茶树叶肉原生质体的分离与纯化

以茶树幼苗叶片为材料,分析了甘露醇浓度、不同酶液组合、酶解时间等因素对叶肉原生质体分离及2种高密度分离液对原生质体纯化的影响。结果表明,叶片在含0.6 mol/L的甘露醇、1.5%的纤维素酶和2.5%的离析酶的酶解液中黑暗酶解16~18 h,叶肉原生质体的分离效果最好。此外,研究发现原生质体在10%的甘露醇与25%的碘克沙醇界面处聚集形成了一条带。     

三倍体‘银中杨’叶肉原生质体制备的优化

以三倍体杨树品种‘银中杨’（Populus alba×P.berolinensis Yinzhong）无菌苗叶片为材料,对其原生质体分离及纯化条件进行研究,为进一步通过细胞融合、基因工程等进行品种改良探索新的途径。结果表明：酶的种类及浓度、渗透压、酶解时间对‘银中杨’叶肉原生质体分离效果有显著影响,适宜的分离条件为CPW+3% Cellulase RS+0.5% Macerozyme R-10+0.3% Pectinse Y-23+0.6 mol/L甘露醇+0.6 g/L MES+1 g/L BAS,酶解时间为8 h,原生质体产量和活力分别为2.13×10⁷个/g和80.18%;‘银中杨’叶肉原生质体纯化最佳方法为上浮法蔗糖等密度离心,且蔗糖浓度为40%时原生质体产量最高（1.06×10⁷个/g）,可满足进一步的原生质体培养等技术的要求。     

沙冬青子叶原生质体瞬时表达体系的建立及其AmDREB1蛋白的亚细胞定位

以沙冬青(Ammopiptanthus mongolicus(Maxim.ex Kom.)Cheng f.)幼苗的子叶为材料,对其原生质体的分离、纯化和瞬时表达体系进行了研究。结果表明,子叶原生质体分离的最佳酶解液组成为CPW溶液+3.0%纤维素酶R-10+0.5%离析酶R-10+0.3%半纤维素酶+9.0%甘露醇(p H5.8);最佳酶解条件为室温、避光、40 r/min轻摇14 h。采用W5溶液作为漂洗液将酶解物稀释后进行过滤,将过滤液在4℃、700 r/min条件下离心5 min,所得纯化原生质体的产量约为2.50×106cells/g,活力达到90%;以纯化的原生质体作为受体,利用聚乙二醇(PEG)介导法成功将植物瞬时表达载体p BI-GFP导入其中,转化效率达到50.8%。利用本研究建立的原生质体瞬时表达体系,检测到沙冬青脱水应答转录因子Am DREB1定位于细胞核内。     

菠菜原生质体游离与纯化的研究

以菠菜为实验材料进行原生质体分离、纯化、活力鉴定。结果表明:1.5%纤维素酶OnozukaR-10+1%果胶酶Pectolase+0.5mol/L甘露醇+CPW盐的酶液,酶解时间5h,菠菜原生质体的获得率高。纯化时,适当降低离心时间有利于原生质体纯化过程中产量及活力的保持,500r/min离心5min,效果较好。     

虎杖原生质体分离纯化及电融合初步研究

以野生虎杖根状茎芽为外植体诱导虎杖愈伤组织,选取生长状况良好的愈伤组织作为原生质体分离材料,通过L16（44）正交试验对虎杖原生质体分离条件进行优化.结果表明：1.4%纤维素酶R-10,0.1%果胶酶,17%甘露醇的酶液,酶解时间7h,虎杖原生质体分离效果最好.在80r/min振荡分离后虎杖原生质体得率为46.2%.以800r/min的离心速度纯化,纯化的原生质体得率为43.8%,其中原生质体的成活率为75%.通过对虎杖原生质体进行融合,原生质体的融合率为20.2%.     

虎仗原生质体分离纯化及电融合初步研究

以野生虎杖根状茎芽为外植体诱导虎杖愈伤组织,选取生长状况良好的愈伤组织作为原生质体分离材料,通过L16(44)正交试验对虎杖原生质体分离条件进行优化.结果表明:1.4%纤维素酶R-10,0.1%果胶酶,17%甘露醇的酶液,酶解时间7h,虎杖原生质体分离效果最好.在80r/min振荡分离后虎杖原生质体得率为46.2%.以800r/min的离心速度纯化,纯化的原生质体得率为43.8%,其中原生质体的成活率为75%.通过对虎杖原生质体进行融合,原生质体的融合率为20.2%.     

