鲫不同种系线粒体DNA物理图谱的构建

用１３种限制性内切酶对鲫鱼三个亚种共七个品系的线粒体ＤＮＡ进行分析,其中有９种酶在种系间或种系内产生限制性片断长度多态性,发现了１６个线粒体ＤＮＡ组合单倍型,通过双酶切分析,构建了１６个线粒体ＤＮＡ组合单倍型的１３种限制性内切酶的发点的物理图谱。     

鱼类基因组结构研究——Ⅰ.染色体的限制性内切酶显带

本文报道了1种新的鱼类染色体研究方法——限制性内切酶显带技术。我们应用限制性内切酶Bsp631等分别对黄鳝和长春鳊的染色体进行显带处理,结果表明,Bsp631能使这两种鱼的染色体发生稳定的带纹分化:适度的处理产生多重的G-带状带型,而过度的处理则产生特殊的限制性内切酶抗性带型。根据显带结果分析,我们对鱼类染色体限制性内切酶显带的可行性和实用价值进行了讨论。     

三江白猪线粒体DNA的多态性

采用22种限制性内切酶分析了三江白猪mtDNA多态性。在60头个体中检出30种限制性态型,归结为7种基因单倍型;其间的差异来自少数限制性位点的突变。单倍型间平均遗传距离为0．35％,群体遗传多态程度为0．044％。三江白猪遗传多样性非常贫乏,说明三江白猪与地方种猪起源于一个共同祖先,在品种形成早期受到创立者效应的制约。     

实时检测限制性内切酶活性的发夹型荧光探针

基于分子信标的原理 ,设计了一种发夹型荧光探针作为限制性内切酶作用的专一底物 ,来研究限制性内切酶的剪切作用。检测BglII和NcoI表明 ,这种探针不仅可以灵敏、实时地指示内切酶的活性 ,采用不同荧光标记的探针还可以同时特异地显示双酶切反应中两个酶各自的活性。并且以Rotor Gene 2 0 0 0实时荧光PCR仪作仪器检测 ,实现了高通量的操作。利用其特有的作变温曲线的功能 ,能很好的区分限制性内切酶与发夹型荧光探针的特异剪切与非特异的结合     

中国主要鹅品种的线粒体DNA多态性与起源分化研究

运用19种限制性内切酶对中国11个家鹅品种138个样本进行了mtDNA的限制性片段长度多态性（RFLP）分析。在使用的19种内切酶中,有7个酶检测出多态。综合27种限制性态型（restrictionmorph）,可得到6种mtDNA单倍型（hopotype）。伊犁鹅与另外10个鹅品种没有共享的单倍型,遗传距离和UPGMA聚类分析也表明,伊犁鹅与这些品种具有不同的起源。EcoRV、HaeⅡ、HincⅡ和KpnⅠ4种酶的限制性态型可作为鉴别两种起源家鹅的母系遗传标记。起源于鸿雁的10个鹅品种群体内出现一定的遗传差异,其群体多态度（π）、单倍型间平均遗传距离（P）、品种间平均净遗传距离（δnet）分别为0．025％、0．266％和0．029％。白羽鹅品种在形成过程中经历过创立者效应（foUndereffect）。这10个鹅品种可能起源于两个不同地理区的鸿雁类群。     

板齿鼠线粒体DNA的研究

本文应用ＡｐａＩ、ＢａｍＨＩ、ＢｃｌＩ、ＢｇｌＩ、ＣｌａＩ、ＥｃｏＲＩ、ＥｃｏＲＶ、ＨｉｎｄＩＩ、ＰｓｔＩ、ＰｖｕＩＩ、ＳａｃＩ、ＳｃａＩ和ＸｂａＩ等１３种限制性内切酶对板齿鼠线粒体ＤＮＡ（ｍｔＤＮＡ）进行限制性片段长度多态（ＲＦＬＰ）分析,并用双酶解法构建其限制性内切酶图谱。结果表明板齿鼠存在３种ｍｔＤＮＡ单倍型,可通过限制酶ＰｖｕＩＩ、ＨｉｎｄＩＩ和ＡｐａＩ区分,呈现ＤＮＡ多态性和种内遗传变异。与小家鼠、褐家鼠ｍｔＤＮＡ限制性片段的数据相比较,板齿鼠和这两种鼠ｍｔＤＮＡ存在明显差异。板齿鼠ｍｔＤＮＡ限制性内切酶图谱的建立,为进一步系统研究鼠科动物的遗传分化提供了依据。     

贵州四个山羊品种mtDNA多态性及起源分化

采用１５种限制性内切酶,研究贵州省４个山羊品种共９３只个体的线粒体ＤＮＡ多态性。其中ＢｏｍＨＩ、ＨｉｎｄⅢ和ＳａｌⅠ３种酶的酶切类型存在多态。共检测到１８种限制性态型,归结为３种ｍｔＤＮＡ单倍型。单倍型Ⅰ、Ⅱ在贵州山羊４个品种分布频率较高,分别为７７．４２％和２１．５０％,单倍型Ⅲ分布频率较低（１．０８％）;品种间亲缘关系聚类分析表明白山羊和黑山羊亲缘关系最近,其次为黔林羊,而与小香羊的亲缘关系最     

谷氨酸产生菌噬菌体的限制性内切酶分型

噬菌体污染在全国各地味精厂广泛存在,严重的污染常导致发酵中期倒罐。肇致巨额经济损失,我们从上海,沈阳,山东、武汉等地味精厂发酵环境及异常发酵液中分离出多株噬菌体,鉴于目前常用的噬菌体的分型标准具有某些局限性,我们试用DNA的限制性内切酶谱来区分噬菌体的型别。根据3种指标分别对8株噬菌体分型:按限制内切酶Bam H Ⅰ和Pst Ⅰ图谱分为7型。按宿主范围分为2型-按形态特征分为5型,这些结果不仅说明限制性内切酶分型是比宿主范围、形态特征更为灵敏的指标,而且表明限制性内切酶Pst Ⅰ和Bam H Ⅰ作为对噬菌体的分型标准是可行和方便的。     

猪线粒体DNA多态性与中国地方猪种起源分化的关系

用24种限制性内切酶分析了我国21个具代表性地方猪品种、1个引进品种和2个来自中国和越南的野生近缘种mtDNA的RFLP。结果表明:在74个个体中检出的32种限制性态型可归结成7种单倍型,其间的差异主要来源于少数几个限制性位点的点突变;地方猪种4种单倍型间的平均遗传距离为0.143％,遗传多态程度(π值)仅为0.007％,说明遗传多样性非常贫乏,提示中国地方猪种可能起源于一个野猪亚种。     

贵州汉族,苗族,布依族和水族人群线粒体DNA多态性研究

本文运用１６种限制性内切酶对来自贵州的汉族、苗族、布依族和水族的１５０个样本进行了ｍｔＤＮＡ的限制性片段长度多态性（ＲＦＬＰ）分析。共检测到３１种限制性格局（Ｒｅｓｔｒｉｃｔｉｏｎｐａｔｔｅｒｎ）,其中ＨａｅＩＩ－１３型、ＥｃｏＲＶ－３型和ＰｓｔＩ－４型３种限制性格局为新报道综合这些限制性格局,共得出２８种ｍｔＤＮＡ类型（ｍｔＤＮＡｔｙｐｅ）。运用ＵＰＧ法和简约法分析了各ｍｔＤＮＡ类型之间、各人群之间的聚类关系,结果表明：水族人群的ｍｔＤＮＡ变异度较大;汉族和苗族的亲缘关系最近,布依族和水族有着较远的亲缘关系。     

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.