前体、诱导子及抑制剂对细胞培养生产紫杉醇的调节作用

研究了前体、诱导子和抑制剂对中国红豆杉细胞培养生产紫杉醇的影响。结果表明 ,它们之间的协同作用对提高紫杉醇的产量有显著影响。其中向培养基中加入 30mg/L 3 甲基 2 丁烯 1 醇 ,2mmol/L苯甲酸钠 ,10mg/L氯化氯胆碱 (CCC) ,10 0 μmol/L茉莉酸甲酯 (MJ) ,0 1mmol/L丝氨酸 (Ser)可以使紫杉醇含量增加 1141 1%。     

补料培养与溶氧控制联合应用对红豆杉细胞培养的影响

为进一步提高红豆杉 (Taxuschinensis (Pilg.)Rehd .)细胞培养过程中紫杉醇的产量 ,采用细胞悬浮培养方法研究了补料培养与溶氧控制联合应用对紫杉醇产量的影响。 5L反应器中补料培养研究表明 ,培养过程中第 16天添加含 2 0g/L蔗糖的补料培养液有利于细胞的生长及紫杉醇的合成。 2 0L反应器中补料培养的研究结果表明 :2 0 %饱和度培养时紫杉醇含量最高 (0 .98mg/gDW) ,但 4 0 %～ 6 0 %溶氧饱和度能提高紫杉醇的产量。进一步研究表明 ,细胞在 6 0 %溶氧饱和度培养 2 0d后转入 2 0 %溶氧饱和度继续培养 12d ,能显著提高紫杉醇产量。补料培养与溶氧控制联合应用时 ,2 0L反应器中红豆杉细胞培养紫杉醇产量可达 18.7mg/L。     

新疆雪莲愈伤组织诱导及总黄酮的测定

以新疆雪莲植株叶片为外植体,研究了不同植物激素和培养时间对新疆雪莲愈伤组织生长、总黄酮含量和产量的影响.结果表明:新疆雪莲愈伤组织最佳诱导培养基为MS+2.00 mg/L NAA+1.00 mg/L 6-BA,其愈伤组织诱导率最高(97.0%);继代培养基以MS+2.00 mg/L NAA+1.00 mg/L 6-BA中愈伤组织生长量和总黄酮产量最高,分别达4.58 g和12.24 mg;以MS+4.00 mg/L NAA+2.00 mg/L 6-BA中的愈伤组织总黄酮含量最高,达2.17 mg/g;愈伤组织的生长量随继代培养时间的延长而增加,而其总黄酮含量不稳定,于继代培养第30天达到最高(2.7 mg/g),此时总黄酮产量最高可达26.66 mg.     

细胞均一性对葡萄细胞生长和花青素合成的影响

通过色差筛选法建立了一个相对均一的葡萄细胞悬浮系E,其细胞团较小,在长期继代培养过程中花青素合成能力的变异系数为8.7%,重复摇瓶实验的变异系数为5%。以E为实验材料进行的各组前体饲喂、诱导子添加、光照等联合作用实验,其生物量和花青素合成的变异系数均可控制在12%以内,充分说明了培养体系的均一性对维持稳定生产的重要性;黑暗条件下添加30μmol/L苯丙氨酸(Phe)和218μmol/L茉莉酸甲酯(MeJA)可使单位细胞花青素含量达到对照组的5.89倍,花青素产量为对照组的4.30倍,且连续5次继代培养过程中生物量和花青素合成的变异系数均比对照组降低。     

花生幼叶为外植体的植株再生系统的建立

本文报道利用花生成熟胚幼叶为外植体获得高频植株再生的方法,为花生转基因提供有效的受体系统。通过诱导培养基TDZ、BA、NAA的浓度以及种子萌发时问、继代培养基种类五个因素不同水平的正交试验,筛选出了分化高频发生的最佳组合为：MS培养基中应含有TDZ 1．0／μmol／L、BA0．4μmol／L、NAA5．0μmol／L,种子萌发4d,继代培养基为MS0。本研究表明,五因素中诱导培养基TDZ浓度为诱导花生幼叶分化的主要影响因素,其次为继代培养基、种子萌发时问,而诱导培养基中BA和NAA的浓度作用较小。试管苗生根后移栽田间,可正常开花结果。     

花生幼叶为外植体的植株再生系统的建立

本文报道利用花生成熟胚幼叶为外植体获得高频植株再生的方法,为花生转基因提供有效的受体系统。通过诱导培养基TDZ、BA、NAA的浓度以及种子萌发时间、继代培养基种类五个因素不同水平的正交试验,筛选出了分化高频发生的最佳组合为：MS培养基中应含有TDZ 1.0 μmol/L、BA 0.4 μmol/L、NAA 5.0 μmol/L,种子萌发4 d,继代培养基为MS0。本研究表明,五因素中诱导培养基TDZ浓度为诱导花生幼叶分化的主要影响因素,其次为继代培养基、种子萌发时间,而诱导培养基中BA和NAA的浓度作用较小。试管苗生根后移栽田间,可正常开花结果。     