新疆杨愈伤组织原生质体的游离与纯化

目的:以愈伤组织为材料,研究新疆杨原生质体的游离、纯化。方法:以新疆杨愈伤组织为材料,采用简单试验设计和方差分析方法,对新疆杨原生质体游离的影响因素进行研究,并利用二乙酸荧光素染色法观察原生质体活力。结果:适宜新疆杨愈伤组织原生质体游离的较适宜条件是:CPW+2.0%纤维素酶R-10+1.0%离析酶R-10+1.0%果胶酶Y-23+0.6 mol/L甘露醇,酶解温度27℃,酶解时间8 h。在此条件下,原生质体产量达8.5×106个/(g.FW),活力达83.6%。原生质体纯化可采用蔗糖等密度离心法,较适蔗糖浓度为30%。结论:研究筛选出的酶解因素组合与等密度离心条件较适宜新疆杨愈伤组织原生质体的游离和纯化。     

玉米、小麦、水稻原生质体制备条件优化

玉米Zea mays L.、小麦Triticum aestivum L.、水稻Oryza sativaL.是三大重要粮食作物,对其原生质体制备条件的优化具有重要意义.以玉米(综3)、小麦(中国春)、水稻(日本晴)10日龄幼苗为材料,研究了叶肉细胞原生质体分离过程中的酶浓度、酶解时间和离心力大小等因素对产量和活力的影响.结果表明:酶浓度和酶解时间对原生质体产量影响显著,随着酶解液浓度和酶解时间的提高,原生质体产量增加,但细胞碎片同时增多.水稻经真空处理后,原生质体产量大幅度提高.通过正交实验设计得出如下结果:玉米叶肉细胞原生质体分离的最佳条件为:纤维素酶1.5％,离析酶0.5％,50 r/min酶解7h,100×g离心2 min收集,原生质体产量为7×106/g FW;小麦叶肉细胞原生质体分离的最佳条件为:纤维素酶1.5％,离析酶0.5％,50 r/min酶解5h,100×g离心2 min收集,原生质体产量为6×106/g FW;水稻叶肉细胞原生质体分离的最佳条件为:纤维素酶2.0％,离析酶0.7％,50 r/min酶解7h,1 000×g离心2 min收集,得到的原生质体产量为6×106/g FW.通过二乙酸荧光素染色发现原生质体活力均在90％以上.用PEG-Ca2+介导法将含有绿色荧光蛋白的质粒转化入原生质体,转化率可达50％ ～80％.     

普通小麦幼苗叶肉细胞原生质体分离方法的优化

以7日龄小麦幼苗的叶肉细胞为材料,采用正交试验分析了纤维素酶浓度、离析酶浓度、酶解时间、甘露醇浓度对原生质体分离时的产量和活力的影响;采用瞬时表达技术通过PEG-Ca~(2+)介导法转化小麦的原生质体,分析了PEG浓度对转化效率的影响。结果表明,小麦叶片原生质体分离的最佳条件为纤维素酶1.5%,离析酶0.75%,甘露醇0.4 mol/L,酶解时间3 h,得到的原生质体的产量可达到7.2×10~6个/g·FW,活力超过95%;瞬时表达实验结果表明,在25%PEG浓度下,小麦原生质体的转化效率最高。     

基于亚细胞定位的大豆和鹰嘴豆原生质体分离体系的建立与优化

以湘豆3号大豆和Kabuli型鹰嘴豆幼嫩叶片为材料,研究了酶解种类及配比、酶解液中甘露醇浓度、酶解液p H和酶解时间对两种豆科植物幼嫩叶片原生质体产量和存活率的影响。结果表明,湘豆3号大豆叶片在含有0.5%纤维素酶Onozuka R-10、0.8%半纤维素酶Hemicellulase、0.8%离析酶Macerozyme R-10、0.4%果胶酶Pectolyase Y-23、0.1%2-(N-吗啡啉)乙磺酸(MES)和10%甘露醇的酶解液中(pH 6.0),27℃黑暗条件下恒温水浴振荡(45 r/min)酶解6 h,分离得到的原生质体产量和存活率最高;Kabuli型鹰嘴豆叶片在含有0.5%纤维素酶Onozuka R-10、0.8%半纤维素酶Hemicellulase、0.8%离析酶Macerozyme R-10、0.1%MES和10%甘露醇酶解液中(pH 4.8),27℃黑暗条件下恒温振荡水浴(45 r/min)7–8 h,分离得到的原生质体产量和存活率最高。通过上述件分离到的湘豆3号大豆和Kabuli型鹰嘴豆幼嫩叶片原生质体用于亚细胞定位的效果最好。     

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.