应用基因表达谱芯片研究黄药子对小鼠肝脏的毒性机制(简报)

黄药子为薯蓣科植物黄独(Dioscorea bulbifera L．)的块茎,临床常用于治疗甲状腺肿、抗肿瘤、抗炎、抗病毒等。近年来临床上关于黄药子的毒副作用,尤其是对肝、肾的不良反应屡有报道。当黄药子或其代谢物在肝细胞内累积时会直接干扰肝细     

应用正交设计法优选黄独脱毒苗快繁培养基

通过正交设计法研究黄独脱毒苗的快繁培养基,考察KT、NAA和2,4-D对黄独脱毒苗快繁的影响。结果表明,黄独脱毒苗快繁的最佳培养基为MS+KT 2.0 mg/L+NAA 0.5 mg/L。     

黄独脱毒苗快繁及产业化技术探讨

以黄独脱毒苗为试材,采用植物组织培养方法研究不同因素对脱毒苗快繁技术的影响。结果表明,在黄独脱毒苗快繁中,白砂糖可替代蔗糖,果酱瓶可替代三角瓶,液体培养优于固体培养,但自来水不能代替蒸馏水。黄独脱毒苗在移栽的过程中,气孔关闭率在第5天时达到最高,以后气孔逐渐恢复关闭功能。脱毒苗与非脱毒苗的块茎在直径和鲜重上均有显著差异,表明黄独经脱毒后可提高产量。     

KT、2,4-D和NAA对黄独组培苗带芽茎段生长发育的影响

以黄独组培苗带芽茎段为材料,采用植物组织培养和单因子实验法,研究添加KT和2,4-D或KT和NAA组合的MS培养基对黄独带芽茎段再生的影响。结果表明,MS+KT 2.0 mg/L+NAA 0.5 mg/L有利于黄独带芽茎段腋芽萌发和根系生长。     

盐胁迫对黄独脱毒苗生长和若干生理生化指标的影响

通过在培养基中添加不同浓度NaCl,探讨盐胁迫对黄独脱毒苗生长及若干生理生化指标的影响。结果表明,在盐胁迫条件下,黄独脱毒苗的生长受到明显抑制,叶片中总叶绿素含量、SOD活性下降,丙二醛含量增加,脯氨酸大量积累;随盐胁迫强度的加大,对试管苗生长及生理生化指标的影响相应加剧;在盐胁迫下,黄独脱毒苗叶片脯氨酸含量与丙二醛含量呈极显著正相关,而与叶绿素含量和SOD活性呈极显著负相关。因此,盐胁迫下叶片中脯氨酸含量的变化可作为黄独脱毒苗受害程度的主要生理鉴定指标。     

黄独脱毒苗叶片和茎段再生体系的建立

以黄独茎尖再生苗为试材,研究不同因素对黄独脱毒苗叶片和茎段再生体系的影响,以期对黄独脱毒苗的再生体系进行优化。结果表明,叶片和茎段诱导愈伤组织的最佳培养基是MS+KT 2 mg·L^-1+2,4-D 2 mg·L^-1;叶片和茎段诱导愈伤组织的最佳蔗糖浓度分别为30和50 g·L^-1;叶片和茎段在黑暗中较容易诱导出愈伤组织;叶片和茎段愈伤组织分化的最佳培养基是MS+KT 4 mg·L^-1+NAA 0.1 mg·L^-1;继代2次的叶片和茎段愈伤组织较容易分化;黄独不定芽生根的最佳培养基是1/2MS+IBA 0.1 mg·L^-1+NAA 0.5 mg·L^-1+PP₃₃₃ 1 mg·L^-1。本实验成功建立了黄独脱毒苗叶片和茎段的再生体系,为黄独脱毒苗的工厂化生产奠定了技术基础。     

