形藻(Pseudo-Nitzschia multiseries)和多纹拟菱形藻(Pseudo-Nitzschia multistriata);产神经性贝毒(NSP)的短凯伦藻(Kerina breve)以及红色裸甲藻(Gymnodinium sangium)、米氏凯伦藻(Kerina m ikim oto)、环状异甲藻(Heterocapsa circularisqua-ma)等能产生生理活性物质的藻类,其中嵊山岛邻近海域产石房蛤毒素和神经毒素的有毒藻类可能具有药用开发价值。     

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.