新疆猪毛菜属4种植物核型分析及进化研究

采用常规压片法,对钠猪毛菜、准噶尔猪毛菜、小药猪毛菜和薄翅猪毛菜等4种新疆猪毛菜属植物的染色体核型进行了分析,并对已报道的12种新疆猪毛菜属植物核型进行了比较.结果表明:(1)钠猪毛菜体细胞染色体数2n=2x=18=12m+6sm,准噶尔猪毛菜、小药猪毛菜体细胞染色体数为2n=2x=18=18m,该3种均属于1A型;薄翅猪毛菜体细胞染色体数为2n=2x=54=50m+2sm+2st,属2A型;(2)12种新疆猪毛菜属植物核型比较结果证明,猪毛菜属植物的染色体基数为9,钠猪毛菜、准噶尔猪毛菜和小药猪毛菜均为二倍体,薄翅猪毛菜为六倍体,钠猪毛菜和准噶尔猪毛菜具有随体.准噶尔猪毛菜、小药猪毛菜、薄翅猪毛菜属植物的核型均属于首次报道.     

百合科开口箭属六个种的核型研究

本文报道了开口箭属(Tupistra)6个种的核型,发现6个种皆为二倍体,染色体数目为38。他们的核型公式是:弯蕊开口箭(T. wattii)为2n=2x=38=38m;长梗开口箭(T. longipeduncuJara)为2n=2x=38=28m 10sm;橙花开口箭(T. aurantiaca)为2n=2x=38=22m 16sm;开口箭(T. chinensis)和云南开口箭(T. yunnanensis)皆为2n=2x=38=24m 14sm,核型皆为2B型,但sm染色体的位置有所不同;伞柱开口箭(T. fungilliformis)为2n=2x=38=18m 2sm 12st 6t。前述5个种的核型由一型染色体组成,而伞柱开口箭的核型由二型染色体组成。开口箭属和蜘蛛抱蛋属(Aspisdistra)是亲缘关系接近的两个属,伞柱开口箭是开口箭属和蜘蛛抱蛋属之间的一个过渡类群。     

香港喜盐草属植物的核型分析

报道了分布于我国香港特别行政区的喜盐草属(Halophila Thou.) 2种植物的染色体数目和核型,其体细胞中期染色体数目均为2n=18。它们的核型公式分别为：喜盐草(H. ovalis (R. Br.) Hook. f.) 2n=2x=18=4m+14sm;贝克喜盐草(H. beccarii Asch) 2n=2x=18=8m+10sm(首次报道)。核型均属于2B型。     

伞形花科5种主要蔬菜作物的核型分析

采用卡宝染色压片法对伞形花科5种主要蔬菜作物进行了核型分析和比较.结果表明:芹菜的核型公式为K(2n)=2x=22=6m+2sm+8st+6t,染色体核型为"3B"型;芫荽的核型公式为K(2n)=2x=22=2m+2sm+18st,染色体核型为"3A"型;茴香的核型公式为K(2n)=2x=22=14m+6sm+2st,染色体核型为"2B"型;水芹的核型公式为K(2n)=2x=22=6m+6sm+10st,染色体核型为"3A"型;胡萝卜的核型公式为K(2n)=2x=18=6m+10sm+2st,染色体核型为"2A"型.并对他们的亲缘关系、遗传多样性进行了探讨.     

风毛菊属5种植物的核型分析

采用常规压片法,对风毛菊属(Saussurea)5种植物的染色体数目和核型类型进行分析。结果表明:大耳叶风毛菊(S.macrota)核型公式为2n=2x=26=10m+12sm+4st,属2A型;长梗风毛菊(S.dolichopoda)核型公式为2n=2x=26=14m+8sm+4st,属2A型;川陕风毛菊(S.licentiana)核型公式为2n=2x=28=12m+16sm,属2B型;杨叶风毛菊(S.populifolia)核型公式为2n=2x=28=6m+18sm+4st,属2B型;尾叶风毛菊(S.caudata)核型公式为2n=2x=30=14m+14sm+2st,属2A型。这5种风毛菊属植物中,除大耳叶风毛菊染色体数目和核型类型与前人报道的一致外,其余4种植物的染色体数目和核型类型均为首次报道,并在川陕风毛菊中发现1对B染色体。     