黄独冻后黑暗培养胚性愈伤组织及其再生植株的电镜观察

本研究以黄独为材料,对其冻后黑暗培养胚性愈伤组织及其再生植株进行电镜观察。结果表明:黄独胚性愈伤组织在冻后没有经过一定时间的黑暗培养直接放于正常的光周期下培养,极易使细胞内容物外泄,且造成部分细胞器和细胞核消失或裂解形成空隙,线粒体和高尔基体等细胞器的结构不完整,出现空隙或内容物溢出或断裂现象;而黄独冻后胚性愈伤组织经过3 d的黑暗培养后再置于光周期下培养,受损的细胞较少,细胞排列较紧密,且细胞器降解较少,很少出现空隙等现象,线粒体、高尔基体等细胞器的结构也较为完整。此外,与黄独带芽茎段常温继代再生试管苗相比,黄独胚性愈伤组织经过冻后黑暗培养后,其再生试管苗的根、茎、叶结构没有出现显著变化,且两者的气孔参数和叶绿体数量也均无显著性差异。本试验结果可为植物种质资源超低温保存后的黑暗培养提供了亚显微结构证据。     

黄独微型块茎鲨烯合酶的基因克隆与序列分析

通过黄独微型块茎转录组数据库筛选到SQS基因的核心片段,利用RT-PCR技术获得SQS基因保守片段,采用RACE技术获得SQS基因的3′及5′末端序列,并采用生物信息学方法进行序列分析。结果表明,黄独微型块茎SQS基因编码序列长1548 bp,编码415 bp的氨基酸序列,理论分子量为46786.38 D,等电点(pI)为5.97。SQS蛋白为疏水性蛋白,无信号肽,含有SQS所必需的功能结构域,属于Isoprenoid_Biosym_C1 superfami?ly。黄独SQS蛋白与其他植物的SQS蛋白同源性较高,其中与盾叶薯蓣的SQS蛋白氨基酸相似性为96.4%。本试验结果从黄独微型块茎中首次获得SQS基因cDNA全长序列,该基因具有SQS同源基因的典型特征,为进一步研究黄独微型块茎SQS基因结构、基因表达和基因突变提供了基础,并为薯蓣属植物三萜合成通路关键酶SQS的正选择位点与功能的关联性分析提供了数据支持。     

中国薯蓣属基生翅组分类修订

在查阅标本、野外调查和长期引种观察的基础上,对中国薯蓣属(Dioscorea Linn.)基生翅组(Sect.Opsophyton Uline)植物的形态进行了比较和总结,并进行了分类学修订,编制了检索表。结果表明:根据花、果实、叶片和珠芽(零余子)形态,修订后的中国薯蓣属基生翅组包括黄独(D.bulbifera Linn.)及其变种,分别为黄独(原变种)(D.bulbifera var.bulbifera Linn.)、白金山药(D.bulbifera var.albotuberosa Y.F.Zhou,Z.L.Xu et Y.Y.Hang)、异叶黄独(D.bulbifera var.heterophylla Prain et Burkill)、大花黄独(D.bulbifera var.simbha Prain et Burkill)和短序黄独(D.bulbifera var.brachybotryum Y.Y.Hang et Y.F.Zhou)。其中,新变种1个,即短序黄独。将分布于海南的原名为雷公薯处理为异叶黄独。     

与黄独(Dioscorea bulbifera)性别相关的RAPD-SCAR标记研究

对黄独(Dioscorea bulbiferaL.)14个居群42个单株的总DNA进行RAPD分析,并根据测序结果合成1对特异的SCAR引物,即5′-GGCTTCTGTCACTACATGGG-3′和5′-GGCTTCTGTCCAGTGCATCT-3′,对42个单株的总DNA进行检测,扩增到1条长681 bp的与雄性相关的特异片段。除形态上有一定变异的4个单株外,这个与雄性相关的RAPD-SCAR标记在黄独原变种的29个单株中验证准确,在可能为其变种的9个单株中部分验证准确,表明该RAPD-SCAR标记能够准确标记黄独的原变种及一些变种的雄性性别。     

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.