茉莉酸甲酯与真菌诱导物、水杨酸组合对红豆杉细胞中紫杉醇含量的影响

比较了茉莉酸甲酯与真菌诱导物、水杨酸组合对红豆杉细胞几个抗病相关指标（POD、CAT活力、H2O2含量）及紫杉醇含量的影响,3种信号分子的组合对POD、CAT、H2O2及紫杉醇含量的影响是不一致的,MJ单独添加,MJ与SA联合作用以及MJ与F5联合作用都可使POD活力增加,且12h后H2O2含量均升高,约在48h达到高峰,为对照的2倍左右,但72h后,MJ单独添加和MJ与SA联合作用组中H2O2含量变化不大,F5与MJ联合作用则使H2O2含量持续比对照高。MJ单独添加使CAT酶活在144h后才较对照低,F5、SA的加入都可使CAT酶活下降,SA的作用更显著。说明三者的诱导途径并不完全一样,以SA和MJ联合添加对紫杉醇合成的促进作用最大,含量达到细胞干重的0．04％。     

氮离子注入对草麻黄成熟胚诱导愈伤组织的影响

以草麻黄为材料,研究了不同剂量的N^＋注入对成熟胚诱导愈伤的影响,并对激素配比进行了优化实验。结果显示：对于草麻黄成熟胚愈伤诱导及继代培养,最佳激素配比为2mg／L2,4-D＋2mg／L 6-BA。剂量为3．0～5．0×10^16 ions／cm^2的氮离子注入成熟胚后,其存活率与对照相比显著下降;2．0×10^16ions／cm^2的氮离子注入处理能显著提高愈伤组织的诱导率;此外,各继代时段,1．0～4．0×10^16ions／cm^2的4个氮离子注入处理其愈伤组织增长速度均高于对照,且随着注入剂量的增加而加快。     

水翁悬浮细胞系的建立及其悬浮培养的生长特性

建立了水翁悬浮细胞系,并对其悬浮培养的生长特性作了初步探讨。以水翁新生芽尖作为外植体,接种于添加有不同浓度和配比的生长调节物质及各种附加物的MS固体培养基中,诱导培养产生初代愈伤组织;挑选Ⅰ和Ⅱ型的愈伤组织进行继代培养改良,考察愈伤组织的生长状况和统计生长量来决定最佳继代培养基的配方和得到适合悬浮培养的愈伤组织;将以上得到的愈伤组织转接于最佳继代液体培养基中,于24±1℃,120r/min条件下振荡培养,筛选分散度好、较均匀、生长快、色浅透明的细胞作为种子传代,数次传代后得到性能良好的悬浮细胞系;以细胞生长量(鲜重)为指标,绘制了水翁悬浮细胞的生长曲线。研究表明:2.0mg/L的2,4-D的诱导率最高(92%,初代愈伤组织为Ⅰ型),Ⅱ型愈伤组织的最高诱导率为75%;最佳的继代培养基配方为MS 0.5mg/L 2,4-D 0.5mg/L 6-BA 1.0mg/L IAA 0.5mg/L IBA 0.5mg/L NAA 0.1mg/L KT 700mg/L LH,形成Ⅱ型愈伤组织的生长量可达3.28g/瓶(鲜重);液体继代培养3代后,可得到性能良好的悬浮细胞系;水翁悬浮细胞的生长曲线表明,最佳接种期为培养后的16~18d。     

狗牙根颖果胚性愈伤组织的诱导和胚性细胞的超微结构及植株再生

以普通狗牙根[Cynodon dacylon(L.)Pers.cv.'Suncitv']颖果为外植体,以MS为基本培养基,外加浓度在2.0～6.0mg/L的2,4-D,能高频率地诱导出高质量的胚性愈伤组织,其中以4.0 mg/L为最佳.胚性愈伤组织最佳继代及分化的培养方法为:用MS 2,4-D 4.0mg/L继代1～2次,然后转入1/2 MS 2,4-D 2.0 mg/L中继代1～2次,再在无激素的1/2MS中光照培养10 d,最后在MS 6-BA 3.0 mg/L中诱导分化,分化成苗率达31.7%.经电镜观察发现,胚性愈伤组织结构紧密,细胞较小,内容物丰富,而非胚性愈伤组织结构疏松,细胞巨大,内含一大液泡,几无细胞器.     

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.