加拿大一枝黄花入侵的细胞学机制

对入侵植物加拿大一枝黄花(Solidago canadensis L.)和同属土著种一枝黄花(Solidago decurrens Lour.)的染色体计数,并对核型进行了分析.实验结果:加拿大一枝黄花染色体数目为2n=54,核型公式为k(2n)=6x=54＝46m 8sm(0-6SAT),核型类型为2A型;一枝黄花染色体数目为2n=18,核型公式为k(2n)=2x=18=16m 2sm(0-2SAT),核型类型为1A型.通过对一枝黄花属(Solidago L.)植物染色体数目的统计分析,判断该属的染色体基数为9.通过对多倍体基因表达导致植物适应进化的讨论得出:多倍体是入侵植物特征,可能是植物入侵的内在机制.     

美人蕉核型研究

对美人蕉体细胞染色体计数,并对其核型进行分析。结果表明,美人蕉的染色体数目为2n=18,核型公式为2n=2x=18m,属于"1A"型。     

鸡骨常山属三个种的核形态

研究了鸡骨常山属（Alstonia）3个种的核形态,其中盆架树（A.rostrata）的核型属首次报道,3个种的体细胞染色体数目均为2n=42,且糖胶树（A.scholaris）和鸡骨常山（A.yunnanensis）的染色体数目同前人报道的2n=44不同。盆架树的间期核和有丝分裂前期染色体分别为棒状前染色体型和中间型,核型公式为2n=42=3M＋21m＋18sm,核型不对称性类型为2A型。糖胶树的间期核和有丝分裂前期染色体分别为球状前染色体型和中间型,核型公式为2n=42=14m＋24sm＋4st,核型不对称性类型为3A型。鸡骨常山的间期核和有丝分裂前期染色体分别为复杂染色体中央粒型和中间型,核型公式为2n=42=5m＋37sm,核型不对称性类型为3B型。根据核形态结果,结合形态学特征和已有的细胞学资料,初步讨论了该属几个种的系统位置及演化趋势。     

香水月季(Rosa odorata Sweet)不同变种的染色体及核型分析

采用常规压片法对采自11个地点的4个变种进行了以染色体形态和倍性为主的核型分析。结果表明:(1)香水月季原变种是2倍体,核型公式为:2n=2x=14=12m+2sm,核型为1A。(2)大花香水月季4个居群的染色体形态很相似,都是2倍体,核型全为1A,核型公式均是2n=2x=14=12m+2sm,居群间差异主要表现在染色体组的相对长度构成上。(3)桔黄香水月季是2倍体,核型公式为2n=2x=14=10m+4sm,核型为1A。(4)来自不同地方的粉红香水月季在染色体数量和形态上有较大的差异。木家桥和永春的是3倍体,核型公式分别为2n=3x=21=18m+3sm和2n=3x=21=21m;红桥、富民和小河的是2倍体,核型公式分别为2n=2x=14=12m+2sm、2n=2x=14=10m+4sm和2n=2x=14=12m+2sm;除富民的核型为1B外,其他地方的核型均是1A。基于研究结果,讨论了香水月季的核型特征、细胞遗传分化模式、丰富的变异及其在育种中的应用。     

橙花破布木染色体制片及核型分析

为了解橙花破布木的遗传背景,以其根尖为试验材料,采用体细胞染色体常规制片法着重探索取材和预处理两个实验环节,选取染色体分散较好的细胞进行数目确定及核型分析。结果表明:(1)橙花破布木最佳取材时间为9:30～10:00和14:00～14:30,最佳预处理试剂及时间为饱和对二氯苯预处理2h;(2)橙花破布木染色体数目为32条,共16对染色体,为二倍体植物;核型公式为2n=2X=32=32m,核型属于"1A"型;染色体组绝对长度变化范围为0.38～0.69μm,相对长度(%)变化范围为4.48～8.24,相对长度组成为2n=2L+14M1+14M2+2S;核型不对称系数(As.K%)为58.40%。研究结果为破布木属植物染色体制片技术及核型分析提供参考,也可为橙花破布木基因进行染色体定位等细胞遗传学及表观遗传学研究奠定基础。     

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.